HP Veritas Volume Manager 5.0 -UX 11i v3 specs

314Administering volume snapshots

Cascaded snapshots

Figure 9-5

Creating a snapshot of a snapshot

vxsnap make source=V

Original volume

V

Snapshot

volume

S1

vxsnap make source=S1

Snapshot

volume

S2

Even though the arrangement of the snapshots in this figure appears similar to the snapshot hierarchy shown in “Snapshot cascade” on page 312, the relationship between the snapshots is not recursive. When reading from the snapshot S2, data is obtained directly from the original volume, V, if it does not exist in S2 itself.

Such an arrangement may be useful if the snapshot volume, S1, is critical to the operation. For example, S1 could be used as a stable copy of the original volume, V. The additional snapshot volume, S2, can be used to restore the original volume if that volume becomes corrupted. For a database, you might need to replay a redo log on S2 before you could use it to restore V. These steps are illustrated in Figure 9-6.

Image 313

HP Veritas Volume Manager 5.0 -UX 11i v3 manual Creating a snapshot of a snapshot

Contents

Veritas Volume Manager Administrator’s Guide Legal Notices Page Contents VxVM root disk volume restrictions Using vxdiskadd to place a disk under control of VxVMBooting root volumes Setting up a VxVM root disk and mirror 119 Taking a disk offline 118133 136 185 167207 215 Setting default values for vxassist 241Displaying subdisk information 216 217 274 252275 288 Moving volumes from a VM disk 290289 290 356 Chapter Creating and administering volume sets 387 386388 390 441 434 463 Setup tasks after installation 511507 512 521 531 Understanding Veritas Volume Manager Veritas Enterprise Administrator User’s Guide How data is stored VxVM and the operating system Physical objects-physical disks How VxVM handles storage management Disk arrays Device discovery Multipathed disk arraysOperating system Enclosure-based naming Fibre Channel hub or switch C2t99d0 Provide redundant loop access Combining virtual objects in VxVM Virtual objectsVirtual objects in VxVM include the following Connection between objects in VxVM VM disks Disk groups Subdisks Plexes Volumes How VxVM handles storage management Disk01-01 vol06-01 Implementation of non-layered volumes Volume layouts in VxVMImplementation of layered volumes Concatenation and spanning Layout methodsFollowing sections describe each layout method 12 Example of concatenation Data Disk01-01 +1 n+2 Example of spanning Data Striping RAID-0 Su1 Su2 Su3 Devname3 Devname2 Striping plus mirroring mirrored-stripe or RAID-0+1 Mirroring RAID-1 Mirroring plus striping striped-mirror, RAID-1+0 or RAID-10 17 Mirrored-stripe volume laid out on six disks Column Mirror Striped plex You need a full license to use this feature Mirror volumesRAID-5 striping with parity Traditional RAID-5 arrays Data Parity Veritas Volume Manager RAID-5 arrays Left-symmetric layout 22 Veritas Volume Manager RAID-5 array Stripe Understanding Veritas Volume Manager RAID-5 logging Layered volumes Example of a striped-mirror layered volume Understanding Veritas Volume Manager How online relayout works Online relayout Three columns of length 5L/3 Striped volume Limitations of online relayout Transformations and volume length Transformation characteristics Dirty flags Volume resynchronizationResynchronization process Dirty region logs Dirty region logging Sequential DRL Log subdisks and plexes Data volume configuration SmartSync recovery accelerator Redo log volume configuration Volume snapshots Original Space than original Volume Comparison of snapshot featuresUse on creation Requires less storage FastResync Non-persistent FastResync FastResync enhancements Persistent FastResync DCO volume versioningHow non-persistent FastResync works with snapshots Version 20 DCO volume layout Version 0 DCO volume layout How persistent FastResync works with snapshots Where the size of each map in bytes is DCO FastResync Effect of growing a volume on the FastResync map FastResync limitations Hot-relocation Volume sets Volume sets Disk devices Administering disks Operating system-based naming Disk device naming in VxVMThere are two different methods of naming disk devices # vxdisk path egrep diskname Private and public disk regions To boot the system.Typically, most disks on a system are Configures disk access records for them automaticallyConfigured as this disk type. However, it is not a suitable Format for boot, root or swap disks, for mirrors or Following command scans for the devices c1t1d0 and c2t2d0 Discovering and configuring newly added disk devicesPartial device discovery Next example discovers fabric devices Disk categories Discovering disks and dynamically adding disk arraysFor more information, see the vxdisk1M manual Adding support for a new disk array Third-party driver coexistenceEnabling discovery of new devices Removing support for a disk array Listing details of supported disk arrays Administering the Device Discovery Layer# vxddladm listsupport all # vxddladm listsupport libname=libraryname.sl Re-including support for an excluded disk array library Excluding support for a disk array libraryListing excluded disk arrays Adding unsupported disk arrays to the Disks category Listing supported disks in the Disks category # vxddladm addjbod vid=SEAGATE pid=ST318404LSUN18G Length=serialnolength policy=ap# vxdmpadm listenclosure all # vxdisk list Adding foreign devices Removing disks from the Disks category# vxddladm rmjbod vid=SEAGATE See Migrating between DMP and HP-UX native multipathing on Placing disks under VxVM control Default Mode Format of output from VxVM commandChanging the disk-naming scheme Legacy # vxdmpadm getlungroup dmpnodename=disk25 VxVM vxdmpadm Error V-5-1-10910 Invalid da-name Regenerating persistent device names Restart the VxVM configuration demonThis regenerates the persistent name database # vxdmpadm setattr enclosure enclosure tpdmode=nativepseudo Changing device naming for TPD-controlled enclosures# vxdmpadm getsubpaths dmpnodename=enclosure-basedname # vxconfigd -kr reset Persistent simple or nopriv disks in the boot disk group Persistent simple or nopriv disks in non-boot disk groups Installing and formatting disksRe-import the disk group using the following command Add or initialize disks Menu VolumeManager/Disk/AddDisks Displaying and changing default disk layout attributesAdding a disk to VxVM C3t0d0 c3t1d0 c3t2d0 c3t3d0 Use default disk names for the disks? y,n,q,? default y Continue operation? y,n,q,? default y yExclude disks from hot-relocation use? y,n,q,? default n n Add site tag to disks? y,n,q,? default n Enter the desired format cdsdisk,hpdisk,q,? default cdsdisk Continue with operation? y,n,q,? default y yEnter desired private region length privlen,q,? default Following disks Add or initialize other disks? y,n,q,? default n Using vxdiskadd to place a disk under control of VxVMReinitializing a disk Vxdiskadm then proceeds to add the disks Rootability Root disk mirrors VxVM root disk volume restrictions Setting up a VxVM root disk and mirror Booting root volumes# /etc/vx/bin/vxcplvmroot -b c0t4d0 # /etc/vx/bin/vxcplvmroot -m c1t1d0 -R 30 -v -b c0t4d0 # /etc/vx/bin/vxcplvmroot -R 30 -v -b c0t4d0 Creating an LVM root disk from a VxVM root disk Adding persistent dump volumes to a VxVM rootable system Adding swap volumes to a VxVM rootable systemView the changed swap configuration Display the initial crash dump configuration You can now remove the volume if required Removing a persistent dump volume# crashconf -ds /dev/vx/dsk/bootdg/dumpvol Dynamic LUN expansion 109 Removing disks # vxvol -g diskgroup stop volume1 volume2 Remove another disk? y,n,q,? default n Continue with operation? y,n,q,? default yRemoving a disk with subdisks VxVM Info V-5-2-268 Removal of disk mydg01 is complete Removing a disk from VxVM control # /usr/lib/vxvm/bin/vxdiskunsetup c#t#d#Removing and replacing disks Removing a disk with no subdisks To replace a disk Are you sure you want do this? y,n,q,? default n# vxassist move mkting !mydg02 Removing and replacing disks Following devices are available as replacements c0t1d0 Replacing a failed or removed disk Following devices are available as replacements Replace another disk? y,n,q,? default n Select a disk device to enable address,list,q,? c0t2d0 Then run the following command on the master nodeEnabling a disk # vxreattach -r accesname Disable another device? y,n,q,? default n Enable another device? y,n,q,? default nTaking a disk offline Renaming a disk You would use the following command to rename the diskReserving disks See the vxedit1M manual page for more information Displaying disk informationVxVM returns a display similar to the following Enter disk device or all address,all,q,? default all List disk information Menu VolumeManager/Disk/ListDiskDisplaying disk information with vxdiskadm Setting the Pfto values Controlling Powerfail TimeoutTo set the Pfto value on a disk, use the following command Displaying the Pfto values Enabling or disabling Pfto For example, to disable Pfto on the disk c5t0d6 Controlling Powerfail Timeout How DMP works Administering dynamic multipathing DMP How DMP works Enc00 Path failover mechanism How DMP monitors I/O on paths Throttling Load balancing DMP coexistence with HP-UX native multipathing Use the following commands to initiate the migrationMigrating between DMP and HP-UX native multipathing # vxvol -g diskgroup stopall # vxvol -g diskgroup startall Restart all the volumes in each disk group Under the new naming scheme as DMP in a clustered environment Disabling multipathing and making devices invisible to VxVM Disabling and enabling multipathing for specific devicesEnabling or disabling controllers with shared disk groups Enabling multipathing and making devices visible to VxVM 135 Administering dynamic multipathing DMP Displaying DMP database information Typical output from the vxdisk list command is as followsDisplaying the paths to a disk Disabled Log Disabled ConfigDisabled Lockrgn C1t0d3 state=enabled Type=secondary Retrieving information about a DMP node Administering DMP using vxdmpadm# vxdmpadm getdmpnode nodename=c3t2d1 # vxdmpadm getdmpnode enclosure=enc0 Displaying the members of a LUN group# vxdmpadm getlungroup dmpnodename=c11t0d10 # vxdmpadm getsubpaths dmpnodename=c2t66d0 # vxdmpadm listctlr all Displaying information about controllers Displaying information about enclosures Following is example output from this commandDisplaying information about array ports Displaying information about TPD-controlled devices # vxdmpadm getsubpaths tpdnodename=emcpower10# vxdmpadm gettpdnode nodename=c7t0d10 To reset the I/O counters to zero, use this command Examples of using the vxdmpadm iostat commandGathering and displaying I/O statistics # vxdmpadm iostat show pathname=c3t115d0 # vxdmpadm iostat start memory=4096# vxdmpadm iostat show dmpnodename=c0t0d0 # vxdmpadm iostat show enclosure=Disk # vxdmpadm setattr path c2t10d0 pathtype=active Setting the attributes of the paths to an enclosure# vxdmpadm setattr path c3t10d0 pathtype=nomanual # vxdmpadm setattr path c1t20d0 pathtype=nopreferred Specifying the I/O policy Displaying the I/O policy Adaptive Following policies may be set# vxdmpadm setattr enclosure enc1 iopolicy=adaptive Adaptiveminq 048 # vxdmpadm setattr enclosure Disk iopolicy=minimumq This is the default I/O policy for Active/Active A/A arrays# vxdmpadm setattr arrayname Sena iopolicy=priority # vxdmpadm setattr arraytype A/A iopolicy=round-robin Example of applying load balancing in a SAN Default setting for this attribute is useallpaths=no# vxdmpadm setattr arrayname Disk iopolicy=singleactive # vxdisk list c3t2d15 # dd if=/dev/vx/rdsk/mydg/myvol1 of=/dev/null DMP statistics are now reset# vxdmpadm getattr enclosure ENC0 iopolicy # vxdmpadm -c-fdisable ctlr=ctlrname # vxdmpadm -c-fdisable path=pathnameDisabling I/O for paths, controllers or array ports # vxdmpadm setattr enclosure ENC0 iopolicy=singleactive # vxdmpadm enable ctlr=ctlrname # vxdmpadm enable path=pathnameEnabling I/O for paths, controllers or array ports Upgrading disk controller firmware Renaming an enclosure Re-enable the plex associated with the deviceStop I/O to all disks through one controller of the HBA For the other controller on the HBA, enter # vxdmpadm getattr enclosure enc0 recoveryoption Configuring the response to I/O failures# vxdmpadm setattr \ # vxdmpadm setattr arraytype A/A recoveryoption=default Configuring the I/O throttling mechanism # vxdmpadm setattr enclosure enc0 recoveryoption=nothrottle # vxdmpadm getattr enclosure HDS9500-ALUA0 recoveryoption Displaying recoveryoption valuesHDS9500-ALUA0 Error-Retry # vxdmpadm start restore interval=seconds policy=checkall Configuring DMP path restoration policies Displaying the status of the DMP path restoration thread Stopping the DMP path restoration threadThis produces output such as the following Configuring array policy modules Displaying information about the DMP error-handling threadTo add and configure an APM, use the following command One daemon should be shown as running # vxdmpadm -r cfgapm modulename Administering DMP using vxdmpadm Creating and administering disk groups Creating and administering disk groups Block special device corresponding to this volume is Specifying a disk group to commandsSystem-wide reserved disk groups To nodg Displaying the system-wide boot disk group Rules for determining the default disk group# vxdg bootdg See the vxdg1M manual page for more information # vxdg list Displaying disk group information# vxdg list diskgroup # vxdisk -s list devicename Displaying free space in a disk group Creating a disk groupFollowing is example output # vxdiskadd c1t0d0 Adding a disk to a disk group# vxdg init mktdg mktdg01=c1t0d0 # vxdg -g diskgroup set cds=onoff # vxdiskunsetup c1t0d0 # vxdiskunsetup devicenameRemoving a disk from a disk group # vxdg -g diskgroup rmdisk diskname Deporting a disk group Newdg Importing a disk group# vxdisk -s list Select another disk group? y,n,q,? default n Select disk group to import group,list,q,? default listHandling disks with duplicated identifiers VxVM Info V-5-2-374 The import of newdg was successful # vxdisk -f-g diskgroup updateudid disk Option to the vxdg import command, as shown in this# vxdisk updateudid c2t66d0 c2t67d0 Writing a new Udid to a disk # vxdisk -g diskgroup settag tagname disk # vxdg -o useclonedev=on -o updateid import mydg# vxdisk settag mytaggeddisks c2t66d0 c2t67d0 # vxdisk listtag Sample cases of operations on cloned disks Enabling configuration database copies on tagged disks# vxdg -q listmeta diskgroup # vxdg -o useclonedev=on -o tag=mytaggeddisks import mydg Importing cloned disks without tags # vxdg -g mydg set tagmeta=on tag=t1 nconfig=all nlog=all# vxdisk -o alldgs list To import only the cloned disks into the mydg disk group Symmir command is used to split off the BCV device# /usr/symcli/bin/symmir -g mydg split DEV001 Importing cloned disks with tags # vxdg -n newdg -o useclonedev=on -o updateid import mydgState of the cloned disk is now shown as online clonedisk Disks are tagged as follows # vxdisk set EMC08 clone=off # vxdisk -o alldgs list Renaming a disk group This command results in output such as the following Dgid 774226267.1025.tweety Moving disks between disk groups# vxdg -tC -n newdg import diskgroup Moving disk groups between systems # vxrecover -g diskgroup -sb To clear the locks during import, use the following command Handling errors when importing disks# vxdisk clearimport devicename # vxdg -C import diskgroup Reserving minor numbers for disk groups Following error message indicates a recoverable error# vxdg -f import diskgroup # vxprint -g mydg reminor # xvdg init newdg minor=30000 c1d0t0 c1t1d0 # vxdg -g diskgroup set maxdev=4079 Compatibility of disk groups between platforms Example of a serial split brain condition in a cluster Handling conflicting configuration copies 191 Typical arrangement of a 2-node campus cluster Expected a = Expected B = Automatically Imported on host Y # vxsplitlines -g newdg Correcting conflicting configuration information Reorganizing the contents of disk groups Reorganizing the contents of disk groups 197 Disk group join operation Limitations of disk group split and join Listing objects potentially affected by a move Moving DCO volumes between disk groups 201 Split Snapshot Moving objects between disk groups # vxdg -o expand move mydg rootdg mydg01 # vxprint Splitting disk groups Following commands would also achieve the same result# vxdg -o expand split rootdg mydg rootdg07 rootdg08 # vxdg -o overrideverify join sourcedg targetdg Joining disk groups Disabling a disk group Following command joins disk group mydg to rootdgMydg Mydg05 C1t96d0 Mydg06 C1t98d0 Destroying a disk group Recovering a destroyed disk groupUpgrading a disk group Use the disk group ID to import the disk group Upgrading a disk group Features supported by disk group versions # vxdg upgrade dgname To list the version of a disk group, use this command# vxdg list dgname # vxdg -T 120 init newdg newdg01=c0t3d0 Managing the configuration daemon in VxVM Using vxnotify to monitor configuration changes Backing up and restoring disk group configuration data# vxnotify -f # vxnotify -s Using vxnotify to monitor configuration changes # vxmake -g mydg sd mydg02-01 mydg02,0,8000 Creating subdisks Displaying subdisk information This command provides the following output# vxprint -st # vxprint -g diskgroup -l subdisk Splitting subdisks Moving subdisks# vxsd -g mydg mv mydg03-01 mydg12-01 mydg12-02 Associating subdisks with plexes Joining subdisks# vxmake -g diskgroup plex plex sd=subdisk # vxsd -g mydg -l 4096b assoc vol10-01 mydg15-01 # vxsd -g mydg assoc home-1 mydg02-01 mydg02-00 mydg02-01# vxsd -g mydg -l 1 assoc vol02-01 mydg11-01 # vxsd -g diskgroup assoc plex subdisk10 ... subdiskMN-1 Associating log subdisks # vxassist -g diskgroup addlog volume disk# vxsd -g diskgroup aslog plex subdisk # vxsd -g mydg aslog vol01-02 mydg02-01 Dissociating subdisks from plexes To remove a subdisk, use the following commandRemoving subdisks Changing subdisk attributes # vxedit -g mydg set putil0=DO-NOT-USE mydg02-01 # vxedit -g mydg set comment=subdisk comment mydg02-01 # vxmake -g mydg plex vol01-02 sd=mydg02-01,mydg02-02 Creating plexes Displaying plex information Creating a striped plexPlex states Active plex state Clean plex stateDcosnp plex state Iofail plex state Empty plex stateLOG plex state Offline plex state Stale plex state Snaptmp plex stateTemp plex state Temprm plex state Plex condition flags Enabled plex kernel state Disabled plex kernel stateAttaching and associating plexes Plex kernel states # vxmend -g diskgroup off plex Taking plexes offline# vxmend -g mydg off vol01-02 vol02-02 Reattaching plexes Detaching plexes # vxmend -g diskgroup fix clean plex Start the volume using the following command# vxvol -g diskgroup start volume Moving plexes # vxplex -g diskgroup cp volume newplex Copying volumes to plexesDissociating and removing plexes # vxplex -g diskgroup -o rm dis plex # vxedit -g diskgroup set attribute=value ... plex Changing plex attributes# vxedit -g mydg set comment=plex comment tutil2=u vol01-02 # vxedit -g mydg set putil0=DO-NOT-USE vol01-02 Creating volumes RAID-5 Types of volume layouts Mirror and concatenated-mirror volumes Supported volume logs and maps Advanced approach Creating a volume Assisted approach Using vxassist Vxassist # vxassist options make volume length attributes Following is a sample vxassist defaults file Setting default values for vxassist Disk group alignment constraints on volumes Discovering the maximum size of a volume# vxassist -g diskgroup maxsize layout=layout attributes # vxassist -g dgrp maxsize layout=raid5 nlog=2 # vxassist -b -g diskgroup make volume length Creating a volume on any disk# vxassist -b make voldefault 10g # vxprint -g diskgroup -G -F %align # vxassist -b -g mydg make volspec 5g mydg03 mydg04 Creating a volume on specific disks# vxassist -b -g mydg make volspec 5g ctlrc1 !targetc1t5 Specifying ordered allocation of storage to volumes Mydg01 mydg02 mydg03 mydg04 mydg05 mydg06 mydg07 mydg08 Stripe volume Volume across controllers Creating a mirrored-concatenated volume Creating a mirrored volumeCreating a concatenated-mirror volume # vxassist -b -g mydg make volmir 5g layout=mirror Creating a volume with a version 0 DCO volume # vxvol -g diskgroup set logtype=drldrlseq volume # vxdg -T 90 upgrade diskgroupFor more information, see Upgrading a disk group on Creating a volume with dirty region logging enabled Creating a volume with a version 20 DCO volume# vxdg upgrade diskgroup # vxassist -b -g diskgroup make volume length layout=stripe Creating a striped volume# vxassist -b -g mydg make volzebra 10g layout=stripe Creating a striped-mirror volume Creating a mirrored-stripe volume Mirroring across targets, controllers or enclosures # vxassist -b -g mydg make volraid 10g layout=raid5 nlog=2 Creating a RAID-5 volume # vxassist -g diskgroup listtag volume Creating tagged volumes# vxassist -g diskgroup list tag=tagname volume Creating a volume using vxmake # vxmake -g diskgroup -d descriptionfile Creating a volume using a vxmake description file # vxassist -b -g diskgroup make volume length layout=mirror Initializing and starting a volumeMydg04-021/8000,mydg04-031/16000 # vxvol -g diskgroup init enable volume Initializing and starting a volume created using vxmake# vxvol -g diskgroup init active volume # vxvol -g diskgroup init zero volume Accessing a volume Administering volumes Vxprint command can also be applied to a single disk group Displaying volume informationThis is example output from this command Active volume state Volume statesClean volume state Empty volume state Invalid volume state Volume kernel statesNeedsync volume state Replay volume state Disabled volume kernel state Detached volume kernel stateEnabled volume kernel state Monitoring and controlling tasks Vxtask operations Managing tasks with vxtask Using the vxtask command Putting a volume in maintenance mode Stopping a volume Adding a mirror to a volume Starting a volumeTo start all Disabled volumes, enter Mirroring volumes on a VM disk Mirroring all volumes# /etc/vx/bin/vxmirror -g diskgroup -a # /etc/vx/bin/vxmirror -d yes # vxassist -gdiskgroup remove mirror volume Mirror volumes on another disk? y,n,q,? default nRemoving a mirror At the following prompt, press Return to make the mirror Adding logs and maps to volumes Preparing a volume for DRL and instant snapshots Specifying storage for version 20 DCO plexes # DCONAME=‘vxprint -g diskgroup -F%dconame volume‘ Using a DCO and DCO volume with a RAID-5 volumeDetermining the DCO version number # vxprint -g diskgroup -F%version $DCONAME Determining if DRL logging is active on a volume Determining if DRL is enabled on a volumeThis command returns on if DRL logging is enabled Disabling and re-enabling DRL To re-enable DRL on a volume, enter this command Upgrading existing volumes to use version 20 DCOsTo re-enable sequential DRL on a volume, enter Use the following command on the volume to upgrade it Adding traditional DRL logging to a mirrored volume # vxassist -g mydg addlog volume logtype=drlseq nlog=n To remove a DRL log, use the vxassist command as followsRemoving a traditional DRL log # vxassist -g mydg addlog vol03 logtype=drl # vxassist -b -g diskgroup addlog volume loglen=length Adding a RAID-5 log using vxplexAdding a RAID-5 log # vxassist -g mydg addlog volraid # vxprint -g diskgroup -ht volume Resizing a volume# vxassist -g diskgroup maxgrow volume Removing a RAID-5 log Online JFS Full Base JFS Lite Resizing volumes using vxresizeVxFS Mounted File System Unmounted File System Extending to a given length Resizing volumes using vxassistExtending by a given length Shrinking to a given length Resizing volumes using vxvolShrinking by a given length # vxassist -g diskgroup removetag volume tagname Setting tags on volumes Changing the read policy for mirrored volumes Moving volumes from a VM disk Removing a volumeTo set the read policy to select, use the following command Move volumes from another disk? y,n,q,? default n To move volumes from a diskVxVM vxevac Info VxVM Info V-5-2-188 Evacuation of disk mydg02 is complete # vxvol -g diskgroup set fastresync=on volume Enabling FastResync on a volume # vxprint -g diskgroup -F%fastresync volume Checking whether FastResync is enabled on a volume# vxprint -g diskgroup -F%hasdcolog volume Disabling FastResync # vxassist -g mydg relayout vol02 layout=stripe Performing online relayout Permitted relayout transformations Relayout to From raid5 Concat Supported relayout transformations for RAID-5 volumesRelayout to From mirror-concat Concat Mirror-concat Mirror-stripe Relayout to From mirror-stripe Concat Layered striped-mirror volumesSupported relayout transformations for unmirrored stripe Relayout to From stripe or stripe-mirror Concat Specifying a plex for relayout Specifying a non-default layoutTagging a relayout operation # vxassist -g fsgrp relayout vol04 layout=raid5 ncol=4 Viewing the status of a relayout To resume the operation, use the vxtask commandControlling the progress of a relayout # vxrelayout -g mydg -o bg,slow=1000,iosize=10m start vol04 Converting between layered and non-layered volumes# vxrelayout -g mydg -o bg reverse vol04 # vxassist -g mydg relayout vol1 ncol=5 # vxassist -g mydg convert vol1 layout=mirror-stripe Converting between layered and non-layered volumes Administering volume snapshots Administering volume snapshots Traditional third-mirror break-off snapshots Independent Volume Vxassist snapclear Traditional third-mirror break-off snapshots Full-sized instant snapshots 308 Administering volume snapshots Cycle Start Vxsnap make Vxsnap refresh Vxsnap prepare Space-optimized instant snapshots Emulation of third-mirror break-off snapshots Linked break-off snapshot volumes Cascaded snapshots Cascaded snapshots Creating a snapshot of a snapshot Creating a snapshot of a snapshot Create instant snapshot S2 of S1 Vxsnap make source=S1 Vxsnap dis S2 Creating multiple snapshots Restoring the original volume from a snapshot Restoring the original volume from a snapshot Creating instant snapshots Creating instant snapshots Preparing to create instant and break-off snapshots Creating a shared cache object For example to start the cache object, cobjmydg # LEN=‘vxprint -g diskgroup -F%len volume‘# vxcache -g mydg start cobjmydg # RSZ=‘vxprint -g diskgroup -F%regionsz $DCONAME‘ Creating and managing space-optimized instant snapshots Creating instant snapshots # fsck -F vxfs /dev/vx/rdsk/diskgroup/snapshot # vxsnap -g mydg make source=myvol/snapvol=snap1myvol Creating and managing full-sized instant snapshots# vxsnap -g diskgroup syncwait snapvol # vxsnap -g mydg syncwait snap2myvol # vxprint -gdiskgroup -F%incompletesnapvol # vxsnap -g mydg addmir vol1 nmirror=2 alloc=mydg10,mydg11 Creating and managing third-mirror break-off snapshots # vxsnap -g mydg snapwait vol1 nmirror=2 # vxsnap -g diskgroup -b addmir volume mirvol=snapvol \ Creating and managing linked break-off snapshot volumes Mirdg=snapdg Creating multiple instant snapshots Reattach the snapshot volume with the original volume. See# vxsnap -g diskgroup make \ # vxsnap -g diskgroup make source=vol1/snapvol=snapvol1 \ # vxvset -g mydg list vset1 Creating instant snapshots of volume sets# vxvset -g mydg list snapvset1 Svol1 409600 Svol0 204800Svol2 614400 Removing a snapshot mirror Adding snapshot mirrors to a volume# vxsnap -g mydg rmmir vol1 Adding a snapshot to a cascaded snapshot hierarchy Removing a linked break-off snapshot volumeRefreshing an instant snapshot # vxsnap -g mydg rmmir vol1 mirvol=prepsnap mirdg=mysnapdg # vxsnap -g mydg reattach snapmyvol source=myvol nmirror=1 Reattaching an instant snapshot # vxsnap -g mydg snapwait myvol nmirror=1 Reattaching a linked break-off snapshot volume # vxsnap -g mydg restore myvol source=snap3myvol Restoring a volume from an instant snapshotDissociating an instant snapshot # vxsnap -g snapdg snapwait myvol mirvol=prepsnap Splitting an instant snapshot hierarchy Removing an instant snapshot# vxsnap -g mydg dis snap2myvol # vxedit -g mydg -r rm snap2myvol # vxsnap -g mydg split snap2myvol Displaying instant snapshot information# vxsnap -g diskgroup print vol # vxsnap -g mydg print # vxsnap -g dg -vx list # vxsnap -g diskgroup -l -v -x list vol Vxsnap -g diskgroup syncresume \ Controlling instant snapshot synchronizationVxsnap -b -g diskgroup syncstart \ Vxsnap -g diskgroup syncstop vol volset Improving the performance of snapshot synchronization Listing the snapshots created on a cache# vxcache -g diskgroup listvol cacheobject # vxcache -g mydg set highwatermark=60 cobjmydg Tuning the autogrow attributes of a cache Growing and shrinking a cache Finally, remove the cache object and its cache volumeRemoving a cache Creating traditional third-mirror break-off snapshots # vxassist -g diskgroup snapwait volume # vxassist -b -g diskgroup snapstart nmirror=N volume# vxassist -g diskgroup snapstart voldef # vxassist -g diskgroup snapshot nmirror=N volume snapshot Create a snapshot volume using the following command# vxassist -g diskgroup snapshot voldef snapvol # vxedit -g diskgroup -rf rm snapshot Converting a plex into a snapshot plex Creating multiple snapshots Reattaching a snapshot volume# vxplex -g diskgroup convert state=SNAPDONE plex # vxassist -g diskgroup -o allvols snapshot # vxassist -g diskgroup -o allplexes snapback snapshot Adding plexes to a snapshot volume# vxassist -g diskgroup snapback nmirror=number snapshot # vxprint -g diskgroup -F%rid $DCOVOL Dissociating a snapshot volume# vxassist snapclear snapshot # vxassist snapprint volume Output from this command is shown in the following examplesDisplaying snapshot information # vxassist -g mydg snapprint Adding a version 0 DCO and DCO volume Specifying storage for version 0 DCO plexes # vxdco -g diskgroup -o rm dis dcoobj Removing a version 0 DCO and DCO volume# vxdco -g mydg dis myvoldco For more information, see the vxdco1M manual Reattaching a version 0 DCO and DCO volume# vxdco -g mydg att myvol myvoldco Adding a version 0 DCO and DCO volume Creating and administering volume sets Adding a volume to a volume set Creating a volume set Stopping and starting volume sets Listing details of volume sets Raw device node access to component volumes Removing a volume from a volume set# vxvset -g diskgroup -f rmvol volset volume # vxvset -g mydg start set1 # vxvset -g mydg list set1 Enabling raw device access when creating a volume set Controlling raw device access for an existing volume set Displaying the raw device access settings for a volume set# vxvset -g diskgroup -fset makedev=onoff vset # vxvset -g mydg set makedev=on myvset2 # vxvset -g mydg set compvolaccess=read-write myvset2# vxvset -g mydg set makedev=off myvset2 Raw device node access to component volumes Configuring off-host processing Example implementation of off-host processing Implementing off-host processing solutions # vxprint -g volumedg -F%instant volume Implementing off-host online backup # vxvol -g volumedg set fastresync=on volume # vxdg import snapvoldg # vxdg deport snapvoldg# fsck -F vxfs /dev/vx/rdsk/snapvoldg/snapvol # vxprint -g volumedg -F%instantvolume # vxsnap -g volumedg snapwait volume mirvol=snapvolImplementing decision support 375 # mount -F vxfs /dev/vx/dsk/snapvoldg/snapvol \ mountpoint You can then resume the procedure from on Implementing off-host processing solutions Administering hot-relocation How hot-relocation works 381 Mydg05 Partial disk failure mail messages # vxrecover -b -g mydg home src# vxstat -g mydg -s -ff home-02 src-02 Sd mydg01-04 Sd mydg01-06 Sd mydg02-03 Sd mydg02-04 How space is chosen for relocation Complete disk failure mail messagesFailing disks mydg02 Configuring a system for hot-relocation # vxdg -g diskgroup spare Displaying spare disk informationMydg mydg02 C0t2d0 658007 Marking a disk as a hot-relocation spare Mark another disk as a spare? y,n,q,? default n# vxedit -g mydg set spare=on mydg01 Removing a disk from use as a hot-relocation spare Where diskname is the disk media nameExcluding a disk from hot-relocation use Following confirmation is displayed To use vxdiskadm to exclude a disk from hot-relocation use Making a disk available for hot-relocation use# vxedit -g diskgroup set nohotuse=off diskname Moving and unrelocating subdisks Configuring hot-relocation to use only spare disksSpare=only To root Subject Attempting VxVM relocation on host teal Unrelocate to a new disk y,n,q,? default n Moving and unrelocating subdisks using vxdiskadmStatus message is displayed at the end of the operation Enter the original disk name disk,list,q,? Moving and unrelocating subdisks using vxunreloc Moving and unrelocating subdisks using vxassist# vxassist -g mydg move home !mydg05 mydg02 Moving hot-relocated subdisks back to a different disk Moving hot-relocated subdisks back to their original diskForcing hot-relocated subdisks to accept different offsets Examining which subdisks were hot-relocated from a disk Restarting vxunreloc after errors# vxprint -g mydg -se sdorigdmname=mydg01 Modifying the behavior of hot-relocation Nohup vxrelocd -o slow=IOdelay root# nohup vxrelocd root Nohup vxrelocd root user1 user2 See the vxrelocd1M manual page for more information Alternatively, you can use the following command# nohup /etc/vx/bin/vxrelocd root user1 user2 Administering cluster functionality Overview of cluster volume management 399 Example of a 4-node cluster Two types of disk groups are defined Private and shared disk groups Exclusivewrite ew Activation modes of shared disk groupsReadonly ro Sharedread sr Enableactivation=true Defaultactivationmode=activation-mode Activation mode DescriptionActivation modes for shared disk groups Sharedwrite sw Connectivity policy of shared disk groups Global detach policy Local detach policy Disk group failure policy Guidelines for choosing detach and failure policies Limitations of shared disk groups Effect of disk connectivity on cluster reconfiguration Cluster reconfiguration Cluster initialization and configuration Various reasons that may be given are shown in Table Vxclustadm utility# /etc/vx/bin/vxclustadm nodestate state out of cluster Reason user initiated stop Reason Description Node abort messages Volume reconfiguration Vxconfigd daemon recovery Vxconfigd daemon # hagrp -unfreeze group # hagrp -freeze group Node shutdown Node abort Multiple host failover configurationsCluster shutdown Failover Import lock Where the reason can describe errors such as Corruption of disk group configuration # vxdctl -c mode Administering VxVM in cluster environmentsRequesting node status and discovering the master node See the vxdctl1M manual page for more information Example output from this command is as follows Example output from this command is displayed hereDetermining if a disk is shareable Listing shared disk groups # vxdg -s init diskgroup diskname=devicename Creating a shared disk group Forcibly importing a disk group Importing disk groups as shared# vxdg -s import diskgroup # vxdg -s -f import diskgroup Converting a disk group from shared to private Setting the disk detach policy on a shared disk group Changing the activation mode on a shared disk groupDefault disk detach policy is global # vxdg -g diskgroup set activation=mode Setting exclusive open access to a volume by a node Creating volumes with exclusive open access by a node# vxdg -g diskgroup set dgfailpolicy=dgdisableleave # vxvol -g dskgrp set exclusive=on volmir This command produces out put similar to the following This command produces output similar to the followingDisplaying the cluster protocol version Displaying the supported cluster protocol version range Upgrading the cluster protocol version Recovering volumes in shared disk groupsObtaining cluster performance statistics # vxstat -b Vol Vol1 2421 600000 99.0 Administering VxVM in cluster environments Administering Sites and remote mirrors Site-consistent volume with two plexes at each of two sites Example of a two-site configuration with remote storage only Configuring site-based allocation on a disk group Configuring sites for hosts and disksTo remove the site name from a host, use this command Configuring site consistency on a volume Configuring site consistency on a disk group# vxdg -g diskgroup set siteconsistent=on # vxdg -g diskgroup set siteconsistent=off Site-based allocation of storage to volumes Setting the siteread policy on a volumeRAID-5 volumes in a site-consistent disk group # vxassist -g diskgroup make volume size mirror=site Command Description Examples of storage allocation using sites Making an existing disk group site consistent Turn on site consistency for each volume in the disk groupRegister a site record for each site with the disk group Turn on site consistency for the disk group Recovery from simulated site failure Fire drill testing the configurationAutomatic site reattachment Simulating site failure # ps -afe Failure scenarios and recovery procedures# kill -9 PID Recovery from host failure Recovery from a loss of site connectivityRecovery from storage failure Failure scenario Recovery technique Recovery from site failure Failure scenarios and recovery procedures See the vxse1M manual About Storage Expert How Storage Expert works Before using Storage ExpertRunning Storage Expert One of the following keywords must be specified Discovering what a rule does Displaying rule attributes and their default valuesRunning a rule # vxsestripes2 info Rule result types Setting rule attributes Recovery time Identifying configuration problems using Storage Expert Checking for non-mirrored RAID-5 logs vxseraid5log3 Checking minimum and maximum RAID-5 log sizes vxseraid5log2Vxseraid5log1 Checking on disk config size vxsedg3 Checking disk group configuration copies and logs vxsedg2Disk groups Checking the version number of disk groups vxsedg4 Checking states of plexes and volumes vxsevolplex Checking volume redundancy vxseredundancyChecking for non-imported disk groups vxsedg6 Volumes needing recovery Checking the number of columns in RAID-5 volumes vxseraid5Disk striping Hardware failures Disk sparing and relocation managementRootability System name Checking the system name vxsehost Rule definitions and attributes See Running a rule on Rule Description Rule Attribute Default Description Value Vxseraid5 Toonarrowraid5 NsdthresholdToowideraid5 R5maxsize Vxsestripes1 Default stripeunit Vxseredundancy VolumeredundancyVxserootmir Vxsespares Vxsevolplex Rule definitions and attributes Data assignment Performance guidelines Mirroring Striping RAID-5 Combining mirroring and striping Volume read policies Performance monitoring Setting performance prioritiesObtaining performance data Printing volume statistics Tracing volume operationsBy vxtrace Using I/O statistics Using performance data # vxprint -g mydg -tvh archive Following is an extract from typical outputMydg03-03 Archive-01 40960 C1t2d0 # vxassist -g mydg move archive !mydg03 destdisk 471 General tuning guidelines Tuning VxVMUsing I/O tracing Number of configuration copies for a disk group Tuning guidelines for large systems Changing the values of tunables # vxedit set nconfig=5 bigdg# vxdmpadm settune dmptunable=value # vxdmpadm gettune dmptunable Tunable parameters Dmphealthtime DmppathswitchblksshiftDmploglevel Dmppathage Dmprestoreinterval DmprestorecyclesDmpprobeidlelun Dmpqueuedepth Dmpretrytimeout DmprestorepolicyDmpscsitimeout Dmpretrycount Voldefaultiodelay VolcheckptdefaultDmpstatinterval Volfmrlogsz Volmaxio VolmaxvolVolmaxioctl Volmaxspecialio VolmaxparallelioVolsubdisknum Voldrlmaxdrtregs VolcvmsmartsyncVoldrlmaxseqdirty Voldrlminregionsz Voliomemmaxpoolsz VoliotiobufdefaultVolioterrbufdflt Voliotiobuflimit Voliotmaxopen VoliotiobufmaxVolpagemodmaxmemsz Volraidrsrtransmax Volraidminpoolsz Tuning VxVM If you are using a C shell csh or tcsh, use the commands Commands summary # vxdisk -g mydg list Vxdisk -g diskgroup list disknameVxdg list diskgroup # vxdg list mydg Table A-2 Administering disks Command Description Mydg03 mydg02 # vxedit -g mydg rename \# vxedit -g mydg set \ Reserve=on mydg02 Spare=on mydg04 # vxdiskunsetup c0t3d0Spare=off mydg04 # vxdisk offline c0t1d0 Mydg01=c0t1d0 # vxdg init mydg \# vxsplitlines -g mydg # vxdg -n newdg deport mydg Mydg newdg myvol1 # vxdg -o expand listmove \Newdg myvol1 Newdg myvol2 myvol3 # vxdg destroy mydg # vxrecover -g mydg -sb# vxmake -g mydg sd \ Mydg02-01 mydg02,0,8000 Vol01-01 mydg10-010 \ # vxsd -g mydg assoc \Mydg11-011 mydg12-012 Mydg02-01 # vxmake -g mydg plex \ # vxsd -g mydg -o rm dis \Vol01-02 \ Sd=mydg02-01,mydg02-02 # vxplex -g mydg mv \ Vol01-02Vol02-02 vol02-03 # vxplex -g mydg cp vol02 \ Table A-6 Creating volumes Command DescriptionVol03-01 Vol02-02 Vxassist -b -g diskgroup make \ Volume length layout=striperaid5 \Stripeunit=W ncol=N attributes Mysvol 20g layout=stripe \ Vol r5vol \ # vxmake -g mydg -Uraid5\Plex=raidplex,raidlog1,\ Raidlog2 Table A-7 Administering volumes Command Description # vxsnap -gmydg prepare \ myvol drl=on Drl=onsequentialoff Cvol 1g layout=mirror \ # vxassist -g mydg make \Init=active mydg16 mydg17 Cachevolname=cvol # vxassist -gmydg relayout \ vol2 layout=stripe # vxsnap -g mydg unprepare \ myvolVol3 layout=raid5 \ Stripeunit=16 ncol=4 # vxassist -g mydg remove \ myvol # vxrecover -g mydg \Mytask -b mydg05 # vxtask -h -g mydg list # vxtask -p -g mydg list # vxtask pause mytask# vxtask resume mytask # vxtask abort mytask Online manual pages Administrative commands Table A-9 Manual pages Name Description Vxmend VxrecoverVxmirror Vxnotify Device driver interfaces File formats Setup tasks after installation Configuring Veritas Volume Manager Adding foreign devices Adding unsupported disk arrays as JBODsAdding disks to disk groups Guidelines for configuring storage Mirroring guidelines Striping guidelines Dirty region logging guidelines Hot-relocation guidelines RAID-5 guidelines 517 Accessing volume devices Configuring cluster supportControlling VxVM’s view of multipathed devices Converting existing VxVM disk groups to shared disk groups Configuring shared disk groups Reconfiguration tasks Glossary Single copy of a configuration database Page See disk enclosure Jbod Page RAID Page Page Page Index CDS Page CVM Page Page DMP Empty Page Page Page Page Iofail 228 Nodarec 228 Nodevice 228 Recover 228 Removed Page Page Page Page Page TPD Page Detached Disabled Enabled Page Page Page Page Page