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Legal Notices
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Chapter
Understanding Veritas Volume Manager
Administering disks
Administering dynamic multipathing (DMP)
Creating and administering disk groups
Chapter 5 Creating and administering subdisks
Creating and administering plexes
Creating volumes
Administering volumes
Administering volume snapshots
Creating and administering volume sets
Configuring off-hostprocessing
Administering hot-relocation
Administering cluster functionality
Administering
sites and remote mirrors
Using Storage Expert
Performance monitoring and tuning
Appendix A
Commands summary
Appendix B
Configuring Veritas Volume Manager
Glossary
Index
Understanding Veritas
Volume Manager
Page
VxVM and the operating system
How VxVM handles storage management
VxVM accesses all disks as entire physical disks without partitions
Disk arrays
balance
Multipathed disk arrays
Device discovery
Enclosure-basednaming
channel hub or switch
enc0_0
enc0_1
Page
for details of the standard and the
enclosure-based
naming schemes, and how to switch between them
Virtual objects
Virtual objects in VxVM include the following:
■Disk groups
■VM disks
■Subdisks
■Volumes are composed of one or more plexes
vol01
vol02
Disk groups
VM disks
Subdisks
Plexes
Volumes
Page
Page
Volume layouts in VxVM
Layout methods
Concatenation and spanning
Page
Page
Striping (RAID-0)
Figure 1-14Striping across three columns
Stripe
su1
su2
su3
Page
Page
Mirroring (RAID-1)
Mirroring
different
Disk duplexing
Striping plus mirroring (mirrored-stripeor RAID-0+1)
Mirroring plus striping (striped-mirror, RAID-1+0or RAID-10)
Page
RAID-5(striping with parity)
Data Data Parity
Data Parity Data
Parity Data Data
Traditional RAID-5arrays
Veritas Volume Manager RAID-5arrays
Left-symmetriclayout
Page
RAID-5logging
Layered volumes
Page
Page
Online relayout
Page
Page
Figure 1-30Example of increasing the stripe width for the columns in a volume
Limitations of online relayout
Note the following limitations of online relayout:
■Log plexes cannot be transformed
Online relayout involving
■The number of mirrors in a mirrored volume cannot be changed using relayout
Transformation characteristics
You can determine the transformation direction by using the
Transformations and volume length
Resizing a volume
Volume resynchronization
Dirty region logging
Log subdisks and plexes
log plex
Sequential DRL
voldrl_max_seq_dirty
Note: DRL adds a small I/O overhead for most write access patterns
SmartSync recovery accelerator
Data volume configuration
Volume snapshots
Page
Comparison of snapshot features
FastResync
FastResync enhancements
FastResync provides two fundamental enhancements to VxVM:
detached
returning mirror
FastResync allows you to refresh and
How non-persistentFastResync works with snapshots
Persistent FastResync
DCO volume versioning
Version 0 DCO volume layout
Version 20 DCO volume layout
where the size of each map in bytes is:
How persistent FastResync works with snapshots
Figure 1-32Mirrored volume with persistent FastResync enabled
Mirrored volume
DCO DCO
plex plex
Figure 1-33Mirrored volume after completion of a snapstart operation
snap objects
For traditional snapshots, the
For
Effect of growing a volume on the FastResync map
FastResync limitations
The following limitations apply to FastResync:
Persistent FastResync is supported for
Neither
Hot-relocation
Volume sets
Page
Administering disks
Disk devices
Disk devices
/dev/rdisk
/dev/dsk
Disk device naming in VxVM
There are two different methods of naming disk devices:
■Operating system-basednaming
■Enclosure-basednaming
Operating system-basednaming
Page
Private and public disk regions
Most VM disks have two regions:
” on page 205)
smallest
the public area following the private area)
When the vxconfigd daemon is started, VxVM obtains a list of
known disk device addresses from the operating system and
configures disk access records for them automatically
cdsdisk
disk that is suitable for moving between different operating
Discovering and configuring newly added disk devices
except
#vxdisk scandisks !device=c1t1d0,c2t2d0
#vxdisk scandisks !ctlr=c1,c2
#vxdisk scandisks pctlr=8/12.8.0.255.0
Discovering disks and dynamically adding disk arrays
third-party
vendor. The support comes in the form of
vendor-supplied
libraries, and is added to an
Adding support for a new disk array
Enabling discovery of new devices
Removing support for a disk array
Third-partydriver coexistence
Administering the Device Discovery Layer
Listing details of supported disk arrays
Excluding support for a disk array library
Re-includingsupport for an excluded disk array library
Listing excluded disk arrays
Listing supported disks in the DISKS category
Adding unsupported disk arrays to the DISKS category
[length=serialno_length] [policy=ap]
vendorid
productid
FUJITSU
IBM
Removing disks from the DISKS category
Adding foreign devices
Placing disks under VxVM control
Changing the disk-namingscheme
The following examples illustrate the use of
command:
Regenerating persistent device names
Changing device naming for TPD-controlledenclosures
#vxdmpadm setattr enclosure enclosure tpdmode=native|pseudo
native
Discovering the association between enclosure and OS based disk names
#vxdisk list enclosure-based_name
Persistent simple or nopriv disks in the boot disk group
Installing and formatting disks
Displaying and changing default disk layout attributes
Adding a disk to VxVM
Adding a disk to VxVM
<pattern-list
c3t0d0 c3t1d0 c3t2d0 c3t3d0
specifies fours disks at separate target IDs on controller
To continue with the operation, enter
Here are the disks selected. Output format: [Device]
list of device names
Continue operation? [y,n,q,?] (default: y) y
Which disk group [<group>,none,list,q,?]
step
site_name
If one or more disks already contains a file system
At the following prompt
vxdiskadm then proceeds to add the disks
Reinitializing a disk
Using vxdiskadd to place a disk under control of VxVM
#vxdiskadd c0t1d0
Rootability
VxVM root disk volume restrictions
Root disk mirrors
Booting root volumes
Setting up a VxVM root disk and mirror
primary
#/etc/vx/bin/vxcp_lvmroot -R30 -v -bc0t4d0
#/etc/vx/bin/vxcp_lvmroot -mc1t1d0 -R30 -v -bc0t4d0
alternate
#/etc/vx/bin/vxrootmir -v -bc1t1d0
Creating an LVM root disk from a VxVM root disk
vxres_lvmroot
#/etc/vx/bin/vxdestroy_lvmroot -vc0t1d0
#/etc/vx/bin/vxres_lvmroot -v -bc0t1d0
The -b option to vxres_lvmroot sets c0t1d0 as the primary boot device
Adding swap volumes to a VxVM rootable system
Adding persistent dump volumes to a VxVM rootable system
Dynamic LUN expansion
Page
Removing disks
Removing a disk with subdisks
Removing a disk from VxVM control
Removing and replacing disks
To replace a disk
At the following prompt, enter the name of the disk to be replaced (or enter
Remove a disk for replacement
Menu: VolumeManager/Disk/RemoveForReplace
home src
114Administering disks
The following devices are available as replacements: c0t1d0
You can choose one of these disks now, to replace mydg02
Select “none” if you do not wish to select a replacement disk
VxVM NOTICE V-5-2-265Removal of disk mydg02 completed successfully
Replacing a failed or removed disk
To specify a disk that has replaced a failed or removed disk
116Administering disks
c0t1d0 c1t1d0
You can choose one of these disks to replace mydg02
Choose "none" to initialize another disk to replace mydg02
Replace another disk? [y,n,q,?] (default: n)
Enabling a disk
Taking a disk offline
Renaming a disk
Reserving disks
Displaying disk information
Displaying disk information with vxdiskadm
To display disk information
Start the
list (List disk information)
all
Controlling Powerfail Timeout
Enabling or disabling PFTO
Page
Administering dynamic multipathing (DMP)
How DMP works
Page
naming
c2t99d0
enc0_0
How DMP monitors I/O on paths
I/O throttling
Path failover mechanism
I/O throttling
Path failover mechanism
I/O throttling
Load balancing
DMP coexistence with HP-UXnative multipathing
See “Changing the disk-namingscheme” on page
See “Adding foreign devices” on page
Migrating between DMP and HP-UXnative multipathing
You can use the
3Restart all the volumes in each disk group:
#vxvol -g diskgroup startall
To migrate from HP-UXnative multipathing to DMP
#vxddladm rmforeign blockdir=/dev/disk chardir=/dev/rdisk
DMP in a clustered environment
Disabling and enabling multipathing for specific devices
◆Select option 2 to exclude specified paths from the view of VxVM
Enabling multipathing and making devices visible to VxVM
Select menu item 18
main menu to
re-enable
◆Select option 2 to make specified paths visible to VxVM
◆Select option 6 to enable multipathing for specified paths
Enabling and disabling I/O for controllers and storage processors
Displaying DMP database information
Displaying the paths to a disk
Page
Administering DMP using vxdmpadm
The above command displays output such as the following:
#vxdmpadm getdmpnode enclosure=enc0
Displaying the members of a LUN group
#vxdmpadm getlungroup dmpnodename=c11t0d10
Displaying paths controlled by a DMP node, controller or array port
command combined with the
directory:
Displaying information about controllers
operations being disabled on that controller by using the
#vxdmpadm listctlr enclosure=enc0 type=ACME
Displaying information about enclosures
#vxdmpadm listenclosure enc0
The following command lists attributes for all enclosures in a system:
The following is example output from this command:
Displaying information about array ports
Displaying information about TPD-controlleddevices
Gathering and displaying I/O statistics
To enable the gathering of statistics, enter this command:
To reset the I/O counters to zero, use this command:
memory
32k
Page
Setting the attributes of the paths to an enclosure
Displaying the I/O policy
Specifying the I/O policy
Page
2 up to 2^31 as illustrated in the table below:
Partition size in blocks
Equivalent size in bytes
dmp_pathswitch_blks_shift
# vxdmpadm setattr enclosure enc0 iopolicy=balanced
Page
#vxdmpadm setattr arrayname DISK iopolicy=singleactive
Scheduling I/O on the paths of an Asymmetric Active/Active array
You can specify the
attribute in conjunction with the
(A/A-A)
A/A-A
Page
Disabling I/O for paths, controllers or array ports
Enabling I/O for paths, controllers or array ports
Upgrading disk controller firmware
Renaming an enclosure
156Administering dynamic multipathing (DMP)
Configuring the response to I/O failures
#vxdmpadm getattr
{enclosure enc-name|arrayname name|arraytype type} \ recoveryoption
See “Displaying recoveryoption values” on page 159 for more information
#vxdmpadm getattr enclosure enc0 recoveryoption
Configuring the I/O throttling mechanism
{enclosure enc-name|arrayname name|arraytype type}\ recoveryoption
{enclosure enc-name|arrayname name|arraytype type}\ recoveryoption=nothrottle
158Administering dynamic multipathing (DMP)
#vxdmpadm setattr enclosure enc0 recoveryoption=nothrottle
iotimeout
queuedepth
Note: The iotimeout and queuedepth attributes are mutually exclusive
Displaying recoveryoption values
Recovery option
Possible settings
Description
160Administering dynamic multipathing (DMP)
Configuring DMP path restoration policies
vxdmpadm disable
Use the start restore command to configure one of the following policies:
start restore
■check_all
Stopping the DMP path restoration thread
Displaying the status of the DMP path restoration thread
Displaying information about the DMP error-handlingthread
Configuring array policy modules
Page
Page
Creating and administering disk groups
Page
Specifying a disk group to commands
Rules for determining the default disk group
Displaying the system-wideboot disk group
Displaying and specifying the system-widedefault disk group
Displaying disk group information
Disk: c0t12d0
Creating a disk group
Adding a disk to a disk group
Removing a disk from a disk group
Deporting a disk group
Importing a disk group
Handling disks with duplicated identifiers
udid_mismatch
c2t68d0
Writing a new UDID to a disk
#vxdisk [-f] [-g diskgroup] updateudid disk
#vxdisk updateudid c2t66d0 c2t67d0
Importing a disk group containing cloned disks
option to the vxdg import command, as shown in this
nconfig=all
nlog=all
Sample cases of operations on cloned disks
Enabling configuration database copies on tagged disks
These tags can be viewed by using the vxdisk listtag command:
# vxdisk listtag
t1:
Importing cloned disks without tags
#vxdg -nnewdg -ouseclonedev=on -oupdateid import mydg
online udid_mismatch
To import only the cloned disks into the mydg disk group:
#vxdg -ouseclonedev=on -oupdateid import mydg
EMC0_27
Importing cloned disks with tags
to online clone_disk
#vxdisk set EMC0_8 clone=off
#vxdg -ouseclonedev=on -otag=t1 -oupdateid import mydg
EMC0_15
Renaming a disk group
Moving disks between disk groups
Moving disk groups between systems
Handling errors when importing disks
The following error message indicates a recoverable error
#vxdg -fimport diskgroup
See “Handling conflicting configuration copies” on page
8 (Remove access to (deport) a disk group)
Reserving minor numbers for disk groups
device minor number
base_minor
#vxprint -lmydg | egrep minors minors: >=45000
#vxprint -gmydg -m| egrep base_minor base_minor=45000
#vxdg init diskgroup minor=base_minor disk_access_name
minor=base_minor
#xvdg init newdg minor=30000 c1d0t0 c1t1d0
Compatibility of disk groups between platforms
Handling conflicting configuration copies
Page
192Creating and administering disk groups
in the output from the
command). This case is illustrated below
Example of a serial split brain condition that can be resolved
automatically
Example of a true serial split brain condition that cannot be resolved
imported on host Y
Shared disk group fails to import
Expected A = 1 Expected B
Expected A = 0 Expected B
Correcting conflicting configuration information
vxsplitlines
#vxsplitlines -gnewdg
The following splits were found in disk group newdg
They are listed in da(dm) name pairs
Reorganizing the contents of disk groups
To perform online maintenance and upgrading of
off-host
processing
Disk group move operation
Page
Disk group join operation
self-contained
Limitations of disk group split and join
The disk group split and join feature has the following limitations:
■The reconfiguration must involve an integral number of physical disks
■Objects to be moved must not contain open volumes
■Disks cannot be moved between CDS and non-CDScompatible disk groups
Listing objects potentially affected by a move
#vxdg [-oexpand] listmove sourcedg targetdg object
#vxdg listmove mydg newdg vol1
#vxdg listmove mydg newdg mydg01
#vxdg -oexpand listmove mydg newdg mydg01
Page
202Creating and administering disk groups
Examples of disk groups that can and cannot be split
Volume
data plexes
Split
Page
#vxprint
#vxdg -oexpand move mydg rootdg mydg01
#vxrecover -g targetdg -m[volume ...]
#vxvol -g targetdg startall
Page
The output from vxprint after the split shows the new disk group, mydg:
#vxdg [-ooverride|verify] join sourcedg targetdg
Note: You cannot specify rootdg as the source disk group for a join operation
# vxprint
Disabling a disk group
Destroying a disk group
Upgrading a disk group
Page
Features supported by disk group versions
New features supported
Previous version
features supported
version
To list the version of a disk group, use this command:
#vxdg list dgname
#vxdg upgrade dgname
Managing the configuration daemon in VxVM
Backing up and restoring disk group configuration data
Using vxnotify to monitor configuration changes
Using vxnotify to monitor configuration changes
Creating and administering subdisks
Creating subdisks
Displaying subdisk information
Moving subdisks
Splitting subdisks
Joining subdisks
Associating subdisks with plexes
Associating subdisks with plexes
#vxsd [-g diskgroup] assoc plex subdisk1 [subdisk2 subdisk3 ...]
] assoc
#vxsd -gmydg assoc home-1 mydg02-01 mydg02-00 mydg02-01
#vxsd [-g diskgroup] -l offset assoc sparse_plex exact_size_subdisk
Associating log subdisks
Dissociating subdisks from plexes
Removing subdisks
Changing subdisk attributes
Page
Creating and administering plexes
Creating plexes
Creating a striped plex
Displaying plex information
ACTIVE plex state
CLEAN plex state
DCOSNP plex state
EMPTY plex state
IOFAIL plex state
LOG plex state
OFFLINE plex state
SNAPATT plex state
SNAPTMP plex state
STALE plex state
TEMP plex state
TEMPRM plex state
TEMPRMSD plex state
Plex condition flags
IOFAIL plex condition
NODAREC plex condition
NODEVICE plex condition
Attaching and associating plexes
Taking plexes offline
Detaching plexes
Reattaching plexes
Moving plexes
Copying volumes to plexes
Dissociating and removing plexes
Changing plex attributes
Creating volumes
Types of volume layouts
Supported volume logs and maps
Version 0 DCO volumes only support Persistent FastResync for the traditional
Version 0 DCO volume layout
Version 20 DCO volume layout
Creating a volume with a version 20 DCO volume
Creating a volume
Using vxassist
operation
The vxassist utility helps you perform the following tasks:
■Creating volumes
■Creating mirrors for existing volumes
■Growing or shrinking existing volumes
Setting default values for vxassist
/etc/default/vxassist
/etc/default
#vxassist help showattrs
The following is a sample vxassist defaults file:
Discovering the maximum size of a volume
Disk group alignment constraints on volumes
Creating a volume on any disk
Creating a volume on specific disks
Specifying ordered allocation of storage to volumes
ordered
1Concatenate disks
2Form columns
3Form mirrors
246Creating volumes
Example of using ordered allocation to create a striped-mirror
mydg01-01
mydg03-01
mydg04-01
Example of using concatenated disk space to create a mirrored
mydg04-01
mydg06-01
mydg08-01
Mirrored-stripevolume
Page
Creating a mirrored volume
Creating a volume with a version 0 DCO volume
To upgrade a disk group to version 90, use the following command:
#vxdg -T90 upgrade diskgroup
For more information, see “Upgrading a disk group” on page
layout
\ logtype=dco [ndcomirror
Creating a volume with a version 20 DCO volume
Creating a volume with dirty region logging enabled
Creating a striped volume
254Creating volumes
#vxassist -b -gmydg make stripevol 30g layout=stripe \ mydg03 mydg04 mydg05
#vxassist -b -gmydg make stripevol 30g layout=stripe \ stripeunit=32k ncol=5
Creating a mirrored-stripevolume
A mirrored-stripevolume mirrors several striped data plexes
To create a striped-mirrorvolume, use the following command:
Creating a striped-mirrorvolume
Mirroring across targets, controllers or enclosures
Creating a RAID-5volume
Creating tagged volumes
Creating a volume using vxmake
mydg00-00
mydg03-00
mydg01-00
mydg04-00
Creating a volume using a vxmake description file
#vxmake [-g diskgroup] < description_file
Alternatively, you can specify the file to vxmake using the -d option:
# vxmake [-g diskgroup] -d description_file
Initializing and starting a volume
Initializing and starting a volume created using vxmake
Accessing a volume
Administering volumes
Displaying volume information
Volume states
ACTIVE volume state
CLEAN volume state
EMPTY volume state
INVALID volume state
NEEDSYNC volume state
REPLAY volume state
SYNC volume state
Volume kernel states
Monitoring and controlling tasks
Managing tasks with vxtask
vxtask operations
EXITED
pause Puts a running task in the paused state, causing it to suspend operation
resume Causes a paused task to continue operation
Using the vxtask command
To list all tasks currently running on the system, use the following command:
#vxtask list
#vxtask -hlist
foodg
Stopping a volume
Starting a volume
Adding a mirror to a volume
Adding a mirror to a volume
Mirroring all volumes
#/etc/vx/bin/vxmirror -g diskgroup -a
#/etc/vx/bin/vxmirror -dyes
nmirror=1
nomirror
Removing a mirror
Adding logs and maps to volumes
Preparing a volume for DRL and instant snapshots
Using a DCO and DCO volume with a
Specifying storage for version 20 DCO plexes
disk05
disk06
#vxsnap -gmydg prepare myvol ndcomirs=2 alloc=disk05,disk06
vol1_dco
Using a DCO and DCO volume with a RAID-5volume
Determining the DCO version number
Determining if DRL is enabled on a volume
#vxprint [-g diskgroup] -F%drl$DCONAME
DRL is enabled if this command displays on
#vxprint [-g diskgroup] -F%sequentialdrl$DCONAME
Sequential DRL is enabled if this command displays on
Upgrading existing volumes to use version 20 DCOs
To upgrade a disk group to the latest version, use the following command:
#vxprint [-g diskgroup] -F“%name” -e“v_hasdcolog”
#vxassist [-g diskgroup] remove log volume [nlog=n]
nlog
#vxassist [-g diskgroup] snapback snapvol
Adding traditional DRL logging to a mirrored volume
vol03
#vxassist -gmydg addlog vol03 logtype=drl
logtype=drlseq
#vxassist -gmydg addlog volume logtype=drlseq [nlog=n]
Removing a traditional DRL log
To remove a DRL log, use the vxassist command as follows:
#vxassist [-g diskgroup] remove log volume logtype=drl [nlog=n]
mydg10
# vxassist -gmydg remove log vol01 !mydg10 logtype=drl
Adding a RAID-5log
Resizing a volume
Resizing volumes using vxresize
vxresize
Resizing volumes using vxassist
The following modifiers are used with the vxassist command to resize a volume:
growto Increase volume to a specified length
Extending to a given length
To extend a volume to a specific length, use the following command:
Shrinking to a given length
Shrinking by a given length
Resizing volumes using vxvol
Setting tags on volumes
Changing the read policy for mirrored volumes
Removing a volume
Moving volumes from a VM disk
Moving volumes from a VM disk
To move volumes from a disk
1Select menu item 6 (Move volumes from a disk) from the vxdiskadm main menu
Enabling FastResync on a volume
Checking whether FastResync is enabled on a volume
Disabling FastResync
Performing online relayout
Permitted relayout transformations
Relayout to
From concat
concat
raid5
Supported relayout transformations for RAID-5volumes
From raid5
From mirror-concat
Supported relayout transformations for mirrored-stripevolumes
From mirror-stripe
Supported relayout transformations for unmirrored stripe and
layered striped-mirrorvolumes
From stripe or stripe-mirror
Specifying a non-defaultlayout
ncol
ncol=-number
stripeunit=size
Specifying a plex for relayout
Viewing the status of a relayout
#vxrelayout -gmydg status vol04 might display output similar to this:
See the vxrelayout(1M) manual page for more information about this command
#vxtask monitor myconv
Controlling the progress of a relayout
Converting between layered and non-layeredvolumes
Page
Page
Administering volume snapshots
Page
Traditional third-mirror break-offsnapshots
Page
Full-sizedinstant snapshots
for details of the procedures for creating and using this type of snapshot
Creating a volume for use as a
full-sized
instant or linked
Space-optimizedinstant snapshots
Emulation of third-mirror break-offsnapshots
Linked break-offsnapshot volumes
Cascaded snapshots
Creating a snapshot of a snapshot
Page
Page
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Creating multiple snapshots
Restoring the original volume from a snapshot
Page
Creating instant snapshots
voliomem_maxpool_sz
warning such as the following (for a system whereis set to 12MB):
To make the volumes usable for instant snapshot operations, use
on the volume, and then use
re-prepare
voliomem_maxpool_sz
(in this example, 1MB):
Preparing to create instant and
■“Creating and managing space-optimizedinstant snapshots” on page
■“Creating and managing full-sizedinstant snapshots” on page
Preparing to create instant and break-offsnapshots
To prepare a volume for the creation of instant and break-offsnapshots
#vxprint -g volumedg -F%instant volume
#vxprint -g volumedg -F%fastresync volume
2To prepare a volume for instant snapshots, use the following command:
Creating a shared cache object
To create a shared cache object
Having decided on its characteristics, use the
cachevol
mydg16
Creating a volume for use as a full-sizedinstant or linked break-offsnapshot
#LEN=‘vxprint [-g diskgroup] -F%len volume‘
ksh
bash
csh
Creating and managing space-optimizedinstant snapshots
Creating a shared cache object
To create and manage a space-optimizedinstant snapshot
To create a
snap3myvol
myvol
snap4myvol
mydg15
Use
# fsck -Fvxfs /dev/vx/rdsk/diskgroup/snapshot
You now have the following choices of what to do with a
Creating and managing full-sizedinstant snapshots
To create and manage a full-sizedinstant snapshot
instant snapshot, use the following form of the
snap1myvol
#vxsnap -gmydg make source=myvol/snapvol=snap1myvol
Page
Creating and managing third-mirror break-offsnapshots
To create and manage a third-mirror break-offsnapshot
To create the snapshot, you can either take some of the existing
SNAPATT
# vxsnap -gmydg addmir vol1 nmirror=2 alloc=mydg10,mydg11
330Administering volume snapshots
#vxsnap -gmydg snapwait vol1 nmirror=2
snapshot, use the following form of the
state. (Such plexes could have been added to the volume by using the
command.)
Creating and managing linked break-offsnapshot volumes
To create and manage a linked break-offsnapshot
Use the following command to link the prepared snapshot volume
# vxsnap [-g diskgroup] [-b]addmir volume mirvol=snapvol
[mirdg=snapdg]
snapdg
mysnapdg
#vxsnap -gmydg -baddmir vol1 mirvol=prepsnap \ mirdg=mysnapdg
#vxsnap -gmydg snapwait vol1 mirvol=prepsnap \ mirdg=mysnapvoldg
Creating multiple instant snapshots
snapvol1
snapvol2
Creating a volume for use as a
full-sized
Creating instant snapshots of volume sets
, and
vxvset list
#vxvset -gmydg list vset1
INDEX
nmirrors
vset1
snapvset1
#vxsnap -gmydg prepare vset1
#vxsnap -gmydg prepare snapvset1
Adding snapshot mirrors to a volume
#vxsnap -gmydg addmir vol1 nmirror=2 alloc=mydg10,mydg11
plex
Removing a snapshot mirror
To remove a single snapshot mirror from a volume, use this command:
Removing a linked break-offsnapshot volume
To remove a linked break-offsnapshot volume from a volume, use this command:
mirvol
\ [mirdg
snapvol
Reattaching an instant snapshot
Note: This operation is not supported for space-optimizedinstant snapshots
snapmyvol
#vxsnap -gmydg reattach snapmyvol source=myvol nmirror=1
SNAPTMP
Reattaching a linked break-offsnapshot volume
To reattach a linked
snapshot volume, use the following form of the
sourcedg
snapdiskgroup
Restoring a volume from an instant snapshot
It is not possible to restore a volume from an unrelated volume
snap3myvol
#vxsnap -gmydg restore myvol source=snap3myvol
Dissociating an instant snapshot
Removing an instant snapshot
Splitting an instant snapshot hierarchy
Displaying instant snapshot information
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(1M) manual page for more information about using the
commands
Controlling instant snapshot synchronization
Command
Improving the performance of snapshot synchronization
syncstart
iosize
size
slow
Tuning the autogrow attributes of a cache
attributes determine how the VxVM cache daemon
) maintains the cache if the
feature has been enabled and
is running:
Growing and shrinking a cache
Removing a cache
Creating traditional third-mirror break-offsnapshots
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It is also possible to make a snapshot plex from an existing plex in a volume
See “Converting a plex into a snapshot plex” on page 351 for details
3Create a snapshot volume using the following command:
#vxassist [-g diskgroup] snapshot [nmirror=N] volume snapshot
For example, to create a snapshot of voldef, use the following command:
Converting a plex into a snapshot plex
To convert an existing plex into a snapshot plex for a volume on which
Persistent FastResync is enabled, use the following command:
#vxplex [-g diskgroup] -odcoplex=dcologplex convert \ state=SNAPDONE plex
dcologplex
Creating multiple snapshots
#vxassist [-g diskgroup] snapshot volume1 volume2
] snapshot
reverses the order of the number and volume components in
allvols
Adding plexes to a snapshot volume
Dissociating a snapshot volume
Displaying snapshot information
#vxassist snapprint [volume]
Output from this command is shown in the following examples:
#vxassist -gmydg snapprint
SNAP-v2
Adding a version 0 DCO and DCO volume
3Use the following command to add a DCO and DCO volume to the existing volume:
Specifying storage for version 0 DCO plexes
#vxassist -gmydg addlog myvol logtype=dco dcolen=264 \ mydg05 mydg06
vol1
For more information, see the vxassist(1M) and vxdco(1M) manual pages
Reattaching a version 0 DCO and DCO volume
#vxdco [-g diskgroup] att volume dco_obj
myvol_dco
#vxdco -gmydg att myvol myvol_dco
For more information, see the vxdco(1M) manual page
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Creating and administering volume sets
Creating a volume set
Adding a volume to a volume set
Listing details of volume sets
Stopping and starting volume sets
Removing a volume from a volume set
Raw device node access to component volumes
Raw device node access to component volumes
Note the following limitations of this feature:
■The disk group version must be 120 or greater
Enabling raw device access when creating a volume set
#vxvset [-g diskgroup] -omakedev=on
[-o compvol_access={read-only|read-write}]
[-o index] [-c"ch_addopt"] make vset vol [index]
Displaying the raw device access settings for a volume set
Controlling raw device access for an existing volume set
The syntax for setting the compvol_access attribute on a volume set is:
#vxvset [-g diskgroup] [-f] set
compvol_access={read-only|read-write} vset
The following example sets the
attributes on a volume set
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Configuring off-hostprocessing
Implementing off-hostprocessing solutions
Implementing off-hostonline backup
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On the primary host, if you temporarily suspended updates to a volume in
#vxdg deport snapvoldg
#vxdg import snapvoldg
#vxrecover -g snapvoldg -m snapvol
#vxvol -g snapvoldg start snapvol
Implementing decision support
# vxprint -g volumedg -F%fastresync volume
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You can then resume the procedure from step 6 on page
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Administering hot-relocation
How hot-relocationworks
Finally
Relocation of failing subdisks is not possible in the following cases:
The failing subdisks are on
■There are insufficient spare disks or free disk space in the disk group
The only available space is on a disk that already contains the
Figure 12-1Example of hot-relocationfor a subdisk in a RAID-5volume
mydg02-02 mydg03-02
mydg01 mydg02 mydg03 mydg04 mydg05
Partial disk failure mail messages
for information on how to send the mail to users other than
#vxstat -gmydg -s -ff home-02 src-02
mydg02-03
mydg02-04
Complete disk failure mail messages
How space is chosen for relocation
Configuring a system for hot-relocation
Displaying spare disk information
Marking a disk as a hot-relocationspare
Removing a disk from use as a hot-relocationspare
Excluding a disk from hot-relocationuse
Making a disk available for hot-relocationuse
Configuring hot-relocationto use only spare disks
Moving and unrelocating subdisks
Administering hot-relocation391
Moving and unrelocating subdisks
Volume home Subdisk mydg02-03relocated to mydg05-01,but not yet recovered
Moving and unrelocating subdisks using vxdiskadm
2This option prompts for the original disk media name first
Enter the original disk name [<disk>,list,q,?]
Currently there are no
hot-relocated
Moving and unrelocating subdisks using vxassist
#vxassist -gmydg move home !mydg05 mydg02
!mydg05
Moving and unrelocating subdisks using vxunreloc
The examples in the following sections demonstrate the use of vxunreloc
Moving hot-relocatedsubdisks back to their original disk
mydg01
#vxunreloc -gmydg mydg01
Moving hot-relocatedsubdisks back to a different disk
#vxunreloc -gmydg -nmydg05 mydg01
Examining which subdisks were hot-relocatedfrom a disk
#vxprint -gmydg -se'sd_orig_dmname="mydg01
Restarting vxunreloc after errors
vxunreloc moves subdisks in three phases:
UNRELOC
Modifying the behavior of hot-relocation
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Administering cluster functionality
Overview of cluster volume management
Page
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Private and shared disk groups
Activation modes of shared disk groups
exclusivewrite
Activation modes for shared disk groups
Note: The default activation mode for shared disk groups is off (inactive)
Activation mode
Page
Connectivity policy of shared disk groups
■All nodes in the cluster see exactly the same configuration
■Only the master node can change the configuration
Global detach policy
Local detach policy
for information on how to use the
command to set the disk detach policy on a shared disk group
The table
disk detach policies
Disk group failure policy
Behavior of master node for different failure policies
Leave
Disable
(dgfailpolicy=leave)
Guidelines for choosing detach and failure policies
#vxdg -g diskgroup set diskdetpolicy=local dgfailpolicy=leave
Effect of disk connectivity on cluster reconfiguration
Limitations of shared disk groups
Cluster initialization and configuration
vxclustadm utility
Node abort messages
Reason
Volume reconfiguration
vxconfigd daemon
■master node ID
■role of the node
■network address of the vxconfigd daemon on each node (if applicable)
vxconfigd daemon recovery
If the
#hagrp -freeze group
Use the following command to
# hagrp -unfreeze group
Node shutdown
clean node shutdown
draining
Multiple host failover configurations
Import lock
Failover
Moving disk groups between systems
Corruption of disk group configuration
vxdg import
where the reason can describe errors such as:
for more information on Veritas Volume Manager error messages
Administering VxVM in cluster environments
Determining if a disk is shareable
#vxdisk list accessname
accessname
Listing shared disk groups
Example output from this command is displayed here:
Creating a shared disk group
Note: Shared disk groups can only be created on the master node
#vxdg -sinit diskgroup [diskname=]devicename
init
Importing disk groups as shared
Note: Shared disk groups can only be imported on the master node
#vxdg -simport diskgroup
Forcibly importing a disk group
You can use the -f option to the vxdg command to import a disk group forcibly
Converting a disk group from shared to private
Note: Shared disk groups can only be deported on the master node
Then reimport the disk group on any cluster node using this command:
Changing the activation mode on a shared disk group
Setting the disk detach policy on a shared disk group
Setting the disk group failure policy on a shared disk group
Creating volumes with exclusive open access by a node
Setting exclusive open access to a volume by a node
Displaying the cluster protocol version
Displaying the supported cluster protocol version range
Upgrading the cluster protocol version
Recovering volumes in shared disk groups
Obtaining cluster performance statistics
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Administering
sites and remote mirrors
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Configuring sites for hosts and disks
Configuring site-basedallocation on a disk group
Configuring site consistency on a disk group
Configuring site consistency on a volume
Setting the siteread policy on a volume
Site-basedallocation of storage to volumes
Site-basedallocation of storage to volumes
#vxassist -g diskgroup make volume size mirror=site
a non-site-consistentmirrored volume with plexes at all of the sites:
mirror=site \ allsites=on siteconsistent
off
Examples of storage allocation using sites
nmirror=2
ccdg
ordered
make vol 2g
Making an existing disk group site consistent
Fire drill — testing the configuration
Automatic site reattachment
vxnotify
vxdg detachsite
Failure scenarios and recovery procedures
Recovery from a loss of site connectivity
#vxdg -g diskgroup -ooverridessb reattachsite sitename
Recovery from host failure
Recovery from storage failure
Recovery from site failure
Page
Using Storage Expert
About Storage Expert
How Storage Expert works
Before using Storage Expert
Running Storage Expert
Running Storage Expert
info
Discovering what a rule does
#vxse_stripes2 info
Displaying rule attributes and their default values
mirror_threshold
#vxse_drl1 list
Rule result types
Setting rule attributes
Identifying configuration problems using Storage Expert
Checking for large mirror volumes without a dirty region log (vxse_drl1)
See “Preparing a volume for DRL and instant snapshots” on page
To check whether a large mirrored volume has a mirrored DRL log, run rule
Checking for RAID-5volumes without a RAID-5log (vxse_raid5log1)
To check whether a RAID-5volume has an associated RAID-5log, run rule
Disk groups
Checking whether a configuration database is too full (vxse_dg1)
See “Creating a disk group” on page
Checking disk group configuration copies and logs (vxse_dg2)
Checking “on disk config” size (vxse_dg3)
Checking the number of configuration copies in a disk group (vxse_dg5)
See “Creating and administering disk groups” on page
Checking for non-importeddisk groups (vxse_dg6)
To check for disk groups that are visible to VxVM but not imported, run rule
See “Importing a disk group” on page
Disk striping
Checking the configuration of large mirrored-stripevolumes (vxse_mirstripe)
See “Converting between layered and non-layeredvolumes” on page
Checking the number of columns in RAID-5volumes (vxse_raid5)
To check whether
Checking the number of columns in striped volumes (vxse_stripes2)
Disk sparing and relocation management
Checking the number of spare disks in a disk group (vxse_spares)
Hardware failures
Checking for disk failures and disabled controllers (vxse_dc_failures)
Checking the system name (vxse_host)
Rule definitions and attributes
See “Running a rule” on page
Table 15-2 lists the available rule attributes and their default values
Attribute
Default
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Performance monitoring and tuning
Performance guidelines
Striping
Mirroring
Combining mirroring and striping
RAID-5
Volume read policies
Performance monitoring
Tracing volume operations
Printing volume statistics
VxVM records the following I/O statistics:
■count of operations
■number of blocks transferred (one operation can involve more than one block)
Using performance data
Using I/O statistics
#vxprint -gmydg -tvharchive
The following is an extract from typical output:
#vxassist -gmydg move archive !mydg03 dest_disk
dest_disk
#vxassist -gmydg move archive !mydg03 mydg04
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Tuning VxVM
Tuning guidelines for large systems
Number of configuration copies for a disk group
Changing the values of tunables
Tunable parameters
dmp_cache_open
dmp_daemon_count
dmp_delayq_interval
page 160dmp_failed_io_threshold
dmp_health_time
dmp_health_time
dmp_path_age
dmp_log_level
dmp_path_age
dmp_probe_idle_lun
dmp_queue_depth
dmp_restore_cycles
The value of this tunable is only changeable by using the
dmp_restore_interval
dmp_restore_policy
The DMP restore policy, which can be set to 0 (CHECK_ALL)
(CHECK_DISABLED), 2 (CHECK_PERIODIC), or 3 (CHECK_ALTERNATE)
dmp_retry_count
/kernel/drv/ vxdmp.conf
dmp_stat_interval
vol_checkpt_default
vol_default_iodelay
vol_fmr_logsz
vol_max_vol
vol_maxio
vol_maxioctl
vol_maxparallelio
vol_maxspecialio
vol_subdisk_num
volcvm_smartsync
voldrl_max_drtregs
voldrl_max_seq_dirty
voldrl_min_regionsz
Note: If DRL sequential logging is configured, the value of
voliomem_maxpool_sz
voliot_errbuf_dflt
voliot_iobuf_default
voliot_iobuf_limit
voliot_iobuf_max
voliot_max_open
volpagemod_max_memsz
#vxtune volpagemod_max_memsz value
volraid_minpool_sz
volraid_rsrtransmax
Page
Commands summary
■ “Creating volumes” on page
■ “Administering volumes” on page
■ “Monitoring and controlling tasks” on page
Table A-1
Obtaining information about objects in VxVM
# vxinfo -gmydg myvol1
myvol2
# vxprint -gmydg myvol1
# vxprint -st -gmydg
# vxprint -pt -gmydg
# vxdiskadd c0t1d0
# vxedit -gmydg rename
mydg03 mydg02
# vxedit -gmydg set
reserve=on mydg02
spare=on mydg04
spare=off mydg04
# vxdisk offline c0t1d0
# vxdg -gmydg rmdisk c0t2d0
# vxdiskunsetup c0t3d0
Table A-3
# vxdg init mydg
mydg01=c0t1d0
# vxsplitlines -gmydg
# vxdg -nnewdg deport mydg
# vxdg -oexpand listmove
mydg newdg myvol1
# vxdg -oexpand move mydg
newdg myvol1
# vxdg -oexpand split mydg
# vxrecover -gmydg -sb
# vxdg destroy mydg
Table A-4
# vxmake -gmydg sd
mydg02-01mydg02,0,8000
# vxsd -gmydg assoc
vol01-01 mydg10-01:0
mydg11-01:1 mydg12-01:2
# vxsd -gmydg mv mydg01-01
# vxsd -gmydg -s1000m
# vxunreloc -gmydg mydg01
# vxsd -gmydg -orm dis
Table A-5
# vxmake -gmydg plex
vol01-02
vol01-02
# vxplex -gmydg mv
vol02-02 vol02-03
# vxplex -gmydg cp vol02
vol03-01
vol02-02
Table A-6
# vxassist -gmydg maxsize \ layout=raid5 nlog=2
mysvol 20g layout=stripe
stripeunit=32 ncol=4
# vxmake -gmydg -Uraid5
vol r5vol
plex=raidplex,raidlog1
raidlog2
# vxvol -gmydg start r5vol
Table A-7
#vxassist -gmydg mirror \ myvol mydg10
# vxassist -gmydg remove
mirror myvol !mydg11
# vxassist -gmydg growby
# vxsnap -gmydg prepare \ myvol drl=on
#vxsnap -gmydg make \ source=myvol/\ newvol=mysnpvol/\ nmiror=2
# vxassist -gmydg make
cvol 1g layout=mirror
init=active mydg16 mydg17
# vxmake -gmydg cache cobj
cachevolname=cvol
# vxsnap -gmydg unprepare \ myvol
#vxassist -gmydg relayout \ vol2 layout=stripe
vol3 layout=raid5
stripeunit=16 ncol=4
reverse vol3
#vxassist -gmydg remove \ myvol
Table A-8
# vxrecover -gmydg
-tmytask -bmydg05
# vxtask -h -gmydg list
# vxtask pause mytask
# vxtask -p -gmydg list
# vxtask resume mytask
# vxtask abort mytask
Online manual pages
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Section 4 — file formats
Manual pages in section 4 describe the format of files that are used by Veritas
Volume Manager
Table A-10
Section 4 manual pages
Configuring Veritas
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Glossary
522 Glossary
cluster
A set of hosts (each termed a node) that share a set of disks
cluster manager
cluster-shareabledisk group
Glossary
log subdisk
disabled path
An alternative term for a device name
disk access records
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Index
