Configuration: Device Mapper Multipath for Linux 183
NOTE: To ensure data integrity protection, reboot a Linux host server attached to
an MD3200i Series storage array using the procedure given below.
Linux Host Server Reboot Best Practices
Its is recommended that you follow the procedures shown below when
rebooting your Linux host server using Device Mapper multipathing with an
MD3200i Series storage array.
1
Unmount all Device Mapper multipath device nodes mounted on the
server
# umount <mounted_multipath_device_node>
2
Stop the Device Mapper multipath service
# /etc/init.d/multipathd stop
3
Flush the Device Mapper multipath maps list to remove any old or
modified mappings
# multipath –F
NOTE: The boot operating system drive may have an entry with the Device
Mapper multipathing table. This is not affected by the multipath –F
command. However, using #multipath –ll should not show any
multipathing devices with model “MD3200i” or “MD3200i”.
4
Log out of all iSCSI sessions from the host server to the storage array
# iscsiadm –m node --logout
Important Information About Special Partitions
When using Device Mapper with the MD3200i Series array, all physical disks
are assigned a disk device node. This includes a special device type used for
in-band management of the MD3200i Series array, known as the Access Disk
or Universal Xport device.
CAUTION: Certain commands, such as lsscsi, displays one or more instances of
Universal Xport devices. These device nodes must never be accessed, mounted, or
used in any way. Doing so could cause loss of communication to the storage array
and possibly cause serious damage to the storage array, potential making data
stored on the array inaccessible.
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