HP 3PAR Citrix Implementation Guide

8 Modifying HP 3PAR Devices on the Host
Displaying Detailed Device Mapper Node Information
Use Citrix XenServer or the command line interface provided by Citrix to obtain node information.
If applicable, use the sg3_utils packaged with the Citrix installation to collect details.
NOTE: In the following examples, multipath and dmsetup usage provides information only;
do not use these commands to change the node setting.
Use multipath -l for listing of devices and dmsetup to get detailed dm node information.
Example:
# multipath -l
350002ac001b40031
[size=5 GB][features="1 queue_if_no_path"][hwhandler="0"]
\_ round-robin 0 [active]
\_ 0:0:0:0 sda 8:0 [active][undef]
\_ 1:0:0:0 sdb 8:16 [active][undef]
NOTE: If you see the device status as [undef] in the output, this is a Device Mapper defect.
Instead, use the multipath -ll command, which shows the correct device status as ready.
The dmsetup command can be used with various options to get more information on device
mapper mappings.
Example:
# dmsetup table
350002ac001b40031: 0 10485760 multipath 1 queue_if_no_path 0 1 1 round-robin 0 2 1
8:0 100 8:16 100
# dmsetup ls --target multipath
350002ac0004b0079 (253, 7)
# dmsetup info 350002ac0004b0079
Name: 350002ac0004b0079
State: ACTIVE
Read Ahead: 256
Tables present: LIVE
Open count: 1
Event number: 0
Major, minor: 253, 7
Number of targets: 1
UUID: mpath-350002ac0004b0079
# dmsetup table --target multipath
350002ac0004b0079: 0 10485760 multipath 1 queue_if_no_path 0 1 1 round-robin 0 2 1
8:32 100 8:48 100
Removing a Storage Volume from the Host
Use one of the following methods to remove a storage volume from the host if using device mapper.
Displaying Detailed Device Mapper Node Information 39