2 node VCS RHEL5; VCS resource LVMVolumeGroup does not offline-online properly between nodes

Article:TECH146404  |  Created: 2010-12-16  |  Updated: 2010-12-28  |  Article URL http://www.symantec.com/docs/TECH146404
Article Type
Technical Solution


Issue



---New VCS cluster build where LVM and native Linux LUN Multipathing are not operating properly


Error



---system logs on nodes

sd 5:0:0:5: reservation conflict
sd 5:0:0:6: reservation conflict
sd 5:0:0:7: reservation conflict
sd 5:0:0:8: reservation conflict


Environment



2 node Linux RHEL5 VCS failover cluster

[root@dal-imndbn03 ~]# uname -m
x86_64
[root@dal-imndbn03 ~]# uname -r
2.6.18-128.el5


[root@dal-imndbn03 ~]# rpm -aq | egrep -i 'VRTSvxvm|VRTSvxfs|VRTSllt|VRTSgab|emc'
VRTSgab-5.0.40.00-MP4_RHEL5
VRTSllt-5.0.40.00-MP4_RHEL5

 


[root@dal-imndbn03 ~]# gabconfig -a
GAB Port Memberships
===============================================================
Port a gen   add101 membership 01
Port h gen   add104 membership 01
 

 


Cause



Configuration of Linux RHEL5 LVM and native Multi-pathing is not supported by VCS.

LVM VCS failover requires three VCS resource agents:  LVMVolumeGroup, LVMLogicalVolume and DiskReservation.

LVM currently does not operate with SAN multi-path LUNs.

LVMVolumeGroup agent requires the DiskReservation agent to manage LUNs with single paths only.

 

From the VCS 5.1 Bundled Agent Reference Guide:

 
 
The DiskReservation agent does not reserve disks
that have multiple paths
You cannot use the DiskReservation agent to reserve disks that have multiple
paths. The LVMVolumeGroup and the LVMLogicalVolume agents can only be
used with the DiskReservation agent, Symantec does not support the
configuration of logical volumes on disks that have multiple paths. To ensure
data protection on such a configuration, Symantec recommends the use of
Veritas Volume Manager (VxVM) disk groups. Note that VxVM requires the use
of SCSI-3 compliant disks.

 

 

 


Solution



If SAN LUN multipathing is a requirement for the VCS cluster, the recommedation is to migrate LVM data to  VxVM 5.1 with its bundled DMP multipathing or use other VxVM compatible third party (TPD)  multipathing software (e.g. EMC PowerPath).  




Article URL http://www.symantec.com/docs/TECH146404


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