The VxFS filesystem delicache_enable tunable is not persistent in CFS environment.
Article ID: 100013486
Updated On:
Description
Error Message
Tunefstab created on all systems with required attribute/value
# cat /etc/vx/tunefstab
/dev/vx/dsk/oradatadg/oradatavol delicache_enable=0
Post boot/fs mount, the value is set only on CFS Primary and not no Secondary nodes.
[root@rhel63-01 ~]# vxtunefs /oradata |grep delicache_enable
delicache_enable = 0
[root@rhel63-02 ~]# vxtunefs /oradata |grep delicache_enable
delicache_enable = 1 <<< Secondary still shows old value
On secondary nodes requires vxtunefs to be manually executed after mount to set this tunable.
[root@rhel63-02 ~]# vxtunefs -f /etc/vx/tunefstab
UX:vxfs vxtunefs: INFO: V-3-22525: Parameters successfully set for /oradata
[root@rhel63-02 ~]# vxtunefs /oradata |grep delicache_enable
delicache_enable = 0 <<< New value set on Secondary
Cause
On secondary nodes, we don't read in the tunefstab file as the tunable values are exported from the primary mount. The delicache_enable tunable value is not exported from primary, which causes tunable values not persistent.
Resolution
A supported hotfix has been made available for this issue. Please contact Veritas Technical Support to obtain this fix. This hotfix has not yet gone through any extensive Q&A testing. Consequently, if you are not adversely affected by this problem and have a satisfactory temporary workaround in place, we recommend that you wait for the public release of this hotfix.
Veritas Technologies LLC currently plans to address this issue by way of a patch or hotfix to the current version of the software. Please note that Veritas Technologies LLC reserves the right to remove any fix from the targeted release if it does not pass quality assurance tests. Veritas’ plans are subject to change and any action taken by you based on the above information or your reliance upon the above information is made at your own risk.
WORKAROUND (if unable to install patch):
Manually run vxtunefs on the secondary nodes once the filesystems have been mounted
vxtunefs -f /etc/vx/tunefstab
or
vxtunefs -o delicache_enable=0 /$MNT
example:
# vxtunefs -f /etc/vx/tunefstab
UX:vxfs vxtunefs: INFO: V-3-22525: Parameters successfully set for /oradata
# vxtunefs /oradata |grep delicache_enable
delicache_enable = 0
Applies To
SFCFS 6.0.1 / 6.0.3 / 6.0.5
Issue/Introduction
0 Disables delicache optimization
1 Enables delicache optimization The default value of delicache_enable is 1. However, the performance benefits in case of cluster file system are limited as compared to local mount. In case of CFS, unlike other CFS tunables, we explicitly need to turn this tunable on or off on each and every node in the cluster.
Additional Information
