Voting file relocate in 11GR2


Oracle new feature in 11GR2 is that the voting files can reside in a Oracle ASM Diskgroup. The voting files resides in the first sectors of  a disk in every failgroup, so in external redundancy you have only one voting file in a normal redundancy diskgroup you have by default 3 voting disks and so on. Oracle 11GR2 has a new feature which relocate a Voting Disk to a surriving failgroup if one failgroup fails in a diskgroup.

Example:

Our Diskgroup configuration show DG_CLUSTER (group_number=1) with 4 disk and 4 failgroups.

  1* select path,failgroup from v$asm_disk where group_number=1

PATH        FAILGROUP
--------------- ------------------------------
/dev/raw/raw4    DG_CLUSTER_0003
/dev/raw/raw3    DG_CLUSTER_0002
/dev/raw/raw2    DG_CLUSTER_0001
/dev/raw/raw1    DG_CLUSTER_0000

Voting files in DG_CLUSTER Diskgroup:

[root@vmsvrocm01 grid1]# crsctl query css votedisk
##  STATE    File Universal Id                File Name Disk group
--  -----    -----------------                --------- ---------
 1. ONLINE   87b9f3b00a524fb5bfd2a50db8c0243d (/dev/raw/raw1) [DG_CLUSTER]
 2. ONLINE   1fbf883a59cc4f04bfa4ceddb0f1f89f (/dev/raw/raw2) [DG_CLUSTER]
 3. ONLINE   84bd6387e5154fdfbf4c4ff98bf5f107 (/dev/raw/raw3) [DG_CLUSTER]

If one disk (failgroup) fails than the voting file is relocated. So we set the disk /dev/raw/raw1 offline. In my testcase i have done this with  a dd command on OS level.

Output from ASM alert log. You can see that the disk wents offline and a relocate was done.

Thu Apr 11 23:19:24 2013
GMON updating disk modes for group 1 at 5 for pid 27, osid 23745
NOTE: group DG_CLUSTER: updated PST location: disk 0001 (PST copy 0)
NOTE: group DG_CLUSTER: updated PST location: disk 0002 (PST copy 1)
NOTE: group DG_CLUSTER: updated PST location: disk 0003 (PST copy 2)
NOTE: PST update grp = 1 completed successfully
NOTE: initiating PST update: grp = 1, dsk = 0/0xec4735e1, mask = 0x7e, op = clear
GMON updating disk modes for group 1 at 6 for pid 27, osid 23745
NOTE: cache closing disk 0 of grp 1: DG_CLUSTER_0000
NOTE: PST update grp = 1 completed successfully
NOTE: starting check of diskgroup DG_CLUSTER
WARNING: disk DG_CLUSTER_0000 (0) cannot be checked because it is offline
GMON checking disk 1 for group 1 at 7 for pid 27, osid 23745
NOTE: cache closing disk 0 of grp 1: (not open) DG_CLUSTER_0000
GMON checking disk 2 for group 1 at 8 for pid 27, osid 23745
NOTE: cache closing disk 0 of grp 1: (not open) DG_CLUSTER_0000
GMON checking disk 3 for group 1 at 9 for pid 27, osid 23745
NOTE: cache closing disk 0 of grp 1: (not open) DG_CLUSTER_0000
SUCCESS: check of diskgroup DG_CLUSTER found no errors
SUCCESS: alter diskgroup dg_cluster check
Thu Apr 11 23:19:25 2013
NOTE: Attempting voting file refresh on diskgroup DG_CLUSTER
NOTE: Voting file relocation is required in diskgroup DG_CLUSTER
NOTE: Attempting voting file relocation on diskgroup DG_CLUSTER
NOTE: voting file allocation on grp 1 disk DG_CLUSTER_0003
NOTE: Attempting voting file refresh on diskgroup DG_CLUSTER

New voting file configuration after relocate. Cluster remains online if all works well.

[root@vmsvrocm01 trace]# crsctl query css votedisk
##  STATE    File Universal Id                File Name Disk group
--  -----    -----------------                --------- ---------
 1. ONLINE   1fbf883a59cc4f04bfa4ceddb0f1f89f (/dev/raw/raw2) [DG_CLUSTER]
 2. ONLINE   84bd6387e5154fdfbf4c4ff98bf5f107 (/dev/raw/raw3) [DG_CLUSTER]
 3. ONLINE   1e27f91f89de4f52bf4331dec745c4ca (/dev/raw/raw4) [DG_CLUSTER]

If you like it, leave me a comment.

Advertisements

Kommentar verfassen

Trage deine Daten unten ein oder klicke ein Icon um dich einzuloggen:

WordPress.com-Logo

Du kommentierst mit Deinem WordPress.com-Konto. Abmelden / Ändern )

Twitter-Bild

Du kommentierst mit Deinem Twitter-Konto. Abmelden / Ändern )

Facebook-Foto

Du kommentierst mit Deinem Facebook-Konto. Abmelden / Ändern )

Google+ Foto

Du kommentierst mit Deinem Google+-Konto. Abmelden / Ändern )

Verbinde mit %s