This is the process i have used for logical volume mirrored disk, with success
Replacing SSA disk after it has failed
Basic Overview
1. identify the disk and the resources that use it
2. remove this disk from any volume groups safely so it is not used anywhere ( this may also mean removing other disks from the configuration aswell )
3. isolate the disk within the SSA loop
4. remove the disk definitions
5. remove and replace the disk
6. configure the new disk onto the rs6000 this should have the same pdisk and hdisk as the old disk
7. add to the volume group
8. add to logical volumes and re-mirror and sync volumes
Procedure
1. Check which disk and what it is allocated to it
Normally you have the pdisk number :
Translate pdisk/hdisk ssaxlate –l pdisknnn
Find out volume group lspv | grep hdisknnn
List logical volumes lspv hdisknnn –l
List disks in logical volume lslv lvname –l
List ppartition mapping lslv lvname –m | pg or lslv lvname -m > filename
You also need to know the physical location .. a serial number is useful as the disks have these on the front .. if you have a disk mapping document you maybe able to locate the tray and location from this or use either of the following
diag -- enter -- task selection -- SSA service aids --
link verfication and the the ssa card select the pdisk and hit enter to set identify and note serial number or set service mode find the pdisk set the service mode and note the serial number
maymap -a -h this will report on all SSA loops and what is on it with the hdisk number and serial numbers
If this is part of a HACMP sysytem or where this disk is connected to multiple systems you need to check the other systems, is the disk in use ... what are the pdisk and hdisk names for it ... use the pvid number to track the disk between systems
2. remove disk from logical volume
run rmlvcopy for each logical volume allocated to that disk and remove all disks for that mirror copy
3. remove disk from volume group
run reducevg command for failed disk on the volume group
4. run diag
use ssa service aids ….. set service mode to identify the pdisk this will cause the LED onthe front to flash and isolate the disk in the loop ready for hot swap
5. physically replace disk, then reset service aids to ensure service mode is off
6. remove definition of pdisk and hdisk from box and odm
rmdev-dl hdisknnn
rmdev –dl pdisknnn
7. Now configure new disk
cfgmgr
8. Check new disk hdisk number ( hopefully the same as before ) lspv | grep None
9. add to volume group
extendvg vgname hdisknnn
10. now re make logical volume copies
use mklvcopy add 1 more copy to all disk as before for all logical volumes needed( this sometimes can be complex if a disk is allocated to more than one logical volume then a map
file can be used to ensure that the partition mappings across disk mirrors are correct, )
The allocation map file contains records specifying the exact physical partitions to allocate to the logical volume. Records are in the form: PVname
Pnum1[-PPnum2], where PVname is the physical volume name and PPnum is the physical partition number. Use one record for each physical partition or each range of consecutive physical partitions.
Partitions are used in the order given in the MapFile. Used partitions are skipped.
11. sync logical volumes
syncvg –l lvname
Note : once the logical volume copies are reduced to 1 until the syncvg commands have finished you have no mirroring, if a logical volume uses more that 2 disks in its mirror you increase the risk of data loss through another disk failure once you remove all the mirror disks from a logical volume.
