serviceguard mirror

[juan ramos_1]

Hi all
I have a cluster with a volume group with one disk and its mirror disk, I want to replace one of the disk on the volume group that is reporting error to the syslog, I want to know if I can replace the disk while the cluster is up.
Thanks for any Tips.

[Geoff Wild]

Sure - of course you can - for the most part:

1) If the disk is completely "dead", such as if you run ioscan and status is "no_hw" then you can hot swap the disk online.

2) However in circumstances where the disk has not fully failed please do one of the following to avoid data corruption :

a) reduce mirror before replacing the disk
b) deactivate VG before replacing the disk
c) shutdown system to replace the disk

Rgds...Geoff

[Sundar_7]

Juan,

You can replace the disk as long as the disk is hot swappable.

1) Hot swap the failed disk
2) do a ioscan and confirm the system is able to see the disk with HW STATUS as CLAIMED
3) do a vgcfgrestore and restore the LVM conf to the new disk

# vgcfgrestore -n /dev/vgname /dev/rdsk/cXtYdZ
# vgsync /dev/vgname


- Sundar

[Prashant Zanwar_4]

Hot swapping is meant to be for that purpose or if have internal array mirroed disk then also you shall be able to replace without disturbing anything.

if it is lvmmirrored, do as sundar has said.

Thanks

Prashant

[juan ramos_1]

Thanks all for the responses.
the disk is accesible, sometimes it reports error to the syslog, I want to replace it before it definitely crash.The disk enclousure is hotswap, tell me if I can use this procedure with the package running :

lvreduce -m 0 /dev/vg01/lvol1
vgreduce /dev/vg01 /dev/dsk/c4t0d0
replace the disk (c4t0d0)
pvcreate /dev/rdsk/c4t0d0
vgextend /dev/vg01 /dev/dsk/c4t0d0
lvextend -m 1 /dev/vg01/lvol1 /dev/dsk/c4t0d0

[Geoff Wild]

Actually, you can do a vgcfgrestore:

vgcfgrestore -n /dev/vg01 /dev/rdsk/c4t0d0

vgsync /dev/vg01

Rgds...Geoff

[Sridhar Bhaskarla]

Hi Juan,

There is a simple process for that.

1. Replace the disk. Run ioscan -f and make sure the disk is claimed on both the nodes.
2. Do a 'vgcfgrestore'

vgcfgresotre -n vgxx /dev/rdsk/cxtydz
vgchange -a e vgxx (or use the activation mode you use in serviceguard)

3. vgsync vgxx

That should sync up the mirrors.

-Sri

[PC_7]

you might want to look at technical knowledge base doc id UMCSGKBRC00008685 (attached).

Hope this helps.

[Sandeep Kapare]

The configuration details for a given VG are asored in /etc/lvmconf/VG??.conf file. If you are planning to remove the defective disk out of the volume group (i.e. you are not going to replace it with a good one) only then you need to do vgreduce. Else, the process is preety simple as mentioned by others -
Swap the disk with a good one.
Do ioscan -fnCdisk (& make sure new disk is seen)
do a vgcfgrestore & vgsync.
Your volume is back to its original state.