[Veritas-vx] Mirroring issue, while using multiple disks coming from different location

[Mohd Aslam]

Hi,
 
I am having a 33GB mirror volume data01, which is created from disk01/disk02. Plex data01-01 is created from disk01, while Plex data01-02 is created from disk02.Both disks are of 33GB only.
 
Now I want to extend this volume by 50GB in such a way that plex-01 will be extended by disk03 while plex02 will be extended by disk04..
 
My problem is that storage team has allocated disk03/04 of 100GB.
 
To acheive this result, I have done
 
# vxplex -g datadg -o rm dis data01-02
# vxresize -F vxfs -x -g datadg data01 +50g disk03
# vxassist -g datadg -b mirror data01 disk02 disk04 --> My problem is with this command.
If I am running the above mentioned command to mirror the volume. It's using only disk04 to mirror data01 volume, since total volume size after resize is 83GB, while disk04 is 100GB. vxassist will put whole volume in a single lun. For some reason I want plex data01-02 to use 33GB from disk01 while 50GB from disk04.
 
Is there some way I can define that while mirroring, plex data01-02 used 33GB space from disk02 and rest 50GB space from disk04.
 
Thanks
Aslam
 

[William Havey]

The 50GB/100GB issue is a non-issue. Specifying a new size for the volume
(and thus for each plex) will restrict VM to extending the length of the
plex by that amount. The remaining 67GB can be used for DRL, DCO, snapshots,
defrags, etc.

I am not certain because of the wording but I understand the statement about
plex sizes to read you require different sized plexes. If this is the case,
it is not possible with VM.

Disk tags and site awareness were added to VM in the 5.x product line to
take account of just such a situation as you describe.

Do not disassociate any plex. Start over after reading up on tags and site
awareness.

Bill

Post by Mohd Aslam
Hi,
I am having a 33GB mirror volume data01, which is created from
disk01/disk02. Plex data01-01 is created from disk01, while Plex data01-02
is created from disk02.Both disks are of 33GB only.
Now I want to extend this volume by 50GB in such a way that plex-01 will be
extended by disk03 while plex02 will be extended by disk04..
My problem is that storage team has allocated disk03/04 of 100GB.
To acheive this result, I have done
# vxplex -g datadg -o rm dis data01-02
# vxresize -F vxfs -x -g datadg data01 +50g disk03
# vxassist -g datadg -b mirror data01 disk02 disk04 *--> My problem is
with this command.*
If I am running the above mentioned command to mirror the volume. It's
using only disk04 to mirror data01 volume, since total volume size after
resize is 83GB, while disk04 is 100GB. vxassist will put whole volume in a
single lun. For some reason I want plex data01-02 to use 33GB from disk01
while 50GB from disk04.
Is there some way I can define that while mirroring, plex data01-02 used
33GB space from disk02 and rest 50GB space from disk04.
Thanks
Aslam
_______________________________________________
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-vx

[A Darren Dunham]

Post by Mohd Aslam
Is there some way I can define that while mirroring, plex data01-02
used 33GB space from disk02 and rest 50GB space from disk04.
# vxplex -g datadg -o rm dis data01-02
# vxresize -F vxfs -x -g datadg data01 +50g disk03
# vxassist -g datadg -b mirror data01 disk02 disk04 --> My problem is with this command.

I would have suggested:
vxresize -F Vxfs -x -g datadg data01 +50g disk03 disk04

Since the volume is a mirror at that point, it will extend onto the two
new disks in a mirrored fashion.

Given where you are now, I don't know of a way for 'vxassist' or 'vxresize'
to mirror in the way you want. You could either remove the extra size,
go back to the single disk, remirror on disk02 and then extend.

Or you could set up a new plex on the new disks and then attach that to
the volume. Maybe something like:

vxassist -g datadg tempvol 33g disk03
vxassist -g datadg growby tempvol 50g disk04 # one plex on tempvol
vxplex -f -g datadg dis <plex>

You can then destroy the temp volume and attach the plex to the original
volume. I don't like doing it this way because getting the sizes to
match up exactly is difficult.