data migration within EMC DMX

[Srini Penumuchu]

Hi folks,
The previous SA on my N class server had used pvmove to move old EMC frame to newer DMX frame and since the new LUN size is 47G( 14 gig larger than old one), the LVM is not seeing the additional disk space because of max pes. So, my task is to reclaim this space and here are my thoughts.

1) Create new volume group and copy the data from old vg to new vg and alter the mount points to reflect the new volume groups.

2) Take the backup via BCV, destroy the volume groups and recreate them with larger PE size and restore from BCV to original disks.

I would really welcome your thoughts on this.

Thanks,
Lambu

[Pete Randall]

Lambu,

Sounds like a reasonable approach to me. You can't really accomplish this with MirrorDisk/UX or pvmove because the new location would have to be within the same Volume Group, so some sort of backup/restore is your only hope. I would suggest doing a backup to tape just in case something goes wrong along the way.


Pete

[Stuart Abramson_2]

Your plan is good, as long as you mean COPY the data with unix commands from BCV to STD. You don't really mean BCV reverse synch, because that means you would put back the old structure on the STD.

This is one of the problems with "pvmove".

BTW, outage will be required.

BTW, why did you make the LUN size so big? You had big LUNs before at 33 GB?

[Srini Penumuchu]

Stuart,
How would reverse sync would fail to achive my goal since when I create a new vg,
it will be seeing the all of the LUNs.

BTW, the LUN sizes were already created before I got this project.

what is the fastest way to accomplish this with reduced downtime?

[Geoff Wild]

We went through the same thing - moving from 8.5 GB hypers to 33GB Metas from 8730 to DMX1000.

I hope you mean "copy" from bcv?

You don't even need to do that - you could just "copy" from standard to standard.

One of the ways we copied was by using vxdump/vxrestore to copy:

vxdump -0 -f - -s 1000000 -b 16 /export/data/ARCHIVE | (cd /zmnt/export/data/ARCHIVE ;
vxrestore rf -)


Rgds...Geoff

[Geoff Wild]

You can only do a symmir restore from equal size bcv's.

Rgds...Geoff

[Rita C Workman]

Lambu,

Wish I could give you the exact url address here..but I am unable to retrieve on Search (it's a boring story...arghgh)

Anyway, try doing a Search for "migrate data" and look for a thread I did awhile back when I had to migrate data to new array. JRF gave me some very sound direction using fbackup/frestore. And this is the approach I would suggest you take.

Now for your BCV's...you may want to use them a backup (just in case). But I wouldn't recommend using them to restore from when you set up your new disks. I recommend you follow the scenario I went through. It took awhile, but it went beautifully.
And again about your BCV's...remember they have to be the exact same size as your Std or R1/R2 disks they are associated with. With this change, what impact will this have on your BCV's????????????????? Will you need to change them once you have your data migrated to your primary disks????

Just a couple thoughts, Sorry I can't post the url...
Rgrds,
Rita

[Srini Penumuchu]

All our vgs are on new dmx and main task is to reclaim the space that got lost due to max pe's limitation (vgcreate's default value). If I sync primary vgs to BCV in additon to taking tape backup then recreate the vg with large pe size, can I able to reverse split from BCV to Primary VG?

Please clarify!

Thanks,
Lambu