moving san data

[jthrumston]

I have an HP 11.i box on my EMC san. I want to move the data from 1 VG (3 small luns) to a new VG (1 large lun).
I looked for migratevg but it doesn't appear to be on my box so I thought I would use CP. Once I have the data moved I would just mount the new VG/filesystem.
Is there another or easier way to do this. I only have about 4g+ of data to move.

[Rita C Workman]

There are alot of ways to do this. Yours is easier because your just moving data.

You can create a new volume group and just copy the data.
You can createa a new volume group and restore the data from tape (presuming you backed up to tape).

Here's some advice Jim Ferguson gave me when I had to migrate alot of data. The fbackup option. I found it worked exceedingly well for us.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=51818&admit=-682735245+1175102216284+28353475

Rgrds,
Rita

[James R. Ferguson · Accepted solution]

Hi:

You can move the data in various ways. Using 'cpio', 'tar', 'cp' or 'fbackup' are all ways to perform this. With 'fbackup' you can handle largefiles and preserve permissions together with modification and lastaccess timestamps:

# cd srcdir && fbackup -i . -f - | ( cd dstdir && frecover -Xrf - )

If you elect to use 'cp', make sure that your destination is empty when you begin.

Regards!

...JRF...

[Steven E. Protter]

Shalom,

When possible, I like to shut databases and use san features like snapshots to do migrations.

SAN's are really good at that, but some of those features require a license.

I always back up first and if the SAN feature is unavailable, I go the old fashioned way, using an Ultrium tape and fbackup, like JRF.

SEP

[jthrumston]

thank you for all the help, the fbackup sounds like it will do it, unfortunately I think I found a snag.

if my current filesystem (the fragged one) is named (example) /a and I need the new one (the contiguous one) to also be /a I obviously can't have /a mounted 2 times.
The data in this filesystem is the heart of the application that runs on that box. I am worried about messing it up (and yes I do have backups to restore from but would like to prevent the additional downtime to restore.)
There must be a simple way to do this but I can't get my hands around it right now.

[A. Clay Stephenson]

Of course you can't have two identically mounted filesyetms. You will need to down the application, temporarily mount the new filesystem as something like /a2 and then copy the data from /a to /a2. Next, umount /a, umount /a2, and then alter your /etc/fstab entry so that the the existing /a mounts the new VG/LVOL. Now restart the application. If all is well, you can then vgexport the old VG and rmdir /a2.

[James R. Ferguson]

Hi (again):

> if my current filesystem (the fragged one) is named (example) /a and I need the new one (the contiguous one) to also be /a I obviously can't have /a mounted 2 times.

This isn't a problem. Name (e.g. '/new') and mount your new destination filesystem whatever you choose. Now perform the copy as I suggested in my first post. When done, unmount both the old and the new filesystems. Rename the original mountpoint something like '/old' and rename the "new" one to '/a'. Edit your '/etc/fstab' appropriately so that the underlying devices reflect where you want '/a' to be and issue a 'mount -a' to mount everything.

Remember, when you perform your copy, make sure that neither filesystem is in use!

Regards!

...JRF...