topic Re: Moving Data between servers in Operating System - HP-UX

Moving Data between servers

MTSU_SAN — Wed, 14 Dec 2005 12:45:28 GMT

I'm replacing an existing production server with a new one. I need to quickly move the data from the existing server to the new one--the bright idea was to mirror the data from the existing server's fc60 disk array to a VA7410 which is attached to both servers.

This is great, but I am having trouble getting the LVM commands to separate out those new mirror disks, without losing the data on them, and then import them as a new VG on the new server.

Any suggestions?
c*

Re: Moving Data between servers

Geoff Wild — Wed, 14 Dec 2005 12:59:01 GMT

What kind of trouble?

You will need to lvreduce -m 0 /dev/vgXX/ /dev/dsk/

When done for all lvols, you need to vgreduce those devs from the vg...

Then vgimport on the new server...

Rgds...Geoff

Re: Moving Data between servers

Rick Garland — Wed, 14 Dec 2005 13:01:28 GMT

Doing a mirror from 1 type of array to another type of array does not always work.

Can copy the data from 1 system to other. Here are some examples using tar, cpio, and vxdump...

to WRITE a tar file TO a remote device
tar cvf - * | remsh (systemname) dd of=/dev/rmt/0m

to LIST (table of contents) tar file ON remote tape device
remsh (systemname) dd if=/dev/rmt/0m | tar tvf -

to READ (get) tar file(s) FROM remote tape device
remsh (systemname) dd if=/dev/rmt/0m | tar xvf -

Do not cross NFS mounts or it will fail.

Remote CPIO

find filesys -print | cpio -ocv | remsh remotehost "dd of=/dev/rmt/0m"

find filesys -print | cpio -ocv | remsh remotehost "dd of=/backup/system_a.cpio"

find . | cpio -oc | remsh remotehost "cd /newpath ; cpio -icdmuv"

/usr/sbin/vxdump 0f - /dev/vg00/osymmgr | remsh luna '(cd /apps/osymmgr; /usr/sbin/vxrestore -rf -)'
/usr/sbin/vxdump 0f - /dev/vg00/openv | remsh luna '(cd /apps/openv; /usr/sbin/vxrestore -rf -)'
/usr/sbin/vxdump 0f - /dev/vgfin107/orahome | remsh luna '(cd /apps/aporacle107; /usr/sbin/vxrestore -rf -)'
/usr/sbin/vxdump 0f - /dev/vgfin107/appsmgr | remsh luna '(cd /apps/appsmgr107; /usr/sbin/vxrestore -rf -)'
/usr/sbin/vxdump 0f - /dev/vgfin107/custom | remsh luna '(cd /apps/custom107; /usr/sbin/vxrestore -rf -)'
/usr/sbin/vxdump 0f - /dev/vgfin107/orchid | remsh luna '(cd /apps/orchid107; /usr/sbin/vxrestore -rf -)'
/usr/sbin/vxdump 0f - /dev/vgcrcard/crcard | remsh luna '(cd /apps/crcard107; /usr/sbin/vxrestore -rf -)'

Re: Moving Data between servers

James R. Ferguson — Wed, 14 Dec 2005 13:06:34 GMT

Hi Connie:

If you are merely replacing the server, then 'vgexport' your non-vg00 volume groups and 'vgimport' them on the new server. This is one of the things that 'vgexport/vgimport' is designed to do.

# vchange -a n vgNN
# vgexport -m /tmp/vgNN.map -v -f /tmp/vgNN.dev vgNN

...move '/tmp/vgNN.map' and '/tmp/vgNN.dev' to new server; edit the device file paths in '/tmp/vgNN.dev' to match the new server's configuration; and 'vgimport':

...OR, use th e'-s' variation of 'vgexport':

# vgexport -m /tmp/vgNN.map -s -v vgNN

...and on the new server (either):

# vgimport -m /tmp/vgNN.map -v -f /tmp/vgNN.dev vgNN

(or):

# vgimport -m /tmp/vgNN.map -s -v vgNN

# vgchange -a y

Regards!

...JRF...

Re: Moving Data between servers

Chan 007 — Wed, 14 Dec 2005 13:31:55 GMT

Hi,

I use the method of JRF..

lvreduce to remove mirror.

Ensure that your application and database is down while removing the mirror to have a complete sync.

Cheers ...007

Re: Moving Data between servers

MTSU_SAN — Wed, 14 Dec 2005 13:53:55 GMT

Appreciate all of the replies, but I need some time where both servers are up for testing before the change--the cpio is fine, but will take days (I've done this before when I installed Service Guard cluster), and the vgexport will give me no time to test.
c*

Re: Moving Data between servers

MTSU_SAN — Wed, 14 Dec 2005 13:56:30 GMT

Oh, and Geoff, I did that and the new server complained that the disks belonged to another CPU ID, and the data was not retrievable on those disks.
c*

Re: Moving Data between servers

Robert-Jan Goossens — Wed, 14 Dec 2005 14:17:11 GMT

Connie,

Title: Moving disks from Server1 to Server2
Document ID: KBRC00014628

US
http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000075725050

Europe
http://www5.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000075725050

With the vgchid you can change "cpu id"

Regards,
Robert-Jan

Re: Moving Data between servers

MTSU_SAN — Wed, 14 Dec 2005 14:49:01 GMT

Thanks for the document, and the vgchid idea. I'll try my old method and see if the data is on those disks after I move it. But, I'm moving a copy of the disks, not the disks themselves, so it is a little more involved than in this document.

Re: Moving Data between servers

Howard Marshall — Tue, 20 Dec 2005 15:14:12 GMT

Sense you have a disk array that is attached to both servers I recommend the following.

Using the shared disk array, create equivalent volume groups. For example if you have a vg01 then create a vg01a if you have oraclevg create oraclevga or something like that.

Then create equivalent logical volumes and file systems then mount them to relative mount points.

Then you can use cpio on a per file system basis to copy the data from one to the other

#>cd /opt/whateverdir
#>find . -xdev -print | cpio -pdxamv /opt2/whateverdir

you can have more than one instance of this running without overwriting anything sense the find -xdev won't cross mount point .

when the find and cpio commands have copied the files over unmount the relative file systems, export the vg and import it as the correct vg name on the other system.

Do all the testing you want or need, then when its time to convert for real you can just move the database data across.

Re: Moving Data between servers

Howard Marshall — Tue, 20 Dec 2005 15:23:53 GMT

I just thought of another idea that should be as fast as mirroring for you.

Just create the equivalent volume groups and logical volumes but instead of creating file systems just use dd to transfer everything in each logical volume.

The drawback to that though is that you don't get the defragmentation benefits of doing it at the file system level.

H

Re: Moving Data between servers

Alzhy — Wed, 21 Dec 2005 13:54:41 GMT

Unfortunately.. you CANNOT do this with LVM mirroring specially if you want no to minimal downtime. Remember that split mirrors in LVM VG cannot be split off to a separate completely indpendent LVM Volumegroup that can be imported on the other server.

Yo'll need an in-array solution which is array/vendor restrictive -- like Business Copy. But since you plan on mirroring to a diferent Array -- in-array mirror/snapshot/snapclone solutions are not available.

Your only solution is to do cold dd's, cpios, vxdump/vxretore etc. -- which will be disruptive.

Another is you can convert your LVM VG to VxVM - (if you have the full VxVM License) and use VxVM Mirroring.