System Administration

Re: LVM steps to mount a SAN based snapshot back to same host without upsetting original LUN

 
SOLVED
Go to solution
Adam Garsha
Valued Contributor

LVM steps to mount a SAN based snapshot back to same host without upsetting original LUN

Can you confirm or add details to these steps? I seek to present a SAN based LUN copy back to the original HP-UX 11.11 host without upsetting the live/original filesystem. I am working with volume groups that only contain one physical volume and one logical volume.

1. quiesce the app that is accessing the source vxfs filesystem
2. SAN-based snapshot/snapclone of the lone LUN that lives in the volume group that holds the logical volume which contains my filesystem
3. release app back into normal function
4. present new snap LUN back to original host
5. ioscan -f; insf -e
6. since I know LUN # of new LUN, I can figure out the device name(s) <8 paths, so there will be 8 device files; no securepath or other multipathing software is in play; EVA>
7. vgchgid /dev/rdsk/MYNEWLUN
8. mkdir /dev/NEWVG
9. mknod /dev/NEWVG/group c 64 0xNEWNUMBER
10. vgimport /dev/NEWVG /dev/dsk/MYNEWLUN
11. vgchange -a y /dev/NEWVG
12. mkdir /mnt/NEWLV
13. fsck -F vxfs -y /dev/NEWVG/lvol1
14. mount -F vxfs /dev/NEWVG/lvol1 /mnt/NEWLV
3 REPLIES 3
john123
Trusted Contributor
Solution

Re: LVM steps to mount a SAN based snapshot back to same host without upsetting original LUN

plan looks good..
skt_skt
Honored Contributor

Re: LVM steps to mount a SAN based snapshot back to same host without upsetting original LUN

plan looks ok. But I would recommend activating the BCV copy on a different server.
Armin Kunaschik
Esteemed Contributor

Re: LVM steps to mount a SAN based snapshot back to same host without upsetting original LUN

The steps should work.
Make sure you vgchgid all disks at the same time (if more than 1 disk).

Regarding point 6: You should get the tool evainfo (or any other id tool from your storage vendor if it's no EVA) to be able to identify the lun without crude assumptions.

Check http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareDescription.jsp?lang=en&cc=US&swItem=co-52747-1&prodTypeId=12169&prodSeriesId=471497 !

This is very handy especially if you have more than 1 lun.
Depending on your availability/performance constraints you should consider using a multipath software or upgrade to 11.31.

My 2 cents,
Armin
And now for something completely different...