LVM to VxVM migration on 2 storage arrays

[TK Liu]

Hi all HP-UX expert. My server is running HP-UX 11iV1 and has Oracle running on it. The Oracle is running on LVM (old storage) and I want to migrate the data to another volume on VxVM (new storage). What is the best method to do the migration? should I use dd or cp? or using vxvmconvert? Which method is the fastest one and mininum impact to my system? How about if I use MirrorDisk/UX to create a mirror and break it and use vxvmconvert for migration, do you think it is a good method. Please advise. Thank you very much!

[Anthony Grouzdev]

Hi,
and how do you store your oracle data-files - on the raw-volumes or on the filesystem?

[TK Liu]

Hi Anthony,

the data are on LVM (not raw device). Thanks.

[Mridul Shrivastava]

If you want to migrate with minimum impact on the production server, the best thing to do is take full backup of the FS, application etc and then restore them on the new system.

However you can create LVM mirror, break it and then use vxvmconvert but to be onsafer side you have to take backup in this case as well.

[Robert-Jan Goossens · Accepted solution]

Depending on the size of the databases you could also copy them from LVM volumes to VXVM volumes.

# cd /database_fs
# find . -xdev -depth | cpio -pdmvu /cp_database_fs

Regards,
Robert-Jan

[TK Liu]

Hi Mridul, Thanks for your reply. I do backup all the data before the migration. I want to seek for all the possible methods for migration.

[TK Liu]

Hi Robert-Jan,

If the database is a large (about 5TB), should I use other methods instead? Thanks for your great suggestion using cp.

[Robert-Jan Goossens]

I don't think it will realy matter what kind of copy command you will be using, the speed of the copy will depend on the speed of your disk(s) and the controller(s).

examples.
# vxdump -0 -f - -s 1000000 -b 16 /database_fs | (cd /cp_database_fs ; vxrestore rf -)

[TK Liu]

Hi Robert-Jan, thanks for your answer. For your 2nd reply, it use vxdump to copy data from LVM to VxVM, right? During the dumping, do I have to stop the database? How about using the cp command in your first reply? If I use dd for the data migration, do the speed of copying also depend on the storage array and database size? Do you think which is the best method comparing cp, dd, vxdump or LVM mirroring. Sorry for asking so many questions. Thank you very much!!

[Robert-Jan Goossens]

Before you start the copy, stop the database.

As long as there is no network involved, I don't think it does not matter what kind of copy command you use.

dd, cp , cpio, tar vxdump/vxrestore as long as the tool will copy the data without changing any permissions/dates/times etc. That's why cpio and vxdump/vxrestore commands are great tools.

[chris huys_4]

The fastest method is without a doubt vxvmconvert. As you only change the lvm header on every disk to a vxvmheader.