topic Re: LVM in Operating System - HP-UX

LVM

Amitav — Thu, 06 Sep 2007 00:17:06 GMT

I'm new to HP unix, how can i move data's across VG's. Though i know it can be done thru the cmd's like dd, mv, cp, tar, cpio....but i know have the knowledge how to use them(esp. dd, tar & cpio)...?? Can somebody help me out.....

Re: LVM

Amit Parui — Thu, 06 Sep 2007 00:55:11 GMT

Hi Amitav,

Firstly dd can only be used to dump data from one disk to another, mainly used in case of whole disk backups.

#dd if=/dev/rdsk/c?t?d? of=/dev/rdsk/c?t?d? bs=1024 (in multiples of 2)

In,the above command first you've to get two disks from two different vg's, but the only problem would be to find out any paricular filesets in this case. Else you can dump the whole disk to other disk, which should supposedly have enough space, and you are done.

Secondly using tar would be much feasible in case of selected filesets -

#tar -cvf myarchive `cat /tmp/aa`
or
#cat /tmp/aa | xargs tar -cvf aa.tar

Also,if there are many files to be archived, you can use 'pax', which can write tar-format but can read the files to be archived from stdin as well:

#pax -w -f myarchive.tar After this move the tar file to the desired location.

Try this syntax
# find . -print | cpio -pdmuv > /tmp/myarchive.cpio

Test it out, but this syntax should keep the ownerships and permissions intact.

Re: LVM

Steven E. Protter — Thu, 06 Sep 2007 00:56:45 GMT

Shalom,

When you say across volume groups, you mean from one volume group to another?

You actually list many of my preferred choices.

I also for not totally huge moves use scp, to move across a network between machines.

If you want to migrate a whole volume group you can use vgexport followed by vgimport.

SEP

Re: LVM

Prasanth V Aravind — Thu, 06 Sep 2007 06:01:34 GMT

get system administartion tasks.pdf from docs.hp.cpm

Re: LVM

Prasanth V Aravind — Thu, 06 Sep 2007 06:08:24 GMT

sending the link

http://docs.hp.com/en/B2355-90672/B2355-90672.pdf

Re: LVM

Wim Rombauts — Thu, 06 Sep 2007 07:06:21 GMT

What data do you want to move ?
If you want to create a new VG with the same configuration as the old VG, or modify a VG to give it the same configuration as the old VG, vgexport (with -p option !) and vgimport is your way to go.
If you want to copy the contents of a RAW LV to another RAW LV in another VG, then dd is the way to go, but then you are copying LV-contents, not VG's. (VG's in fact only contain configuration information, so that is all you can copy if you talk about VG's)
If you want to copy filesystems between LV's (and it doesn't matter if it is a different VG or not), use filesystem tools like cp -pr (if you can directly access both filesystems), or tar or cpio.

To give more detailed command explanations, a good starting point is to look at the man pages, or to specify here what type of data you want to copy.