Activating and deactivating a volume group

[Sanjay Yugal Kishore Ha]

Hi all,

I'm trying to understand the activation/deactivation of volume groups under LVM.

1. What does deactivating of a VG actually mean?
2. Is it necessary to unmount the filesystems and remove the LVs that were part of the VG? Why?
3. After a VG has been deactivated, can the disk(s) using which the VG was created, be reused for creating a new VG?

Any suitable documentation on the Sys Admin tasks related to VG administration would be appreciated. (Of course, I'm going through the vgchange and vgcreate man pages at the moment.)

Thanks in advance,
Sanjay

[Pete Randall]

Sanjay,

1. Activating/deactivating is simply the process of making the VG available to the system (you could think of it as "mounting" the VG, I guess).

2. Yes, you would want to umount the filesystems but no, you don't need to remove the lvols to deactivate.

3. In order to reuse the disk, you would first need to destroy the LVM information on them via lvremove/vgremove.


Pete

[Thierry Poels_1]

Hi,

1. deactivating (vgchange -a n) is used for disk which are share between several servers, especially in MC/ServiceGuard clusters.

2. all filesystems of the relevant VG have to be unmounted first, but they don't have to be deleted.

3. after a VG has been deactivated, you can activate it again on the same server, or another server. The disks can be reused to create a new VG, but this is not really the purpose of deactivating the VG.

regards,
Thierry.

[Steven E. Protter]

1. Its like taking the volume group offline.
This allows you to export/import it into another machine if the disk is shared.

2. Depends on what you plan to do. If you are merely working on the volume group no. If you want to export the disk to another machine, yes, you should umount the filesystems.

3. The command vgreduce lets you takes disks out of a volume group. You'll need to lvremove the logical volumes first.

docs:
http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/5187-0701/5187-0701_top.html&con=/hpux/onlinedocs/5187-0701/00/00/38-con.html&toc=/hpux/onlinedocs/5187-0701/00/00/38-toc.html&searchterms=LVM&queryid=20031110-094655




SEP

[Michael Steele_2]

There use to be very good courses but I see only this online LVM course now:

http://education.itresourcecenter.hp.com/TrainerII/en_US/catalog/catalogDetail.jsp?id=tprodid002681

Here's the list of courses:

http://www.hp.com/education/sections/hpux.html

[Hemanth Gurunath Basrur]

Hello Sanjay,

Refer to the foll. links for info.

http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B5158-90018/B5158-90018_top.html&con=/hpux/onlinedocs/B5158-90018/00/00/56-con.html&toc=/hpux/onlinedocs/B5158-90018/00/00/56-toc.html&searchterms=a%7cvolume%7cgroup%7cdeactivating&queryid=20031110-202215

http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B3936-90024/B3936-90024_top.html&con=/hpux/onlinedocs/B3936-90024/00/00/23-con.html&toc=/hpux/onlinedocs/B3936-90024/00/00/23-toc.html&searchterms=group%7cvolume&queryid=20031110-201747

http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B2355-90664/B2355-90664_top.html&con=/hpux/onlinedocs/B2355-90664/00/00/43-con.html&toc=/hpux/onlinedocs/B2355-90664/00/00/43-toc.html&searchterms=the%7cfilesystems%7cremove%7clogical%7cvolumes%7cthat%7cwere%7cpart%7cof%7cthe%7cvolume%7cgroup%7cunmount&queryid=20031110-203011

http://us-support.external.hp.com/emse/bin/doc.pl/emse/bin/doc.pl/distrib_redir=0+1068521769|*?rn=25&source=7000&hpl=1&from=forums&searchcategory=ALL&todo=search&origin=0&wpa=forums1.itrc.hp.com%3A80&searchcriteria=allwords&submit.x=0&searchtext=volume+group&esc=us-support2.external.hp.com&submit.y=0&chkServStor=on&presort=rank

HTH.

Regards,
Hemanth

[aparna challagulla]

hi Sanjay,

Pl go through these docs.

http://www1.itrc.hp.com/service/iv/docDisplay.do?docId=/DE_SW_UX_swrec_EN_01_E/LVM.pdf

http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B2355-90672/B2355-90672_top.html&con=/hpux/onlinedocs/B2355-90672/00/00/1-con.html&toc=/hpux/onlinedocs/B2355-90672/00/00/1-toc.html&searchterms=system%7cadministration%7ctasks%7chp-ux&queryid=20031110-231111

HTH
aparna