Reducing the size of vg00

[Donald Lalonde]

OK, now that I have my backup disk working, I need to make some changes to the master disk.

I need to create space for my oracle database.
But, I vg00 is taking up most of the space.

There is a lot of free space on vg00 and I was hoping to use it for my new group vg01.
How can I reduce the size of vg01?

Thanks
Don

[IT_2007 · Accepted solution]

Do you mean you want to wipe out master disk and recreate as vg01? Please clarify.

Better not to create any database logical volumes on vg00 eventhough you have free space.

Look into vg01 logical volumes which ones have old log files, tar and gz files which you may delete and free up some space.

[Donald Lalonde]

OK, I only have 1 disk and vg00 is taking up most of the space.

I want to keep the OS and all of it's files on vg00. But, I want to reduce it's size so that I can create a vg01.

Both vg00 and vg01 will be on the same disk c0t0d0

Thanks

[IT_2007]

You misunderstood concept of LVM. Per Volume group you need to dedicate one physical volume and you can't do assign same physical disk to two volume groups. You need to get another free physical disk to create vg01.

[James R. Ferguson]

Hi DOn:

> There is a lot of free space on vg00 and I was hoping to use it for my new group vg01.

If the vg00 volume group actually contains multiple physical volumes, *and* there are enough free physical extents on one or more physical volumes to be able to 'vgreduce' a physical volume from the volume group, *then* and only then could you create a new volume group (e.g. "vg01").

I strongly urge you *not* to add non-standard logical volume and filesystems to vg00. If you retain vg00 only for the operating system, you will greatly simplify upgrades and cold-installs. WIth today's large physical disk this often means that the major fraction of the usuable physical disk space in vg00 is unused.

Different LVM volume groups cannot span the same physical disk volumes. For a quick overview, see the manpages for 'lvm(7)'.

A 'vgdisplay -v' will show you every active volume group on your server, along with the physical volumes it contains and the logical volumes defined on each volume group.

Regards!

...JRF...

[Donald Lalonde]

Ooops, so I can't have a vg00 and a vg01 on the same disk.

OK, now what...

What would happen if I created my Oracle directories in separate logical volumes on vg00

/var/oracle1 would be vg00/lvol10
/var/oracle2 would be vg00/lvol11

etc...

Would this cause any problems with patches or upgrades to HPUX?

[James R. Ferguson]

Hi (again) Don:

> What would happen if I created my Oracle directories in separate logical volumes on vg00?

Again, I urge you not to create non-standard logical volumes for non-operating system filesystems on vg00.

Not doing this, makes cold-installations, upgrades of the operating system, and Ignite recovery and cloning much, much cleaner.

I would buy and add more physical disk to your server. *However*, if you "must" create an Oracle filesystem and have no other free disk nor free physical extents in a non-vg00 volume group, then proceed understanding the above caveat.

In addition, when you make an Ignite recovery image of vg00, be sure to use '-x exclude /var/oracle1' and '-x exclude /var/oracle2' etc. in your 'make_tape_recovery' command string. In this way, at least, you will get the equalivent image of a "clean" vg00.

Regards!

...JRF...

[IT_2007]

Ooops, so I can't have a vg00 and a vg01 on the same disk.

OK, now what...

What would happen if I created my Oracle directories in separate logical volumes on vg00

/var/oracle1 would be vg00/lvol10
/var/oracle2 would be vg00/lvol11

etc...

Would this cause any problems with patches or upgrades to HPUX?
=========================================
It is not good practice to put Oracle logical volumes in vg00. But if you don't have other options then proceed further.

As JRF said above exclude those mount points while you take ignite backup so that you can restore OS whenever needed. But make sure that your Oracle mount points get beacked up by your normal backup software like omni or veritas.

[Donald Lalonde]

Thanks for the help guys.

I'll talk it over with my manager and let them make the decisions.

Don