new LVM user - question about extending the root filesystem

[James Haltom]

Hi. I curently have 5 gigs available in vg00.
I'd like to use 1gb to extend the root filesystem. My system has online JFS. I was wondering if there are any issues with just running the lvextend and fsadm commands like i would w/ any other filesystem. thanks,

jim

[Con O'Kelly · Accepted solution]

Hi Jim

Unfortunately thats not possible as the root filesystem needs to be contiguous.
The normal way to extend root is to make an Ignite-UX backup and then extend the root FS using Ignite-UX.

However its normally not necessary to increase root. A cleanup should usually clear some space. What is the current size of root filesystem??

Cheers
Con

[James Haltom]

Thanks for the answer con. The root filesystem is only 68%. I will perform a check of the filesystem for files to delete. The main reason i asked is that we have so much space available on vg00 and would have liked to simply extend it a bit.

-jim

[Con O'Kelly]

Hi Jim

Generally a root filesystem should not grow much. I'd generally size it at between 128MB - 256MB. If you have space issues, its generally because a file has been placed there that shouldn't be there or an application has dumped a core file.

A much more suitable FS for extending is /var.
My advice is keep the space available in the Vol Group until its needed.

Cheers
Con

[James Murtagh]

Hi James,

You can do this with a bit of tinkering. As mentioned, the logical volume that root resides in must be contiguous. If you have a seperate lvol for /stand and the root lvol is after the primary swap (i.e. it is lvol3) then you can move lvol4 (or whatever follows roots extents - see pvdisplay) to another part of the disk(s) and then lvextend lvol3 where it used to be. If part of this free space in vg00 is on another disk it is easy to move lvol4 - just use pvmove. If it is not (and it is a filesystem) then you may have to bring the system down to single user mode and do the copy there.

cheers,

James.

[James Haltom]

Thanks for the advice gentleman. I will use some of the space for /var which is actually using 78% capacity. The rest will be saved for a rainy day. Cheers,

jim

[T G Manikandan]

The best way would be to use Ignite for that.

Build up ignite tapes using make_tape_recovery.

From the tape you can re-build the system with allocating more space for the file systems.


There is a doc in the techbase

http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000062908171


Anyhow make sure you have your system images before proceeding further.