lvextend pain

[Kevin Epstein]

Hi All,

I very absent-mindedly did an lvextend on a logical volume that was still mounted! The lv was not extended, but if I do a vgdisplay I see that the extents have been used up! how can I reverse what I've done?

I've thought of lvreducing the logical volume and then re-extending it. I realise I'll probably end up having to go to backup tapes to restore the data.

Before I try this I was hoping that someone could confirm that this is the way to go, of if someone can suggest a better way.

Thanks.

[James R. Ferguson]

Hi Kevin:

I think you mean that you *did* the 'lvextend' on the logical volume, but did *not* exten the file system.

If that is the case, you should be able to 'lvreduce' the logical volume back to its original size without harm.

As insurance, of course, be sure to backup the filesystem that lives in the logical volume beforehand!

Regards!

...JRF...

[Kevin Epstein]

Hi,

I think you're right. I did lvextend -L 20000 /dev/vg02/lvol1

Can I not just do the extendfs command now?
Do I have to first reduce?

Kevin

[Pete Randall]

You should be able to unmount the file system and run extendfs. No need to lvreduce.


Pete

[James R. Ferguson]

Hi (again):

Again, if I understood you, and you mean that you 'lvextend'ed the wrong logical volume, and thus you want to reclaim the phyical extents it took, then read my first post.

If you mis-sized the logical volume too large, you can also 'lvreduce' it to a smaller size, AS LONG AS you do not reduce it smaller than the size of the fileystem it contains. Then extend the filesystem.

Regards!

...JRF...

[SGUX]

The LV still being mounted is no problem.
The extends have not been used since you did not extend the filesystem yet, so lvreducing should be OK if you need these extends for another LV. If you would like to extend this FS then this could be done on-line when you have onlineJFS installed using "fsadm -F vxfs -b ........" (see man fsadm_vxfs) [if this is a vxfs-FS) If no onlineJFS is available then the only option is unmounting the filesystem and use "extendfs ....."

[Kevin Epstein]

Hey All - it's been a long week. After the first response about not actually extending the FS I realized no mistake had been made - rather I'd only done half the job!
After unmounting and doing the extendfs all was well in the world once again.

Thanks again for all the replies
Kevin

[Kevin Epstein]

Thanks all