how to lvreduce so that also mounted filesystem is reduced

[Frank de Vries]

On hpux 11.00
I have lvextend a FS (/opt) but I mistook a digit.
Instead of lvextend -l 125 I did lvextend 1250
and ran fsadm accordingly, without realising
my error. Until I did bdf and saw it was a bit
bigger then expected - oops.

Since it happened only seconds ago I think
I can still do lvreduce.
I ran the command lvreduce -l 200
(A bit more so to have some margin, with hindsight). I received the error:
" The Logical Volume has a mounted filesystem on it.
Logical volume "/dev/vg00/lvol6" is not reduced."

I have two questions:
1) How is it technically possible to reduce it,
knowing that I cannot unmount /opt at the
present time (Yes we have MirrorDisk/UX software)
2) Can it be considered safe given that is
so shortly after the lvextend
(Yes, I have a fs backup from today)

I am curious to the replies.
Cheers

[Senthil Kumar .A_1 · Accepted solution]

Hi,

Since you have Online JFS, The steps to reduce the FS is as follows.

1) You need to reduce the filesystem size first.

fsadm -b 200m /usr

Note: here I have assumed the size to be 200MB, if u do not specify "m" it will default to kb.

2) Now reduce the LV

lvreduce -L 200 /dev/vg00/lvol6


NOTE: Before you do this activity, it is better you defragment the /usr FS.

fsadm -d -e /usr

Regards,
Senthil Kumar .A

[Victor BERRIDGE]

Hi
As already mentionned,
To be safe (well if you can...) pass this command first
fsadm -F vxfs -D -d -E -e -s /opt

It will reorganize the file system leaving the empty blocks at the end...

It is no reason to Not make a safe backup before...

All the best
Victor

[Zeev Schultz]

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=975400

[Frank de Vries]

It worked,
thanks a million