[CentOS] LVM

Tue Mar 20 09:25:38 UTC 2012
Markus Falb <markus.falb at fasel.at>

On 19.3.2012 10:14, Peter Kjellström wrote:
> On Sunday 18 March 2012 19.40.21 Ray Van Dolson wrote:
>> On Sun, Mar 18, 2012 at 08:04:14PM +0100, Markus Falb wrote:

>>> What filesystem? Assuming ext3, this cannot shrunk without unmounting.
>>> I believe the following *should* work for ext3
>>> $ umount /home
>>> $ e2fsck -f /dev/vg_web/lv_home
>>> $ resize2fs /dev/vg_web/lv_home 150g
>>> $ lvresize -L 150g /dev/vg_web/lv_home
>>> $ mount /home
>>> I am not sure how safe it is. Take care!

> I'd like to add that it's probably good paranoia not to size the lv down too 
> tightly (should it happen to become smaller than the fs then ooops). That is, 
> I'd size the lv down to a comfortable margin above the fs size (and then size 
> the fs up to the device size).

Hmm. I did that too a couple of times in the past.
But why? What are the reasons for the paranoia?

I did a little experiment

$ lvcreate -L1g -ntest1 vg00
$ mkfs.ext3 /dev/vg00/test1
131072 inodes, 262144 blocks
$ lvcreate -L2g -ntest2 vg00
$ mkfs.ext3 /dev/vg00/test2
$ resize2fs /dev/vg00/test2 1g
resize2fs 1.39 (29-May-2006)
Resizing the filesystem on /dev/vg00/test2 to 262144 (4k) blocks.
The filesystem on /dev/vg00/test2 is now 262144 blocks long.

The sizes (262144) match!

Kind Regards, Markus Falb

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