[linux-lvm] How to increase/decrease space

Klaus Strebel klaus.strebel at gmx.net
Thu Dec 16 16:22:02 UTC 2004

AdabalaP at schneider.com wrote:
Hi Abdala,

seem's that you mix disks, partions, and filesystems. Here a little 
PC-primer that you get an idea what all the other people are talking about.

1. You have a disk - obviously an IDE-drive 'caue the Linux device name 
is hda.

2. On the disk, you have 2 Partitions, named hda1 and hda2.

3. On the first partition, you have an ext3 filesystem (?) probably for 
/boot ??, the second partition is the only phisical volume of your 
volume group VolGrp00 managed by LVM2, countaining several logical volumes.

4. The logical volumes in your volume group VolGrp00 containing are 
formatted with a ext3 filesystem.

> Austine,
> I have a hard disk of 4.8GB which i partitioned it into 2 parts (hda1 = 100
> meg, hda2 = 4.7gb). The whole disk is of ext3 file system type.
This means, that /dev/hda is an ext3 filesystem ... if that's the case, 
then the filesystem spans all partiotions and all the logical volumes 
and if you were able to mount it, you will surely damage all the other 
stuff on you drive ... well, you can't : i think Linux doesn't allow 
mounting of overlapping devices/partitions, and if it does, the 
filesystem is surely already damaged ...

> The hda2 is managed by using lvm2.
But you said, all drive is ext3 - well, seems you mixed something up ;-)

> Following is the partition sizes of the hda2 disk;
> hda2        VolGrp00          4.6 gb
> /           VolGrp00/LogVol00 450 meg     35% used
> /usr        VolGrp00/LogVol04 1.9 gb      92% used
> /usr/local  VolGrp00/LogVol05 128 meg     25% used
> /home       VolGrp00/LogVol03 128 meg     60% used
> /opt        VolGrp00/LogVol02 128 meg     35% used
> /var        VolGrp00/LogVol07 450 meg     30 % used
> swap        VolGrp00/LogVol01 342 meg
> Here is sequence of steps that i have performed to inc/dec the partition
> sizes;
> tried to increase /usr size by 400 meg.
>       #lvresize -L +450 VolGrp00/LogVol04
>       when i display using the "lvdisplay VolGrp00/LogVOl04" i see 2.4 gig
> allocated to this partition, but when i   see it through "df -m /usr" it
> hasn't changed.
>       So, As per Jason's email i have done the below;
>       #lvextend -L2.4G VolGrp00/LogVol04
So you resized the logical volumes, which is a kind of 'virtual 
partition', but the filesystem is still of the same size, it doesn't 
recognize the the 'device' or 'partition' it lives on has grown, so you 
have to tell him to (Jason Martin told you earlier, and pointed you to 
the LVM-HOWTO <http://tldp.org/HOWTO/LVM-HOWTO/extendlv.html>).

Instead of complainig you should have better read that doc, and you'd 
know what to do.

>       But again this hasn't changed my "df -m /usr" output.
> I thought using LVM commands one should be able to take care of the inc/dec
> of partitions sizes under a given VG. Why should i be using "fdisk" and
> "e2fsadm" ?
Well, if you'd read the e2fsadm man page before growing your lvol, you'd 
  have known what to do. For an offline ext3 (don't know Fedora, 
propably they aleady use the online resize patches for ext3 ?), you can 
use resize2fs to grow your filesystem.

> If i have missed or done any thing wrong while resizing the partitions can
> please provide me an example so that i could try it.
Jason pointed you there in the first reply to your request, so Read That 
Fucking Manual ;-).


Mit freundlichen Grüssen / best regards

Klaus Strebel, Dipl.-Inform. (FH), mailto:klaus.strebel at gmx.net

/ \

More information about the linux-lvm mailing list