[CentOS] Resizing est4 filesystem while mounted

Tue Jun 19 17:24:07 UTC 2012
Jeff Boyce <jboyce at meridianenv.com>

Replying to the daily digest, with my response at the bottom.

> Message: 18
> Date: Mon, 18 Jun 2012 22:28:31 +0200
> From: Dennis Jacobfeuerborn <dennisml at conversis.de>
> Subject: Re: [CentOS] Resizing est4 filesystem while mounted
> To: centos at centos.org
> Message-ID: <4FDF8F6F.8030300 at conversis.de>
> Content-Type: text/plain; charset=ISO-8859-1
> On 06/18/2012 10:09 PM, Jeff Boyce wrote:
>> Replying to the daily digest, with my response at the bottom.
>>> Message: 13
>>> Date: Fri, 15 Jun 2012 12:22:08 -0700
>>> From: Ray Van Dolson <rayvd at bludgeon.org>
>>> Subject: Re: [CentOS] Resizing est4 filesystem while mounted
>>> To: centos at centos.org
>>> Message-ID: <20120615192207.GA23689 at bludgeon.org>
>>> Content-Type: text/plain; charset=us-ascii
>>> On Fri, Jun 15, 2012 at 12:10:09PM -0700, Jeff Boyce wrote:
>>>> Greetings -
>>>> I had a logical volume that was running out of space on a virtual
>>>> machine.
>>>> I successfully expanded the LV using lvextend, and lvdisplay shows that
>>>> it
>>>> has been expanded. Then I went to expand the filesystem to fill the new
>>>> space (# resize2fs -p /dev/vde1) and I get the results that the
>>>> filesystem
>>>> is already xx blocks long, nothing to do. If I do a # df -h, I can see
>>>> that
>>>> the filesystem has not been extended. I could kick the users off the 
>>>> VM,
>>>> reboot the VM using a GParted live CD and extend the filesystem that 
>>>> way,
>>>> but I thought that it was possible to do this live and mounted? The RH
>>>> docs
>>>> say this is possible; the man page for resize2fs also says it is 
>>>> possible
>>>> with ext4. What am I missing here? This is a Centos 6.2 VM with an ext4
>>>> filesystem. The logical volumes are setup on the host system which is
>>>> also
>>>> a Centos 6.2 system.
>>> Try resize4fs (assuming your FS is ext4).
>>> Ray
>> Well, I have never seen a reference to resize4fs before (and yes my FS is
>> ext4).  It is not on my Centos 6.2 system, and doing a little searching
>> through repositories for that specifically, or e4fsprogs, and I can't 
>> find
>> it anywhere to even try it.  Any google reference seems to point back to
>> resize2fs.  I ended up booting a live SystemRescueCD and using GParted 
>> via
>> the GUI.  My notes indicate that is what I had done previously also.  I 
>> am
>> still stumped, everything that I have read indicates that resize2fs can 
>> do a
>> live resizing on ext4 file systems.  Can anybody confirm or deny this? 
>> Is
>> the reason I can't do this because it is on an LVM logical volume? 
>> Thanks.
> Please post some details about your storage topology. Without this
> information its not really possible to be sure what is going on.
> resizefs cannot work as long as the underlying layers don't see any change
> in size and you didn't seem to look for that.
> Regards,
>   Dennis

I provided some of that information in my original post, but if you can help 
explain why I couldn't seem to resize the file system while mounted here is 
more information.

Host system is Centos 6.2 on a Dell PE T610 with hardware raid on a PERC 
H700.  Raid 5 is setup across three disks with a fourth hot spare.  I have 
created a volume group within the raid 5 encompassing most of my drive 
space.  Within the VG I have created numerous logical volumes that are 
assigned to specific systems.

Volume Group:  vg_mei
Logical Volumes:

Earth is my host system and Sequoia is one of the guest systems. 
lv_sequoiaecosystem is the space dedicated to our Samba server and is the LV 
that I was expanding to make more space available to the rest of the staff. 
I had successfully extended lv_sequoiaecosystem using the following command 
from root on earth (lvextend -L+50G /dev/vg_mei/lv_sequoiaecosystem). 
Issuing the command  (lvdisplay /dev/vg_mei/lv_sequoiaecosystem) following 
this showed that the LV was successfully extended from 100 to 150 GB.

I then logged onto sequoia as root and issued a df -h to determine which 
device needed the file system to be resized (/dev/vde1).  The output below 
is current, after I resized the filesystem using GParted.

[root at sequoia ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/vda2             4.5G  2.5G  1.8G  59% /
tmpfs                1004M  112K 1004M   1% /dev/shm
/dev/vda1             485M   55M  406M  12% /boot
/dev/vde1             148G   85G   56G  61% /ecosystem
/dev/vdd1              20G  1.3G   18G   7% /home
/dev/vdc1             2.0G  266M  1.7G  14% /var

Then from root on sequoia I issued the command (resize2fs -p /dev/vde1) and 
got back the result that the filesystem is already 26214144 blocks long, 
nothing to do.  That is when I posted my first question about not being able 
to resize a live mounted filesystem.  Is that enough information for your 
question, or is there something that I am not providing?  Thanks.