/tmp = EXT3, the VM images gives EXT4-fs error

[Edgar]

((Ok, this is the first time every I file a bug, so give me also feedback when I report wrong..))

First of all, I want to build a system for production in wich I can build (very) fast new VM's.
I installed Ubuntu Server 10.04.2 64Bit as host OS with the following partitions:

/Boot [Prim] 1GB (EXT4)
/ [Prim] 25GB (EXT4)
swap [Prim] 25GB (swap)
---extended---
/tmp [Logical] 25GB (EXT4)
/var/log [Logical] 10GB (EXT4)
lvm [Logical] 1,5TB (lvm)

When I use VMBuilder and build to a RAW logica volume (lvm), it takes more than 12 minutes!
Then I tried to change the /tmp partition (of the HOST) to EXT3 and it did take less than 4 minutes!!!!

The only problem now is that the VM gives the following error on startup:
EXT4-fs error (device sda1): ext4_mb_generate_buddy:
EXT4-fs group 2: 3431 blocks in bitmap, 3597 in gd

Any ideas?
Maybe first any ideas for a workaround?

[Serge Hallyn (serge-hallyn)]

> ((Ok, this is the first time every I file a bug, so give me also
> feedback when I report wrong..))

Thanks for taking the time to report this bug.

> First of all, I want to build a system for production in wich I can build (very) fast new VM's.
> I installed Ubuntu Server 10.04.2 64Bit as host OS with the following partitions:
>
> /Boot [Prim] 1GB (EXT4)
> / [Prim] 25GB (EXT4)
> swap [Prim] 25GB (swap)
> ---extended---
> /tmp [Logical] 25GB (EXT4)
> /var/log [Logical] 10GB (EXT4)
> lvm [Logical] 1,5TB (lvm)
>
> When I use VMBuilder and build to a RAW logica volume (lvm), it takes more than 12 minutes!

I'd recommend building a single pristine image (where time to build doesn't matter), and
snapshot or copy that when you need a new image and make the few changes you need to.

Maybe that was your plan all along, but since you mention the time it took to make the
first image, I wasn't sure.

> Then I tried to change the /tmp partition (of the HOST) to EXT3 and it did take less than 4 minutes!!!!

Interesting.

Are you using a local archive mirror? It's possible that if you switch back
to ext4 now it'll go much faster.

> The only problem now is that the VM gives the following error on startup:
> EXT4-fs error (device sda1): ext4_mb_generate_buddy:
> EXT4-fs group 2: 3431 blocks in bitmap, 3597 in gd
>
> Any ideas?

Is sda1 your tmpfs? If so, edit your fstab to mark it as ext3.

> Maybe first any ideas for a workaround?

Actually long-term for most image building we recommend switching to live-build. If you try that, and your host has enough memory (more than 4G), then building out of a tmpfs can make for very fast, 2-4 minute, image builds. Please feel free to ask for help on irc on freenode#ubuntu-server or on the ubuntu-server mailing list.

[Serge Hallyn (serge-hallyn)]

Please give us the full command line and any configuration files which you used to run vmbuilder, so I can try to reproduce the ext4 booting error.

Actually I'm wondering whether this is a duplicate of bug 578199. Would you mind testing by doing:

   cd /tmp
   wget https://code.launchpad.net/~brightbox/vmbuilder/exclude-first-cylinder/+merge/42530/+preview-diff/+files/preview.diff
   cd /usr/lib/python2.6/dist-packages
   patch -p0 < /tmp/preview.diff

then re-building your VM?

[Edgar (edgar-nl)]

> Actually I'm wondering whether this is a duplicate of bug 578199.

I did the patch, but same result... :-(

> I'd recommend building a single pristine image (where time to build doesn't matter), and snapshot or copy that when you need a new image and make the few changes you need to.

It's an idea for some VMs, but we also want to build a lot of 'disposable' VMs completly 'new' with complete diffrent build scripts and parameters...

> Interesting... ( /tmp [EXT4] -> [EXT3] )

See also: https://wiki.ubuntu.com/LucidLynx/ReleaseNotes#Performance regressions with ext4 under certain workloads

> Are you using a local archive mirror?
> It's possible that if you switch back to ext4 now it'll go much faster.

I have in our network an "apt-mirror" server.
Another machine, but is own Gigabit connection...

> Is sda1 your tmpfs?
> If so, edit your fstab to mark it as ext3.

I have my tmpfs on default. (not filled in)

> Please give us the full command line and any configuration files which you used to run vmbuilder, so I can try to reproduce the ext4 booting error.

## BuidVmRaw.sh ##

lvcreate -L 10G -n "$VAR_HostName" vg-1;
vmbuilder kvm ubuntu \
        --config="defaultVM.cfg" \
        -o \
        --hostname="$VAR_HostName" \
        --raw="/dev/vg-1/$VAR_HostName"
        --firstboot="$VAR_firstBoot" \
        --firstlogin="$VAR_firstLogin" \
        --ssh-user-key="/home/locadm/.ssh/authorized_keys" \
        --verbose;

## defaultVM.cfg ##

[DEFAULT]
arch = amd64
cpus = 1
mem = 512
name = 'Local Administrator'
user = locadm
pass = default
timezone = Europe/Amsterdam
domain = company.lan

[ubuntu]
mirror = http://archive.ubuntu.company.lan/ubuntu
security-mirror = http://security.ubuntu.company.lan/ubuntu
suite = lucid
flavour = virtual
addpkg = acpid, cron, htop, nano, pciutils, wget

[kvm]
libvirt = qemu:///system
bridge = br0
virtio_net = true

## ##

I also noticed that the "--firstboot" and the "--firstlogin" don't work,
but first the big EXT4-fs error...

[Launchpad Janitor (janitor)]

[Expired for vm-builder (Ubuntu) because there has been no activity for 60 days.]