use xvda instead of sda on xen 4.0

Cloudmin
1

New XEN 4.0 xen-tools recommends to use xvda instead sda for block devices like disks.

How about implementation configure parameter in “Xen Host Settings”?

Thanks for good software. :slight_smile:

2

Do they recommend using xvda in the Xen .cfg file, or in the /etc/fstab file on the VM?

Cloudmin currently uses xvda in /etc/fstab if the kernel supports it.

3

Here block of /etc/xen-tools/xen-tools.conf

If you’re using the lenny or later version of the Xen guest kernel you will

need to make sure that you use ‘hvc0’ for the guest serial device,

and ‘xvdX’ instead of ‘sdX’ for serial devices.

You may specify the things to use here:

serial_device = hvc0 #default

serial_device = tty1

disk_device = xvda #default

disk_device = sda

I use Debian 6 as host system and try to create debian 5 and 6 based VMs by using PyGrub. all VMs creates with /dev/sda partitions.

4

Cloudmin 5.8 and later should solve this issue, as VM images that support xvda devices use /dev/xvda1 in their /etc/fstab file. This will be preserved when the VM is created…

5

Sounds good but in practice i always have sda based partitions by default even if VM configured use xvda in fstab.
May be this inconvience present only in GPL version that i have in use? I use latest version of cloudmin.

It’s not very big problem for me. I can always rename partitions for VM’s. But this is not right way. :o)

6

So do you mean your xen config file uses sda device names, or do they appear somewhere else in your vm?

7

I can confirm the issue: the xen config file always creates “sda” entries, even if the fstab shows xvda.
More, it would be nice to have the possibility to set options like “extra=‘elevator=noop’” on specific images’ configs.

8

Does the user of sda instead of xvda in the Xen config cause problems though?

9

It does, actually, as the machine doesn’t boot: the xen config file sets also the “root=/dev/sdaX” option so the machine boots up, searches for sdaX, doesn’t find it and panics. If I change manually to “xvdaX”, it is able to boot perfectly.

10

Thanks - I forgot about that case, as most users boot their VMs using pygrub, in which case the root line isn’t needed. I will fix this in the next Cloudmin release.

11

Thank you very much.
I would love to deploy a Cloudmin install on a Debian Squeeze dom0, and I’m trying to find out all the possible problems.
Cloudmin (as all the *min projects) is a great piece of software. Thank you for that.

12

Sounds good. Thanks for great software.