On Thu, Jun 07, 2012 at 02:49:14PM +0200, Sebastien Douche wrote:
On Ubuntu 12.04, I'm trying to create a second disk for a VM. The
disk
seems work well (and mounted) but I don't like the cfdisk / fdisk
message.
# virt-make-fs --partition --size=+300M --type=ext3 --format=qcow2
srv-2912.tar.gz datadisk-test.qcow2
Formatting 'datadisk-test.qcow2', fmt=qcow2 size=393837568
encryption=off cluster_size=65536
# virt-filesystems -a datadisk-test.qcow2
/dev/sda1
I add the disk on the VM:
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2' cache='none'/>
<source file='/srv/kvm/lib/datadisk-test.qcow2'/>
<target dev='hdb' bus='ide'/>
<address type='drive' controller='0' bus='1'
unit='0'/>
</disk>
The dmesg seems good :
[ 1.404447] scsi 1:0:0:0: Direct-Access ATA QEMU HARDDISK
1.0 PQ: 0 ANSI: 5
[ 1.545945] sd 0:0:0:0: [sda] 8388608 512-byte logical blocks:
(4.29 GB/4.00 GiB)
[ 1.554467] sd 1:0:0:0: [sdb] 769214 512-byte logical blocks: (393
MB/375 MiB)
[ 1.555975] sd 1:0:0:0: [sdb] Write Protect is off
[ 1.556943] sd 1:0:0:0: [sdb] Mode Sense: 00 3a 00 00
[ 1.556969] sd 1:0:0:0: [sdb] Write cache: enabled, read cache:
enabled, doesn't support DPO or FUA
[ 1.559923] sdb:
[ 1.560603] sd 0:0:0:0: [sda] Write Protect is off
[ 1.561837] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[ 1.561864] sd 0:0:0:0: [sda] Write cache: enabled, read cache:
enabled, doesn't support DPO or FUA
[ 1.563637] sda: sdb1
But fdisk said :
Command (m for help): p
Disk /dev/sdb: 393 MB, 393837568 bytes
223 heads, 46 sectors/track, 74 cylinders
Units = cylinders of 10258 * 512 = 5252096 bytes
Disk identifier: 0x0002345e
Device Boot Start End Blocks Id System
/dev/sdb1 1 75 384479+ 83 Linux
Partition 1 has different physical/logical beginnings (non-Linux?):
phys=(0, 2, 3) logical=(0, 2, 37)
Partition 1 has different physical/logical endings:
phys=(47, 222, 46) logical=(74, 217, 13)
And cfdisk:
FATAL ERROR: Bad primary partition 0: Partition ends in the final
partial cylinder
Have I missed something? Any ideas?
This is caused because virtio (used by libguestfs) and the IDE
emulation (used by your VM) guess different CHS values for this disk.
To be honest I would simply ignore this warning, since CHS values
don't matter for virtual machine disks. If you really want to fix it,
you could modify your guest to use virtio-blk, which will also make
the guest run much faster.
Rich.
--
Richard Jones, Virtualization Group, Red Hat
http://people.redhat.com/~rjones
libguestfs lets you edit virtual machines. Supports shell scripting,
bindings from many languages.
http://libguestfs.org