KVM : add a storage to running VMs by “virsh attach-disk” command

# tail -1 /etc/lsb-release DISTRIB_DESCRIPTION="Linux Mint 12 Lisa" # uname -ri 3.0.0-16-generic x86_64 # libvirtd --version libvirtd (libvirt) 0.9.2 # virt-manager --version 0.9.0 # kvm --version QEMU emulator version 0.14.1 (qemu-kvm-0.14.1), Copyright (c) 2003-2008 Fabrice Bellard

start a VM ( this VM is openfiler 2.99 )

virsh # start filer01

The VM , fieler01 , has three storage devices , sda , sdb and sdc.

[root@filer01 ~]# dmesg | grep sd[a-z] | grep -i attach sd 0:0:0:0: [sda] Attached SCSI disk sd 0:0:1:0: [sdb] Attached SCSI disk sd 1:0:1:0: [sdc] Attached SCSI disk

add one more storage via virsh

on the KVM host , create a storage file for that VM

# qemu-img create -f raw filer01-data1.img 1G

on the KVM host , add that storage as “/dev/sdd” to that running VM

virsh # attach-disk --driver file filer01 /var/disk1/libvirt/images/filer01-data1.img sdd error: Failed to attach disk error: internal error unsupported driver name 'file' for disk '/var/disk1/libvirt/images/filer01-data1.img'

nnn , error ,,

Let’s check libvirt.log.

/var/log/libvirt/libvirtd.log

error : qemuDomainAttachDeviceDiskLive:3994 : internal error unsupported driver name 'file' for disk '/var/disk1/libvirt/images/filer01-data1.img'

nnnn , I’m not familiar with virsh command…

How about this ?

virsh # attach-disk filer01 /var/disk1/libvirt/images/filer01-data1.img sdd --type disk Disk attached successfully

I could add the storage ( /dev/sdd )

[root@filer01 ~]# dmesg | grep sd[a-z] | grep -i attach sd 0:0:0:0: [sda] Attached SCSI disk sd 0:0:1:0: [sdb] Attached SCSI disk sd 1:0:1:0: [sdc] Attached SCSI disk sd 2:0:3:0: [sdd] Attached SCSI disk

The following is an excerpt of xml file of the VM to which I added a storage via virsh attach-disk

<disk type='block' device='disk'>      <driver name='qemu' type='raw'/>      <source dev='/var/disk1/libvirt/images/filer01-data1.img'/>      <target dev='sdd' bus='scsi'/>      <alias name='scsi0-0-3'/>      <address type='drive' controller='0' bus='0' unit='3'/>    </disk>

The following is via virt-manager

<disk type='file' device='disk'>      <driver name='qemu' type='raw'/>      <source file='/var/disk1/libvirt/images/filer01-data.img'/>      <target dev='hdd' bus='ide'/>      <alias name='ide0-1-1'/>      <address type='drive' controller='0' bus='1' unit='1'/>    </disk>

let’s create a partition on /dev/sdd

warning … partition table is GPT …

[root@filer01 ~]# fdisk /dev/sdd WARNING: GPT (GUID Partition Table) detected on '/dev/sdd'! The util fdisk doesn't support GPT. Use GNU Parted.

change the partition table to msdos from gpt

[root@filer01 ~]# parted /dev/sdd GNU Parted 1.8.8 Using /dev/sdd Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) mklabel Warning: The existing disk label on /dev/sdd will be destroyed and all data on this disk will be lost. Do you want to continue? Yes/No? Yes New disk label type?  [gpt]? msdos (parted) quit Information: You may need to update /etc/fstab.

Ok , no warning message

[root@filer01 ~]# fdisk /dev/sdd Command (m for help): q [root@filer01 ~]#