RHEL6 KVM: Add dir based pool volume to guest: CLI HOWTO?

chrism01 · 08-31-2012, 01:04 AM

Hi Guys,

have created a dir based pool eg Section 11.1.3.2 https://access.redhat.com/knowledge/...age_Pools.html and 2 volumes within using 12.1 (vol create) & 12.2 (clone vol) from same docco.

Results

Code:

# virsh pool-list --details
Name             State    Autostart  Persistent   Capacity  Allocation  Available
---------------------------------------------------------------------------------
default          running  yes        yes         834.81 GB    12.56 GB  822.25 GB
dir_pool_images  running  yes        yes         834.81 GB    12.56 GB  822.25 GB

# virsh vol-list --details default
Name     Path                             Type  Capacity  Allocation
--------------------------------------------------------------------
vm1.img  /var/lib/libvirt/images/vm1.img  file  20.00 GB     6.13 GB
vm2.img  /var/lib/libvirt/images/vm2.img  file  20.00 GB     6.13 GB

# virsh vol-list --details dir_pool_images
Name  Path                            Type  Capacity  Allocation
----------------------------------------------------------------
vol1  /var/lib/libvirt/dir_pool/vol1  file   9.31 GB     9.31 GB
vol2  /var/lib/libvirt/dir_pool/vol2  file   9.31 GB     8.00 KB

1st 2 are working vms, 2nd 2 are new storage volumes.

QN: How (cli only) can I assign theses vols to the running vms?

barghota · 09-01-2012, 08:03 PM

From 'man virsh';

Quote:

attach-disk domain-id source target optional --driver driver --subdriver subdriver --type type --mode mode --persistent --sourcetype soucetype
Attach a new disk device to the domain. source and target are paths for the files and devices. driver can be file, tap or phy depending on the kind of access. type can indicate cdrom or floppy as alternative to the disk default, although this use only replaces the media within the existing virtual cdrom or floppy device; consider using update-device for this usage instead. mode can specify the two specific mode readonly or shareable. persistent indicates the changes will affect the next boot of the domain. sourcetype can indicate the type of source (block|file)

So,

# virsh machine01 /var/lib/libvirt/dir_pool/vol2 vde
# virsh machine01 /var/lib/libvirt/images/vm1.img vdf

vd[ef]: where the disk will appear under /dev on the guest

Or however you would like to attach them.

chrism01 · 09-02-2012, 11:02 PM

Tried a few variations; no joy

Code:

 virsh attach-disk vm1 /var/lib/libvirt/dir_pool/vol1 vde
error: Failed to attach disk
error: internal error unable to execute QEMU command '__com.redhat_drive_add': Device 'drive-virtio-disk4' could not be initialized


virsh attach-disk  vm1 /var/lib/libvirt/dir_pool/vol1 vde   --sourcetype dir
error: Unknown source type: 'dir'

virsh attach-disk  vm1 /var/lib/libvirt/dir_pool/vol1 vde   --sourcetype file
error: Failed to attach disk
error: internal error unable to execute QEMU command '__com.redhat_drive_add': Device 'drive-virtio-disk4' could not be initialized

 virsh attach-disk  vm1 /var/lib/libvirt/dir_pool/vol1 vdb --type file
error: Failed to attach disk
error: internal error unknown disk device 'file'


virsh attach-disk vm1 /var/lib/libvirt/dir_pool/vol1 vde   --type dir
error: Failed to attach disk
error: internal error unknown disk device 'dir'

chrism01 · 09-02-2012, 11:49 PM

Ok; can't make attach-disk work; open to WORKING solns if anyone has them; it should be do-able.

In the meantime, edited vm

Code:

virsh edit vm1

then add stanza

    <disk type='file' device='disk'>
      <driver name='qemu' type='raw'/>
      <source file='/var/lib/libvirt/dir_pool/vol1'/>
      <target dev='vdb' bus='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
    </disk>

NB: don’t add bus field & address type rec; these are auto generated.
This works for anyone else who reads this, then you just restart vm, login and fdisk as usual.

PS I amended the container dir ownership/perms to match vm images dir

Code:

drwx--x--x. 2 root root  4096 Aug 30 11:56 images
drwx--x--x. 2 root root  4096 Aug 30 15:31 dir_pool

barghota · 09-04-2012, 05:23 AM

Chris,

Instead of 'vde' try 'hde' or 'sde', maybe your libvirtd version doesn't support it, what version is it?

chrism01 · 09-04-2012, 11:54 PM

Code:

 rpm -qa|grep virt
libvirt-python-0.9.10-21.el6.x86_64
virt-manager-0.9.0-14.el6.x86_64
libvirt-client-0.9.10-21.el6.x86_64
python-virtinst-0.600.0-8.el6.noarch
virt-viewer-0.5.2-9.el6.x86_64
virt-what-1.11-1.1.el6.x86_64
libvirt-0.9.10-21.el6.x86_64
virt-top-1.0.4-3.13.el6.x86_64

Anyway, as you can see from above, it accepts vdb happily in the xml & inside the VM

Code:

df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root
                       16G  6.2G  8.5G  43% /
tmpfs                 939M     0  939M   0% /dev/shm
/dev/vda1             485M   32M  429M   7% /boot
/dev/vdb1             9.2G  149M  8.6G   2% /data

barghota · 09-05-2012, 06:06 AM

Can you post the log file?

chrism01 · 09-09-2012, 11:31 PM

OK; just created a new vm and dir pool vol and it worked fine

Code:

virsh attach-disk vm3 /var/lib/libvirt/dir_pool/vol3 vdb

don't know why, but I'm not complaining

Maybe I had the previous vms shutdown at the time because I thought you had to do that?? Just guessing really...