2014-08-04 14:58 GMT+04:00 John Ferlan <jferlan@xxxxxxxxxx>: > On 08/02/2014 04:24 PM, Vasiliy Tolstov wrote: >> Hi all. I'm using libvirt 1.2.6 >> I want to use lvm storage for my virtual machines. >> But i want to use new lvm2 feature - thin pool. How can i do that in >> libvirt? If libvirt can't create it via pool xml, does (and how) to >> use this setup under libvirt? >> > > The 'Thin Pool' is avoided by libvirt, but volumes found a "Sparse" or > "Snapshot" that are part of an lvm thin pool can be utilized by libvirt > - although as the storage administrator understand that if the volume > becomes "filled" - it will go "Inactive" > > The key to whether an lvm volume is found is the attributes as seen from > the 'lvs' utility which spits out the following for example: > > # lvs > LV VG Attr LSize Pool Origin Data% Move > Log Cpy%Sync Convert > home fedora -wi-ao---- 136.72g > > root fedora -wi-ao---- 50.00g > > swap fedora -wi-ao---- 7.64g > > lv_test lv_pool swi-a-s--- 4.00m [lv_test_vorigin] 50.39 > > or for a filled and now inactive volume: > > # lvs > LV VG Attr LSize Pool Origin Data% Move > Log Cpy%Sync Convert > home fedora -wi-ao---- 136.72g > > root fedora -wi-ao---- 50.00g > > swap fedora -wi-ao---- 7.64g > > lv_test lv_pool swi-I-s--- 4.00m [lv_test_vorigin] 100.00 > > > The 'Attr' column must have an active volume as seen by the 'a' in the > 5th field and as Jan points out cannot be a "thin" pool as seen when > there's a 't' in the first column. > > Assuming you know have the physical volume already created (via > pvcreate), then a pool definition could be: > > # more lv_pool.xml > <pool type="logical"> > <name>lv_pool</name> > <source> > <device path="/dev/sdb2"/> > <device path="/dev/sdb3"/> > </source> > <target> > <path>/dev/lv_pool</path> > </target> > </pool> > # > > Where the device path entries would be your physical volumes. > > Using 'virsh pool-build lv_pool' and 'virsh pool-start lv_pool' will set > things up allowing for the creation of a volume in the pool such as: > > # more lv_test.xml > <volume> > <name>lv_test</name> > <key>r4xkCv-MQhr-WKIT-R66x-Epn2-e8hG-1Z5gY0</key> > <source> > <device path='/dev/sdb3'> > </device> > </source> > <capacity>8388608</capacity> > <allocation>4194304</allocation> > <target> > <path>/dev/lv_pool/lv_test</path> > <permissions> > <mode>0660</mode> > <owner>0</owner> > <group>6</group> > <label>system_u:object_r:fixed_disk_device_t:s0</label> > </permissions> > </target> > </volume> > > via 'virsh vol-create lv_pool lv_test.xml' where the 'capacity' and > 'allocation' values are the key to determining whether a 'sparse' or > 'snapshot' volume from an lvm thin pool will be created. If capacity is > not equal allocation, then the resulting libvirt command adds the > '--virtualsize' (or '--V') to the lvm command used to create the volume > in the pool, e.g. > > # /usr/sbin/lvcreate --name lv_test -L 4096K --virtualsize 8192K lv_pool > > John Very good doc. Thanks! -- Vasiliy Tolstov, e-mail: v.tolstov@xxxxxxxxx jabber: vase@xxxxxxxxx _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
