Loading docs/user/source/libvirt.rst 0 → 100644 +67 −0 Original line number Diff line number Diff line Libvirt hot migration compatibility ----------------------------------- Should work: From 0.8.8 to 0.9.8 From 0.9.8 to 0.9.12 Should not work: From 0.9.12 to 0.9.8 (because of bad xml seclabel, event if set explicitly it doesn't work) From 0.9.8 to 0.8.8 (because of XML format compat) Note for all versions: When migrating, libvirt try to acquire some mutex on the domain and this can block forever (0.8.8) or timeout (0.9.8 and +). Take a look at the node logs to be sure. In the later case, you must restart libvirt in order for the migration to work properly. What to do when live migration fails ------------------------------------ Check DRBD and remove if needed: :: # identify which DRBD volume needs to go down it-test-15.lab.fr.lan ~ 0 # cat /proc/drbd version: 8.3.9 (api:88/proto:86-95) srcversion: CF228D42875CF3A43F2945A 0: cs:Connected ro:Primary/Primary ds:UpToDate/UpToDate C r----- ns:2097152 nr:0 dw:0 dr:2097352 al:0 bm:128 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:0 # identify all LV (VM, copy and DRBD meta) it-test-15.lab.fr.lan ~ 0 # dmsetup ls vg-Test--Clone--root (253, 5) vg-Test--Clone--root.copy (253, 2) vg-Test--Clone--root.drbdmeta (253, 1) vg-Etherpad--Etherpad (253, 0) # reload VM LV table if needed it-test-15.lab.fr.lan ~ 0 # dmsetup table vg-Test--Clone--root.copy | dmsetup load vg-Test--Clone--root it-test-15.lab.fr.lan ~ 0 # dmsetup suspend vg-Test--Clone--root it-test-15.lab.fr.lan ~ 0 # dmsetup resume vg-Test--Clone--root # halt DRBD volume it-test-15.lab.fr.lan ~ 0 # drbdsetup /dev/drbd0 disconnect it-test-15.lab.fr.lan ~ 0 # drbdsetup /dev/drbd0 secondary it-test-15.lab.fr.lan ~ 0 # drbdsetup /dev/drbd0 detach it-test-15.lab.fr.lan ~ 0 # drbdsetup /dev/drbd0 down # remove copy DM it-test-15.lab.fr.lan ~ 0 # dmsetup remove vg-Test--Clone--root.copy # remove DRBD meta it-test-15.lab.fr.lan ~ 0 # lvremove /dev/vg/Test-Clone-root.drbdmeta # /!\ on hypervisor where the VM is not present, also remove the VM LV it-test-15.lab.fr.lan ~ 0 # lvremove /dev/vg/Test-Clone-root # check that libvirt ended the qemu process # refresh libvirt pools it-test-15.lab.fr.lan ~ 0 # virsh pool-refresh vg Loading
docs/user/source/libvirt.rst 0 → 100644 +67 −0 Original line number Diff line number Diff line Libvirt hot migration compatibility ----------------------------------- Should work: From 0.8.8 to 0.9.8 From 0.9.8 to 0.9.12 Should not work: From 0.9.12 to 0.9.8 (because of bad xml seclabel, event if set explicitly it doesn't work) From 0.9.8 to 0.8.8 (because of XML format compat) Note for all versions: When migrating, libvirt try to acquire some mutex on the domain and this can block forever (0.8.8) or timeout (0.9.8 and +). Take a look at the node logs to be sure. In the later case, you must restart libvirt in order for the migration to work properly. What to do when live migration fails ------------------------------------ Check DRBD and remove if needed: :: # identify which DRBD volume needs to go down it-test-15.lab.fr.lan ~ 0 # cat /proc/drbd version: 8.3.9 (api:88/proto:86-95) srcversion: CF228D42875CF3A43F2945A 0: cs:Connected ro:Primary/Primary ds:UpToDate/UpToDate C r----- ns:2097152 nr:0 dw:0 dr:2097352 al:0 bm:128 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:0 # identify all LV (VM, copy and DRBD meta) it-test-15.lab.fr.lan ~ 0 # dmsetup ls vg-Test--Clone--root (253, 5) vg-Test--Clone--root.copy (253, 2) vg-Test--Clone--root.drbdmeta (253, 1) vg-Etherpad--Etherpad (253, 0) # reload VM LV table if needed it-test-15.lab.fr.lan ~ 0 # dmsetup table vg-Test--Clone--root.copy | dmsetup load vg-Test--Clone--root it-test-15.lab.fr.lan ~ 0 # dmsetup suspend vg-Test--Clone--root it-test-15.lab.fr.lan ~ 0 # dmsetup resume vg-Test--Clone--root # halt DRBD volume it-test-15.lab.fr.lan ~ 0 # drbdsetup /dev/drbd0 disconnect it-test-15.lab.fr.lan ~ 0 # drbdsetup /dev/drbd0 secondary it-test-15.lab.fr.lan ~ 0 # drbdsetup /dev/drbd0 detach it-test-15.lab.fr.lan ~ 0 # drbdsetup /dev/drbd0 down # remove copy DM it-test-15.lab.fr.lan ~ 0 # dmsetup remove vg-Test--Clone--root.copy # remove DRBD meta it-test-15.lab.fr.lan ~ 0 # lvremove /dev/vg/Test-Clone-root.drbdmeta # /!\ on hypervisor where the VM is not present, also remove the VM LV it-test-15.lab.fr.lan ~ 0 # lvremove /dev/vg/Test-Clone-root # check that libvirt ended the qemu process # refresh libvirt pools it-test-15.lab.fr.lan ~ 0 # virsh pool-refresh vg
