diff --git a/howto/ganeti.md b/howto/ganeti.md index 1bd62b8c76368010b7b32674b7ebb699e24afdc3..26664bedc7711ed3f61ad99222e1cee65d733279 100644 --- a/howto/ganeti.md +++ b/howto/ganeti.md @@ -1327,7 +1327,17 @@ This will only migrate the VMs without rebooting the hosts: ./reboot --ganeti-migrate-back --kind=cancel -v --reason 'qemu flagged in needrestart' \ -H fsn-node-0{1,2,3,4,5,6,7,8}.torproject.org -This should cause no user-visible disruption. +This should cause no user-visible disruption, as it migrates all the +VMs around and back. + +That should reset the Qemu processes across the cluster and refresh +the libraries Qemu depends on. + +If you actually need to restart the instances in place (and not +migrate them), you need to use the `--skip-ganeti-empty` flag instead: + + ./reboot --skip-ganeti-empty --kind=cancel -v --reason 'qemu flagged in needrestart' \ + -H dal-node-0{1,2,3}.torproject.org ## Rebalancing a cluster @@ -3123,6 +3133,7 @@ gnt-cluster modify -H kvm:disk_type=scsi-hd gnt-cluster modify -H kvm:migration_bandwidth=950 gnt-cluster modify -H kvm:migration_downtime=500 gnt-cluster modify -H kvm:migration_caps=postcopy-ram +gnt-cluster modify -H kvm:cpu_type=host gnt-cluster modify -D drbd:c-plan-ahead=0,disk-custom='--c-plan-ahead 0' gnt-cluster modify --uid-pool 4000-4019 ``` @@ -3298,7 +3309,7 @@ emulation system to the CPU on the node. But that might make the live migration more brittle: VMs or processes can crash after a live migrate because of a slightly different configuration (microcode, CPU, kernel and QEMU versions all play a role). So we need to find the -lowest common demoninator in CPU families. The list of available +lowest common denominator in CPU families. The list of available families supported by QEMU varies between releases, but is visible with: @@ -3337,6 +3348,8 @@ to be verified. Nodes could also [grouped](http://docs.ganeti.org/docs/ganeti/3.0/html/man-gnt-group.html) to limit (automated) live migration to a subset of nodes. +Update: this was enabled in the `gnt-dal` cluster. + References: * <https://dsa.debian.org/howto/install-ganeti/>