From b552aebbd471859172b36e16838ba73f148f1a47 Mon Sep 17 00:00:00 2001 From: Sebastien Boeuf Date: Mon, 7 Feb 2022 11:00:57 +0100 Subject: [PATCH] docs: Update snapshot/restore documentation Remove the bits about this feature being experimental, as well as limitations around virtio-mem and vhost-user devices. Signed-off-by: Sebastien Boeuf --- docs/snapshot_restore.md | 25 +++---------------------- 1 file changed, 3 insertions(+), 22 deletions(-) diff --git a/docs/snapshot_restore.md b/docs/snapshot_restore.md index 63a0a181d..72ce2e8f1 100644 --- a/docs/snapshot_restore.md +++ b/docs/snapshot_restore.md @@ -8,9 +8,6 @@ snapshot and creates the exact same virtual machine, restoring the previously saved states. The new virtual machine is restored in a paused state, as it was before the snapshot was performed. -This feature is important for the project as it establishes the first step -towards the support for live migration. - ## Snapshot a Cloud Hypervisor VM First thing, we must run a Cloud Hypervisor VM: @@ -46,18 +43,11 @@ ll /home/foo/snapshot/ total 4194536 drwxrwxr-x 2 foo bar 4096 Jul 22 11:50 ./ drwxr-xr-x 47 foo bar 4096 Jul 22 11:47 ../ --rw------- 1 foo bar 3221225472 Jul 22 11:19 memory-region-0 --rw------- 1 foo bar 1073741824 Jul 22 11:19 memory-region-1 +-rw------- 1 foo bar 4294967296 Jul 22 11:19 memory-ranges -rw------- 1 foo bar 217853 Jul 22 11:19 vm.json ``` -In this particular example, we can observe that 2 memory region files were -created. That is explained by the size of the guest RAM, which is 4GiB in this -case. Because it exceeds 3GiB (which is where we can find a ~1GiB memory hole), -Cloud Hypervisor needs 2 distinct memory regions to be created. Each memory -region's content is stored through a dedicated file, which explains why we end -up with 2 different files, the first one containing the guest RAM range 0-3GiB -and the second one containing the guest RAM range 3-4GiB. +`memory-ranges` stores the content of the guest RAM. `vm.json` gathers all information related to the virtual machine configuration and state. The configuration bits are used to create a similar virtual machine @@ -100,13 +90,4 @@ snapshot earlier. ## Limitations -The support of snapshot/restore feature is still experimental, meaning one -might still find some bugs associated with it. - -Additionally, some devices and features don't support to be snapshot and -restored yet: -- `vhost-user` devices -- `virtio-mem` -- Intel SGX - -VFIO devices are out of scope. +VFIO devices and Intel SGX are out of scope.