About virsh(1) and Postcopy migration
by Prasad Pandit
Hello,
* virsh(1) offers multiple options to initiate Postcopy migration:
1) virsh migrate --postcopy --postcopy-after-precopy
2) virsh migrate --postcopy + virsh migrate-postcopy
3) virsh migrate --postcopy --timeout <N> --timeout-postcopy
When Postcopy migration is invoked via options (2) or (3) above, the migrated guest on the destination host hangs sometimes. But such a hang is not reproducible with option (1) above.
* When using option (1) above, libvirtd(8) waits for the first pass of pre-copy to finish before enabling postcopy migration.
* Does the same waiting happen when using options (2) and (3) above?
===
2024-07-24 14:16:27.448+0000: msg={"execute":"migrate"
2024-07-24 14:16:29.318+0000: msg={"execute":"migrate-start-postcopy"
2024-07-24 14:28:39.737+0000: msg={"execute":"migrate"
2024-07-24 14:28:41.119+0000: msg={"execute":"migrate-start-postcopy"
2024-07-24 14:44:11.684+0000: msg={"execute":"migrate"
2024-07-24 14:44:12.835+0000: msg={"execute":"migrate-start-postcopy"
2024-07-24 14:48:00.675+0000: msg={"execute":"migrate"
2024-07-24 14:48:02.319+0000: msg={"execute":"migrate-start-postcopy"
2024-07-24 15:03:36.110+0000: msg={"execute":"migrate"
2024-07-24 15:03:37.341+0000: msg={"execute":"migrate-start-postcopy"
2024-07-24 16:05:25.602+0000: msg={"execute":"migrate"
2024-07-24 16:05:26.756+0000: msg={"execute":"migrate-start-postcopy"
===
* While running migration tests with options (2) and (3) above, switch to postcopy appears to happen within 2 seconds of starting migration.
- Is that reasonable time to switch from pre-copy to postcopy?
- Is there an ideal time to wait before switching to postcopy?
* The feature page below suggests to wait until one cycle of RAM migration has completed
-> https://wiki.qemu.org/Features/PostCopyLiveMigration
* I'd much appreciate any clarification/confirmation about this.
Thank you.
---
-Prasad
1 week, 5 days
- 2
- 1
Possible issue with shared folder from host to virtual machine
by Mulloch94＠protonmail.com
I ran into an issue when trying to connect a shared folder from my host to my virtual OS in KVM. The folder actually does appear in the virtual OS, but it's empty, unlike the folder in the host which has files in it. I'm not ruling out the possibility that I configured something wrong, but the instructions on setting it up seemed to be pretty straightforward. Basically I did the following procedures:
mkdir ~/shared
chmod 777 ~/shared
Went to VirtManager enabled shared memory, added FileSystem with driver virtiofs. My source path to find the folder was /home/username/shared and the target path was /mnt/shared.
Upon booting the virtual machine everything seemed to work. I found the folder where it should be, only there was nothing in it. And on the host there was files I had already placed in the folder. So this is where I'm at now.
1 week, 5 days
- 1
- 0
- ← Newer
- 1
- Older →