[Qemu-stable] [Help] QCOW2 Snapshot Stability

[Halsey Pian]

Dear All,

 

Nice to know all of you!

 

Recently, I am reading codes of QCOW2 format, in order to switch virtualization solution in my project from VMWare to KVM for more specific customization based on customer's requirements.

 

I have one consideration related to QCOW2 format in QEMU.

 

As we know there are two modes for snapshot in QCOW2 img format,

1.       Internal mode. All snapshots and original img data in one file

2.       External mode. Using backing file to create snapshot to save the snapshot data to one separate file

 

Could you share some info related to the stability for this two modes? Which one is recommended?

For the first all-in-one mode, maybe we would get a huge file, and maybe we cannot use this img if it is broken due to some reason/exception caused by read/write during long term running especially for server domain.

For the second mode, I have finished some basic test, not see any issue by now, not know if there is potential risk.

 

Could you provide help on it? Many thanks!

 

 

 

Best Regards

Halsey Pian