Thank you, Jithin.
Marty From: Jithin Raju <[email protected]> Date: Wednesday, November 5, 2025 at 11:50 PM To: [email protected] <[email protected]> Subject: Re: KVM, Snapshots, and QCOW2 WARNING: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe. Hi Marty, Its about instance snapshots right, can try using 4.21/4.22 ( once its available) , apparently this is improved in 4.21 : https://docs.cloudstack.apache.org/en/latest/adminguide/virtual_machines.html#pause-during-live-instance-snapshots-on-kvm -Jithin From: Marty Godsey <[email protected]> Date: Thursday, 6 November 2025 at 3:13 AM To: [email protected] <[email protected]> Subject: KVM, Snapshots, and QCOW2 Hello, On my KVM cluster, which is new and not in production yet since I am still tuning, I noticed that snapshots were taking a long time to complete. And when say a long time, I mean 45seconds to 1 min. The VM is, of course, paused when this happens. As you can imagine, this is unusable. The connection to the NFS storage is 100G and all NVME. While a snapshot is running, I can see it hitting the storage really hard. I then looked at the KVM process for that VM on the KVM server and it looks like it is using RAW for the format. I created this VM by spinning up a new VM in CloudStack so I could make my template. So I have a couple questions. How do I specify QCOW2 when making new volumes or spinning up new VMs and I assume that snapshots should not take this long, correct? Thank you for all your help.
