The disk became slower after the snapshot

vadimushka

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May 26, 2020
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Testing the version 6.2-4. I created a virtual machine virtIO SCSI. The hard disk is scsi qcow2. I checked the disk using CristalDisk, the speed is good, over the network, too. I took a snapshot of the VM, and then the disk speed plummeted. Can you tell me what the problem might be?
 
Can you tell me what the problem might be?
Without knowing how much the difference is. It is expected that snapshots slow down IO, as more data changes. Also qcow2 on a filesystem introduces another layer of writes, in contrast to directly using LVM-thin or ZFS. But of course they also come with their limitations.