Disk cache settings for VMs on BTRFS

[croxis]

I'm a little confused with the documentation. The BTRFS page says

BTRFS will honor the O_DIRECT flag when opening files, meaning VMs should not use cache mode none, otherwise there will be checksum errors.

which I understand to mean set the disk cache to anything other than none.

However on the ZFS and Dir pages say that write back should be used instead of none if the storage does NOT support O_Direct.

What should I set my disk cache to for VMs on Proxmox 7? Thanks!

 

[mac.linux.free]

Good Question. testing btrfs, too.

 

[adoII]

Anyone found out what is the recommended setting of cache mode for vm images on btrfs ? none or writeback ?

 

[RolandK]

none is wrong, as none measn O_DIRECT, and that has known issues with btrfs