[Qemu-discuss] drive cache=writethrough without flushing to physical disks OR drive cache=none with readonly host cache

[Stanislav German-Evtushenko]

Hello,

As I understand so far:
- cache=writethrough - uses host cache readonly and flushes all data to disks directly (avoid RAID cache)
- cache=none - doesn't use host cache at all and written data goes to the RAID cache (if one exists)

However there is no such a cache mode that lie in between:
- uses host cache for reading and RAID cache for writing (without writing to host cache)

Is there any reason not to have such a cache or am I missing something?

Best regards,
Stanislav