I've decide to use mdadm RAID1(root) and RAID5(data) on my servers and my final choice of filesystem was EXT4 for both (did consider btrfs, XFS and ZFS, but looking at all pros/cons I ended up with EXT4).
I've started wondering about a few things in regards to performance optimizing:
Twice journal write:
If my QCOW2 file is located on a EXT4 filesystem on the host, and the filesystem in the QCOW2 is also EXT4, one could say journal would be written twice. Would it be safe to disable journal in QCOW2 disk? Would I still be protected in case of crash?
I assume using a Logical Volume (LVM) directly as quest disk wouldn't give me any additional "enhancement" in relation to journal and checksum, as LVM doesn't do neither, right.
But at least journaling would be written twice together with other filesystem overhead on the host.
EXT4 data checksum:
AFAIK EXT4 doesn't have data-checksum (only on metadate), but if EXT4 is located on a RAID5 volume would I get data-checksum, similar to e.g. ZFS, because of the RAID5 data checksum?
If so, what about RAID1, will that also give me data checksum?
I've started wondering about a few things in regards to performance optimizing:
Twice journal write:
If my QCOW2 file is located on a EXT4 filesystem on the host, and the filesystem in the QCOW2 is also EXT4, one could say journal would be written twice. Would it be safe to disable journal in QCOW2 disk? Would I still be protected in case of crash?
I assume using a Logical Volume (LVM) directly as quest disk wouldn't give me any additional "enhancement" in relation to journal and checksum, as LVM doesn't do neither, right.
But at least journaling would be written twice together with other filesystem overhead on the host.
EXT4 data checksum:
AFAIK EXT4 doesn't have data-checksum (only on metadate), but if EXT4 is located on a RAID5 volume would I get data-checksum, similar to e.g. ZFS, because of the RAID5 data checksum?
If so, what about RAID1, will that also give me data checksum?