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Some of these are fair points but zfsonlinux/OpenZFS has had O_DIRECT since 0.8.x.
by tomatocracy 5y ago
Some of these are fair points but zfsonlinux/OpenZFS has had O_DIRECT since 0.8.x.
- tobias3 5y agoZFSOnLinux just ignores the O_DIRECT flag if I remember correctly. Granted, this is what btrfs should do by default as well since there is an ugly issue where software can modify the O_DIRECT buffer after it was submitted causing btrfs checksum errors even though nothing was corrupted (and there is nothing to be done about it except disabling O_DIRECT or creating a buffer copy).
- tomatocracy 5y agoYes (and as you mention this is the right thing to do) but I think it means that the Linux kernel will bypass the page cache which is still useful.