Re: RAID-1 performance under 2.4 and 2.6

[Bart Van Assche]

On Tue, Mar 25, 2008 at 7:43 PM, Emmanuel Florac <eflorac@xxxxxxxxxxxxxx> wrote:
>
>  dd if=/dev/zero of=/mountpoint/testfile bs=1M count=1024

Keep in mind that the above test tests two subsystems at the same
time: RAID-1 + the filesystem on top of it. If you want to test RAID-1
performance you should specify a raw device to of=... instead of a
file (and the direct I/O flags). There are considerable performance
differences between filesystems for large files. E.g. XFS is a lot
faster than ext3 for large files (gigabytes).

Bart.
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