vn(4) performance on 4.11 versus md(4) on 5.4
Glenn Dawson
glenn at antimatter.net
Sun Jun 5 06:38:50 GMT 2005
I have a number of systems running 4.11 that have file backed virtual
disks, each of which contains a jail. I need to start using 5.4 for new
servers. The catch is, file backed virtual disks using md(4) seem to be
much slower than similar virtual disks on 4.11 using vn(4). vn(4) on 4.11
is about 2.24 times faster than the equivalent setup using md(4) on 5.4.
I've posted the results of some tests that I ran at
http://www.antimatter.net/md-versus-vn.txt
Is this decrease in performance known? Is there something I can do in
order to come close to the performance that 4.11 has? I've tried changing
some of the parameters of the filesystem on the virtual disk, but the
performance didn't change.
I can supply more info than what the link above has, if needed.
If I should post this to another list please let me know. (I started here
in order to avoid cross posting.
-Glenn
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