Areca Raid 6 ARC-1231 Raid 6 Slow LS Listing Performance on large directory

[Adrian Chadd]

2008/6/12 Paul <bsdlist at cogeco.ca>:

> 1) When I do a ls -lh on the raid 6 array with 6 disks in the array it takes
> aver 16 seconds before it starts to display anything on the screen.
> 2) While running a tar command on another shell, the time goes to 28 seconds
> for the same list to start showing.
> 3) When I do a ls (with no other options) it starts to list right away.
> 4) When I do a ls -ln it displays right away as well  pointing to the
> slowdown being the mapping of the users in the db lookup.
>
> I have the same directory with the same number of files on a Raid 5 SCSI
> partition on Freebsd 4.X and it only takes 2 seconds to start displaying the
> list with the command ls -lh.
>
> Any ideas why it takes so long for this on Freebsd 7.0 stable?
>
> The partition this folder is on it /dev/da0s1f  with a total size of 1.7T
>  and a usage of  63G
>
> Any suggestions or help on this would be greatly appreciated.

Could you please do a couple of other tests, if you're able to? I've
got a PR to look into this issue.

Could you see if using a smaller password file makes the ls start/run quicker?

Could you possibly run ls inside "truss" on both FreeBSD-4 and
FreeBSD-7 and email me a snippet of the output (say, a few hundred
lines) ? Something like:

truss ls <flags> >foo 2>&1

Thanks,



Adrian

-- 
Adrian Chadd - adrian at freebsd.org