sluggish disk performance.

[Dan Nelson]

In the last episode (Aug 21), Chris Knipe said:
> Disks   ad0                               ofod            intrn
> KB/t  16.83                               %slo-z    35456 buf
> tps     103                             4 tfree       414 dirtybuf
> MB/s   1.70                                         20988 desiredvnodes
> % busy   98                                          5247 numvnodes
>                                                     4223 freevnodes
> 
> Got 1 ATA100 Seagate 120GB disk in there at the moment.... 1.7MB/s at
> 98% busy?  Surely, that figure is WAY low???  I'd expect atleast
> about 10MB/s on ATA100.

That number's about right for random I/O and small blocksizes, which is
what the KB/t field shows.  If you were doing sequential I/O, the KB/t
field would be at or near 128.  Are you also running a "du", "cvs
update", or other command likely to be doing random disk accesses?

-- 
	Dan Nelson
	dnelson at allantgroup.com