[rescue] Drive speed test

Dave McGuire mcguire at neurotica.com
Tue Mar 15 13:47:10 CDT 2016

  This test isn't looking at drive performance, it's looking at the
performance of the entire filesystem layer.  Most of the I/O you'll be
doing there is cached.  Use a raw device to check this for real.  Don't
write to a raw device containing a filesystem whose contents you care
about. ;)


On 03/15/2016 02:44 PM, CLIFFORD HAIGHT wrote:
> so how accurate are the values if I do
> time sh -c "dd if=/dev/null of=/tmp/tempfile bs=1024 count=10240"
> then
> time sh -c "dd if=/tmp/tempfile of=/dev/null bs=1024 count=10240"
> When running this on  the in Solaris 8 from openwidows, I got 1.2 write and .2
> read consistently
> When running on inside CDE I got something like 9.8-10.2s for write as I
> recall
> This is using the SCSI to SD adapter
> On a different SparcStation running SunOS4 I got the same read speed but about
> half as much write speed.
> This is using 1.2GB 5400rpm conner "SUN1.02" drive.
> Both these value seem beyond the capability if SCSI-2 controller.    When I
> did run the test in CDE I had a CD mounted, where as the other two instances
> had no other drives mounted.
> Does having other device mounted really effect disk throughput that much?
> I have a sunswift card  and a 711 enclosure that I haven't tested yet.  Would
> using  this card affect disk speed of internal drive at all.
> _______________________________________________
> rescue list - http://www.sunhelp.org/mailman/listinfo/rescue

Dave McGuire, AK4HZ
New Kensington, PA

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