UPDATE: disk speed issues

I got one response from BOB: The CX300 has write cache. The internal
disks do not. What you are seing is expected. Nothing is wrong. The
CX300 writes faster than the internal disks.


i did some more experimenting. (each script is moving a big file from
originatingdisk@xxxxxxxxxxxxxxxxxx)

as you can see moving files from the external SAN disk onto the Server
disks takes much longer than even writing between internal disks
(server2server). is this expected?

thanks,

abhimanyu.

# time ./server2san.sh
0.26u 8.27s 0:08.89 95.9%

# time ./san2server.sh
0.31u 7.55s 0:26.77 29.3%

# time ./san2san.sh
0.31u 8.15s 0:08.96 94.4%

# time ./server2server.sh
0.32u 5.83s 0:06.19 99.3%





________________________________

From: Bob [mailto:wick@xxxxxxxxxxx]
Sent: Friday, March 24, 2006 5:40 PM
To: Pandey, Abhimanyu
Subject: Re: disk speed issues


The CX300 has write cache. The internal disks do not. What you are
seing is expected. Nothing is wrong. The CX300 writes faster than the
internal disks.


---------- Original Message -----------
From: "Pandey, Abhimanyu" <apandey@xxxxxxxxxxxxx>
To: <sunmanagers@xxxxxxxxxxxxxxx>
Sent: Fri, 24 Mar 2006 15:44:00 -0500
Subject: disk speed issues

hello All,

I am continuing to build by sunfire box with a cx300 san array.

unfortunately everything is fine except for very different data
transfer
times

when I move a file (big *.Z file) from internal disk to the array it
completes in about 9 seconds.

when I move the same file back from array to internal disk it takes
about 27 seconds.

# time ./server2san.sh
0.29u 8.18s 0:09.42 89.9%
# time ./san2server.sh
0.30u 7.54s 0:28.08 27.9%
#

any ideas would be very much appreciated.

thanks,

abhimanyu.

Abhimanyu Pandey
Information Technologies
Worcester State College
508-929-8913

guruspeak:"...the journey IS the destination..."
geekspeak:"...the network IS the computer..."
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------- End of Original Message -------
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