From: Renaud, Andre (andre.renaud@hp.com)
Date: Sun Jun 29 2003 - 21:23:03 EDT
I know this group doesn't deal directly with the HSG80 San controllers, but I thought a few of you might have some idea about this. We have a SAN attached Tru64 5.1 machine that isn't performing quite as we'd expect. We've run the "VTDPY" program on the controllers and it appears as if it is getting poor cache hit performance. The output from "display cache" is as follows:
HSG80 S/N: XXXXXXXXXX SW: V87S-0 HW: E-14 30-JUN-2003 13:2
0.0% Idle 10886 KB/S 906 Rq/S Up: 155 0:48
Unit ASWC KB/S Rd% Wr% Cm% HT% PH% MS% Purge BlChd BlHit RH%
D0000 o^ a 10567 97 2 0 10 0 90 119600 121168 15296 11
D0001 o^ a 27 18 81 0 0 0 100 160 352 0 0
D0002 o^ a 0 0 0 0 0 0 0 0 0 0 0
D0003 o^ a 99 17 82 0 21 0 79 336 1232 48 0
D0004 o^ a 0 0 0 0 0 0 0 0 0 0 0
D0005 o^ a 192 67 32 0 17 0 83 1600 2368 288 8
D0006 o^ a 0 0 0 0 0 0 0 0 0 0 0
D0007 o^ a 0 0 0 0 0 0 0 0 0 0 0
D0008 o^ a 0 0 0 0 0 0 0 0 0 0 0
If you look at Unit D0000 the cache miss % is around 90%.
My question is, does anyone know where else I could look to confirm our suspicion that the performance is cache related? We suspect the application is requesting data in quite a random way off the disk, but we need some more information to present our case on it.
Thanks,
Andre
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