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Hello,
Just to let you know, I also see very similar IDE-RAID0 performance
problems:
I have RAID0 with two 30G DiamondMax (Maxtor) ATA-66 drives connected to
a Promise Ultra66 controller.
I am using kernel 2.4.0-test1-ac15+B5 raid on a dual PII-450 with 256M
RAM (but have seen the same problems on all of the 2.3.XX series.
Here are the results from bonnie:
-------Sequential Output-------- ---Sequential Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
1200 6813 98.2 41157 42.0 10101 25.9 5205 78.9 14890 27.3 137.8 1.8
Here are the results from hdparm on my drives (just showing one because
they are identical):
/dev/hde:
Model=Maxtor 53073U6, FwRev=DA620CQ0, SerialNo=K604F9MC
Config={ Fixed }
RawCHS=4092/16/63, TrkSize=0, SectSize=0, ECCbytes=57
BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=off
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=60030432
IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 *udma4
/dev/hde:
multcount = 0 (off)
I/O support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 1 (on)
keepsettings = 0 (off)
nowerr = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 59554/16/63, sectors = 60030432, start = 0
Performance using 2.2.16 with raid+IDE patches gives very good
performance:
-------Sequential Output-------- ---Sequential Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
1200 6813 98.9 40923 40.7 15584 35.3 7154 97.6 40258 26.6 151.5 1.7
Here is my raidtab:
raiddev /dev/md0
raid-level 0
nr-raid-disks 2
persistent-superblock 1
chunk-size 32
device /dev/hdg2
raid-disk 0
device /dev/hde2
raid-disk 1
And here are single-disk and md0 performance tests using hdparm -tT:
/dev/hde:
Timing buffer-cache reads: 128 MB in 1.13 seconds =113.27 MB/sec
Timing buffered disk reads: 64 MB in 2.46 seconds = 26.02 MB/sec
/dev/md0:
Timing buffer-cache reads: 128 MB in 0.94 seconds =136.17 MB/sec
Timing buffered disk reads: 64 MB in 1.66 seconds = 38.55 MB/sec
Hope this helps sort the matter out...
Scott
--
Scott M. Ransom Address: Harvard-Smithsonian CfA
Phone: (617) 495-4142 60 Garden St. MS 10
email: [EMAIL PROTECTED] Cambridge, MA 02138
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