On Thu, Oct 30, 2003 at 04:17:45PM +0200, Craig Main wrote: > Hi all, [..]
Figured I'd chime in here with my own question. I have software RAID0
set up on my / partition across hda and hdb, should the throughput of
the raid on /dev/md0 be basically double the throughput of the
individual disk?
IE:
phoenix warez # hdparm -tT /dev/hda /dev/hdb /dev/md0
/dev/hda:
Timing buffer-cache reads: 1652 MB in 2.00 seconds = 826.00 MB/sec
Timing buffered disk reads: 84 MB in 3.03 seconds = 27.72 MB/sec
/dev/hdb:
Timing buffer-cache reads: 1664 MB in 2.00 seconds = 832.00 MB/sec
Timing buffered disk reads: 94 MB in 3.03 seconds = 31.02 MB/sec
/dev/md0:
Timing buffer-cache reads: 1652 MB in 2.00 seconds = 826.00 MB/sec
Timing buffered disk reads: 136 MB in 3.03 seconds = 44.88 MB/sec
Shouldn't /dev/md0 be a bit faster, basically 50-60MB/sec? My drives
and raid config look like the following, any suggestions on getting
100MB/sec like another poster here with RAID0 would be appreciated :)
I'd guess it's either overhead or I don't have the proper 133 cables on
my drives (pretty sure I do though) or something like that. This is on
an A7N8X-DX board with IDE hard drives, agpgart with nvidia support
built into the kernel, dma on by default in the kernel.
phoenix warez # cat /etc/raidtab
raiddev /dev/md0
raid-level 0
nr-raid-disks 2
nr-spare-disks 0
persistent-superblock 1
chunk-size 32
device /dev/hdb1
raid-disk 0
device /dev/hda6
raid-disk 1
phoenix warez # hdparm -i /dev/hda /dev/hdb
/dev/hda:
Model=Maxtor 54098H8, FwRev=DAC10SC0, SerialNo=K80JJDFC
Config={ Fixed }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=16
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=80041248
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
UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5
AdvancedPM=yes: disabled (255) WriteCache=enabled
Drive conforms to: ATA/ATAPI-6 T13 1410D revision 0:
* signifies the current active mode
/dev/hdb:
Model=Maxtor 52049H3, FwRev=JAC61HU0, SerialNo=F3H0HWFC
Config={ Fixed }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=16
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=40021632
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
UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5
AdvancedPM=yes: disabled (255) WriteCache=enabled
Drive conforms to: ATA/ATAPI-6 T13 1410D revision 0:
* signifies the current active mode
phoenix warez # hdparm /dev/hda /dev/hdb
/dev/hda:
multcount = 16 (on)
IO_support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 1 (on)
readonly = 0 (off)
readahead = 255 (on)
geometry = 4982/255/63, sectors = 80041248, start = 0
/dev/hdb:
multcount = 16 (on)
IO_support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 1 (on)
readonly = 0 (off)
readahead = 255 (on)
geometry = 39704/16/63, sectors = 40021632, start = 0
Any hints appreciated.
alan
--
Alan <[EMAIL PROTECTED]> - http://arcterex.net
--------------------------------------------------------------------
"There are only 3 real sports: bull-fighting, car racing and mountain
climbing. All the others are mere games." -- Hemingway
signature.asc
Description: Digital signature
