[RE] Poorer performance with Raid0 then without?

So the dma settings are normal. My only other thought is what do you have on /dev/hdf? Is that drive a slave with /dev/hde as the master? Can you run the system with hde and hdg but without hdf and see if the raid0 performance improves?

---------[ Received Mail Content ]----------

Subject : [RE] Poorer performance with Raid0 then without?

Date : Mon, 1 Jan 2007 11:24:31 -0800

From : "Listbox" <[email protected]>

To : <[email protected]>

Here is more hdparm data. It looks like bad news.

Note: for whatever reason, /dev/md0 does not seem to be my RAID device. I

set up my raid (via trial and error) with dmraid, and it gave me

/dev/mapper/sil_agbgdgbjfhei. I have always felt there was something

not-right about that.

Second, the errors hdparm reports from -tT look significant.

Finally, "Timing cached reads" are much lower then single drives. I don't

know what this really means in a RAID context.

I tried removing the third drive on the board (primary slave), no effect.

Anyway, given the errors, is this a RAID software problem, or a piece of

junk RAID adapter card?

Thanks so much, folks.

Listbox

* * * * * * * * * * *

* * * * * * * * * * *

/dev/hde:

multcount = 16 (on)

IO_support = 0 (default 16-bit)

unmaskirq = 0 (off)

using_dma = 1 (on)

keepsettings = 0 (off)

readonly = 0 (off)

readahead = 256 (on)

geometry = 19457/255/63, sectors = 312581808, start = 0

/dev/hdg:

multcount = 16 (on)

IO_support = 0 (default 16-bit)

unmaskirq = 0 (off)

using_dma = 1 (on)

keepsettings = 0 (off)

readonly = 0 (off)

readahead = 256 (on)

geometry = 19457/255/63, sectors = 312581808, start = 0

* * * * * * * * * * *

* * * * * * * * * * *

hprarm -tT /dev/md0

read() hit EOF - device too small

/dev/md0:

Timing buffered disk reads: read() hit EOF - device too small

BLKFLSBUF failed: No such device

HDIO_DRIVE_CMD(null) (wait for flush complete) failed: No such device

hprarm -tT /dev/mapper/sil_agbgdgbjfhei

/dev/mapper/sil_agbgdgbjfhei:

Timing cached reads: HDIO_DRIVE_CMD(null) (wait for flush complete)

failed: Inappropriate ioctl for device

1288 MB in 2.00 seconds = 643.22 MB/sec

Timing buffered disk reads: HDIO_DRIVE_CMD(null) (wait for flush complete)

failed: Inappropriate ioctl for device

284 MB in 3.01 seconds = 94.27 MB/sec

* * * * * * * * * * *

* * * * * * * * * * *

* * * * * * * * * * *

* * * * * * * * * * *

dev/hda:

Timing cached reads: 1668 MB in 2.00 seconds = 834.10 MB/sec

Timing buffered disk reads: 88 MB in 3.05 seconds = 28.87 MB/sec

/dev/hdb:

Timing buffered disk reads:

/dev/hdc:

Timing cached reads: 1696 MB in 2.00 seconds = 847.36 MB/sec

Timing buffered disk reads: 88 MB in 3.05 seconds = 28.82 MB/sec

/dev/hde:

Timing cached reads: 1680 MB in 2.00 seconds = 838.49 MB/sec

Timing buffered disk reads: 168 MB in 3.03 seconds = 55.46 MB/sec

/dev/hdf:

Timing cached reads: 1688 MB in 2.00 seconds = 843.57 MB/sec

Timing buffered disk reads: 164 MB in 3.00 seconds = 54.59 MB/sec

/dev/hdg:

Timing cached reads: 1696 MB in 2.00 seconds = 846.68 MB/sec

Timing buffered disk reads: 162 MB in 3.03 seconds = 53.45 MB/sec

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