Messages in this thread |  | | From | Marvin Justice <> | Subject | Re: Tuning Linux for high-speed disk subsystems | Date | Fri, 16 Nov 2001 10:53:05 -0600 |
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> As I count your disks may be the double for the best case. I read here on > LKML a post that someone claims that W2k deliever 250 MB/s with such a > configuration. Linux 2.4 should do the same. Ask the SCSI gurus. >
That may have been my post you refer to. With 2x5 disks, each capable of 50 MB/s by itself, we can stream 255 MB/s very smoothly in either direction with W2K --- as long as FILE_FLAG_NOBUFFER is used. With standard reads the number is more like 100 MB/s if I recall correctly, so the buffer cache can definitely get in the way.
With Linux + XFS I was getting 250 MB/s read and 220 MB/s write (with a bit less smoothness than W2K) using O_DIRECT and no high mem to avoid bounce buffer copies. Using standard reads the numbers drop to around 120 MB/s. That was a couple of weeks ago and I want to try tweaking some more but a co-worker has "borrowed" pieces of the hardware for the moment.
-- Marvin Justice Software Developer BOXX Technologies www.boxxtech.com mjustice@boxxtech.com 512-235-6318 (V) 512-835-0434 (F) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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