Messages in this thread | | | Date | Mon, 13 Feb 2006 22:36:07 -0500 | From | Mark Lord <> | Subject | Re: default hdparms? readahead=256? Re: WD 400GB xATA Drives |
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Linda Walsh wrote: >.. > set to known values may not contain "great values". My "readahead" > value seems to boot with a value of "256" for all of my drives. > > Is this not a bit "excessive"?
Wow.. that does look a bit HUGE. Thanks for pointing it out, I'm resetting mine back to 128 for now.
> Justin Piszcz wrote: >> When I write to this disk for a while, I see this in dmesg (only once >> so far): >> >> [31230.223504] ata6: translated ATA stat/err 0x51/04 to SCSI >> SK/ASC/ASCQ 0xb/00/00 >> [31230.223511] ata6: status=0x51 { DriveReady SeekComplete Error } >> [31230.223515] ata6: error=0x04 { DriveStatusError } >> >> Is there some sort of smart testing going on constantly? I only get >> 26-27MB/s on this 400GB/SATA/16MB/7200RPM drive. I use smartmontools >> to do a daily test. However, even with smart disabled, I get: >> >> # hdparm -t /dev/sde >> /dev/sde: >> Timing buffered disk reads: 78 MB in 3.06 seconds = 25.46 MB/sec >> >> Does anyone know if this drive has problems in Linux or something? >> >> [ 6.895914] Vendor: ATA Model: WDC WD4000KD-00N Rev: 01.0 ...
Some drives suck at sequential reads, in favour of doing random seeks very very well. Basically, the on-drive seek algorithm may not favour doing much read-ahead. Try "hdparm -A1" and see if that helps. - 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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