Date: Sat, 29 Oct 2005 01:00:36 +0200 From: =?ISO-8859-1?Q?S=F8ren_Schmidt?= <sos@FreeBSD.ORG> To: Mikhail Teterin <mi+mx@aldan.algebra.com> Cc: Peter Jeremy <PeterJeremy@optushome.com.au>, hackers@FreeBSD.ORG, hardware@FreeBSD.ORG Subject: Re: Very slow writing to SATA disk Message-ID: <6F8F4C0A-1D7C-42FF-9CCB-C582827A5D2B@FreeBSD.ORG> In-Reply-To: <200510281841.19751.mi%2Bmx@aldan.algebra.com> References: <200510280518.j9S5I3oQ025430@blue.virtual-estates.net> <200510281803.15734.mi%2Bmx@aldan.algebra.com> <D64EDD7D-644E-4DCD-8B99-450403234A5D@FreeBSD.ORG> <200510281841.19751.mi%2Bmx@aldan.algebra.com>
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On 29/10/2005, at 0:41, Mikhail Teterin wrote: >> Look in smartmontools I provided patches for that, its not rocket >> science you know... >> > > This attitude -- on top of the API change itself -- is not really =20 > encouraging > for ISVs, you know :-) Sigh, ataidle is a hack and the author had no intention to listen =20 back when, so I dont feel teribly sorry about it you know. Spinning =20 down disks needs to be done at the driver level so ATA knows what =20 state the disk is in etc... > >> You need to find out what the transfer rates are for the RAW disk, ie >> by doing a dd from /dev/zero to the disk with a a resonable blocksize >> say 1M to minimize overhead. Also read speed from disk to /dev/null >> blocksize 1M would be helpfull. >> > > The read test averaged 62603828 bytes/sec over a minute or so. > The write test is only 6931231 bytes/sec -- about 9 times less. > > While dd is running, `systat 1 -vm' reports about 110 ata-=20 > interrupts (irq 25) > per second during the write test, and about 1000 during the read test. Hmm, that does sound as problems with that disk, or maybe disk vs =20 diskcontroller. Any chance you could try the disk on something else ? One other thing, how much mem do you have in there ? more than 4G and =20= bounce buffering might get into the picture ruining the transfer rate... S=F8ren Schmidt sos@FreeBSD.org
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