Date: Sat, 14 Feb 2009 08:29:53 +0100 From: Sebastiaan van Erk <sebster@sebster.com> To: Dieter <freebsd@sopwith.solgatos.com> Cc: freebsd-performance@freebsd.org Subject: Re: Extremely slow write speeds to disk : FreeBSD 7.1 and Dell SAS 6/iR Adapter Message-ID: <499672F1.4060109@sebster.com> In-Reply-To: <200902210616.GAA14352@sopwith.solgatos.com> References: <200902210616.GAA14352@sopwith.solgatos.com>
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[-- Attachment #1 --] Dieter wrote: >>> But the issue is that writing to disk is extremely slow...i.e. 14Mb per >>> second.... >>> >>> If I install any other linux distribution, like CentOS, write speek is >>> the way it should be..it averages around 190Mb+ per second >>> >>> I was hoping if it were at all possible for you to assist me in with a >>> later RAID Controller Driver for the SAS 6/iR Adapter >>> >> Try: >> hw.mpt.enable_sata_wc=1 >> in /boot/loader.conf and reboot. >> >> Assuming you are using SATA drives, the write cache is disabled by >> default. This reenables it. The mpt manpage holds more information. >> > > Just keep in mind that turning the disk's write cache on puts your > data at risk. :-( > > The correct solution is NCQ. Just wondering, if you have a battery on your RAID array, is this a problem? Wouldn't the cache get written anyway in case of a crash? Regards, Sebastiaan [-- Attachment #2 --] 0 *H 01 0 + 0 *H Q00lS| 6$1-~j0 *H 0b1 0 UZA1%0#U Thawte Consulting (Pty) Ltd.1,0*U#Thawte Personal Freemail Issuing CA0 080630135157Z 090630135157Z0h10Uvan Erk10U* Sebastiaan10USebastiaan van Erk1"0 *H sebster@sebster.com0"0 *H 0 Va\bEnݚa<M8ʄ^tv>x73bohi2oqS_¶Bm^p* I x"9 pt!j ar#)n)^? 'z<).+Ѐ4ig R'UP*\Ւ ,?.;?f BܯTzM IDվCK*3Yŧ mcaztxʐsq/ 00.0 U 0sebster@sebster.com0 U 0 0 *H KT4W6ӽq] tS` %f1 G:H b zJj$EjE'JV~-VbVnJZ E/`@@04!+T: c پf`$Z=1#|oG[OB RG00lS| 6$1-~j0 *H 0b1 0 UZA1%0#U Thawte Consulting (Pty) Ltd.1,0*U#Thawte Personal Freemail Issuing CA0 080630135157Z 090630135157Z0h10Uvan Erk10U* Sebastiaan10USebastiaan van Erk1"0 *H sebster@sebster.com0"0 *H 0 Va\bEnݚa<M8ʄ^tv>x73bohi2oqS_¶Bm^p* I x"9 pt!j ar#)n)^? 'z<).+Ѐ4ig R'UP*\Ւ ,?.;?f BܯTzM IDվCK*3Yŧ mcaztxʐsq/ 00.0 U 0sebster@sebster.com0 U 0 0 *H KT4W6ӽq] tS` %f1 G:H b zJj$EjE'JV~-VbVnJZ E/`@@04!+T: c پf`$Z=1#|oG[OB RG0?0 0 *H 01 0 UZA10U Western Cape10U Cape Town10U Thawte Consulting1(0&U Certification Services Division1$0"UThawte Personal Freemail CA1+0) *H personal-freemail@thawte.com0 030717000000Z 130716235959Z0b1 0 UZA1%0#U Thawte Consulting (Pty) Ltd.1,0*U#Thawte Personal Freemail Issuing CA00 *H 0 Ħ<UsUNʙZ hup [v :aQP 0cZ,p+Z?qV˯< 6$*+w=+>@dקe*TH<a@ dr` 00U 0 0CU <0:08642http://crl.thawte.com/ThawtePersonalFreemailCA.crl0 U 0)U "0 0 10UPrivateLabel2-1380 *H HP . fgCL!6 -6/ P p<ab:~ t%Pb'qW%ݩ9 Oe_N4[5MwV!x!5$ F]_eO1q0m0v0b1 0 UZA1%0#U Thawte Consulting (Pty) Ltd.1,0*U#Thawte Personal Freemail Issuing CAS| 6$1-~j0 + 0 *H 1 *H 0 *H 1 090214072953Z0# *H 1SV^BA商hmaߵ$0_ *H 1R0P0 `He0 *H 0*H 0 *H @0+0 *H (0 +71x0v0b1 0 UZA1%0#U Thawte Consulting (Pty) Ltd.1,0*U#Thawte Personal Freemail Issuing CAS| 6$1-~j0 *H 1xv0b1 0 UZA1%0#U Thawte Consulting (Pty) Ltd.1,0*U#Thawte Personal Freemail Issuing CAS| 6$1-~j0 *H "%1>rCPM 8|ڸo(E_KuhNԺq.sqǟ88wL~JC Цe&TBuÊNn&{X%`6#)($c )8(< @WIa(83E^QX]r?dV.+V4?yl _N)%lpʵo('z 4=yxe騤wWJ u
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