Date: Mon, 13 Sep 2004 11:24:19 +0200 From: Frode Nordahl <frode@nordahl.net> To: =?ISO-8859-1?Q?S=F8ren_Schmidt?= <sos@DeepCore.dk> Cc: current@freebsd.org Subject: Re: Promise PDC20267 ATA RAID, poor write performance Message-ID: <B09A569C-0566-11D9-AA63-000A95A9A574@nordahl.net> In-Reply-To: <4142D833.4060802@DeepCore.dk> References: <EC95929E-031F-11D9-AA63-000A95A9A574@nordahl.net> <4142D833.4060802@DeepCore.dk>
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On Sep 11, 2004, at 12:49, S=F8ren Schmidt wrote: > OK I got this this setup now: > > atapci0: <Promise PDC20267 UDMA100 controller> port=20 > 0xb000-0xb03f,0xb400-0xb403,0xb800-0xb807,0xd000-0xd003,0xd400-0xd407=20= > mem 0xfd000000-0xfd01ffff irq 16 at device 3.0 on pci0 > ad1: 14305MB <Maxtor 2R015H1/EAH41MF0> [29065/16/63] at ata2-master=20 > UDMA100 > ad2: 14305MB <Maxtor 2R015H1/EAH41MF0> [29065/16/63] at ata3-master=20 > UDMA100 > ar0: 14305MB <ATA RAID1 array> [1823/255/63] status: READY subdisks: > > Controller the same, disks are an earlier verision of those "low=20 > profile" Maxtor disks, just somewhat slover than yours. > > pizzabox# dd if=3D/dev/zero of=3Dfill bs=3D1m count=3D2000 > 2000+0 records in > 2000+0 records out > 2097152000 bytes transferred in 122.908771 secs (17062672 bytes/sec) I have done some more test now, reseated cables, disabling other IDE=20 controllers etc. to no avail. I have tested both drives against the=20 ICH2 controller with very good results. After some fooling around I found the following: ar0: ATA RAID1 subdisks: ad4 ad6 status: READY # dd if=3D/dev/zero of=3Dfill bs=3D1m count=3D100 100+0 records in 100+0 records out 104857600 bytes transferred in 29.298259 secs (3578970 bytes/sec) # atacontrol detach ata2 # dd if=3D/dev/zero of=3Dfill bs=3D1m count=3D100 100+0 records in 100+0 records out 104857600 bytes transferred in 3.080246 secs (34041957 bytes/sec) (this also works when writing 2GB...) That is, whenever I run with a single disk or a degraded RAID transfer=20= speeds are ok. I have tried this both ways, so it is not one of the=20 disks / cables that is broken. As soon as I rebuild the RAID again,=20 write speeds drop to 3MB/s. Any ideas as of how to debug this? Mvh, Frode > -S=F8ren >
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