On Wed, Aug 20, 2003 at 11:21:49AM -0400, Eric Sproul wrote:
> Hi all,
> I am having a problem with disk I/O on a new holdingdisk I installed in
> my AMANDA server. The server had previously been exclusively SCSI, and
> I had no problems. When we broke down an old server, I snagged a 60GB
> IDE drive (an IBM Deskstar 75GXP) to use as cheap extra holding disk
> space-- "free" as opposed to ~$450 for a similar-sized SCSI drive. The
> problem is, the read throughput is terrible and it's causing backups to
> run about twice as long, due to taper not being able to extract stuff
> off the holding disk fast enough.
>
> The AMANDA server is PC-based, with Tyan Thunder 100 (S1836) mobo and
> the i440GX chipset (PIIX4 integrated IDE controller). According to the
> manual, the IDE controller should do up to ATA/33 (UDMA mode 2, I
> believe). It's running Debian testing/unstable, with kernel 2.4.21.
>
> Anyway, I plug the drive up, setting the BIOS to auto-everything for IDE
> disks. I see the disk come up and get recognized. However, when the
> kernel detects the IDE disk, it reports no UDMA setting, leading me to
> believe it came up in one of the older PIO modes. This is confirmed
> with a quick hdparm test that shows an abysmal 4.5 MB/s buffered disk
> read speed. By comparison, the same disk at UDMA(33) in a similar
> machine reports 28 MB/s.
>
> Does anyone here have experience with IDE and DMA under recent Linux
> kernels? Anyone else have a problem like this? I figured the
> integrated controller on a 440GX board would have no compatibility
> problems, as it's extremely common. Maybe I'm wrong.
Not linux, but Solaris. I'm also on a 440 board, but I think BX.
I have two SCSI disks and a chunk of each used for holding disk.
I also have a larger IDE disk and used to use a chunk of that for
holding disk too. But it proved too low performing so I dropped it
except for storage of static data.
--
Jon H. LaBadie jon AT jgcomp DOT com
JG Computing
4455 Province Line Road (609) 252-0159
Princeton, NJ 08540-4322 (609) 683-7220 (fax)
|