[rescue] hard drives for sparc10?

[Peter Corlett]

Joshua Boyd  <jdboyd at jdboyd.net> wrote:
> On Tue, Jan 18, 2005 at 10:55:33AM +0000, Peter Corlett wrote:
[...]
>> Surprisingly, the drive's more reliable on the SCSI bus than when
>> it was on IDE, despite me not using goats and black candles.
> Err, isn't that a relatively old (more than a year? Two years?)
> drive though?

I have a faint memory that it was bought in April 2003. However why
would more recent drives suddenly become more incompatible? I'd expect
them to migrate closer to the SCSI spec if anything.

[...]
> I've heard that if you can ever find a serial scsi card, you can
> directly connect SATA disks. Meaning, that SATA is officially a
> proper subset of SCSI rather than something else that got SCSIfied
> over the years.

That's interesting if true, but I'd want to see a reference before I
believe it.

> I've also heard that SATA is very, very fast. What I've been hearing
> suggests that a single drive will certainly be fast enough for
> uncompressed video, and might even be fast enough for dual stream
> uncompressed editing, depending on specifics of the drive and the
> video formats used.

On one of our Linux boxes, it has a pair of SATA drives that we have
software RAID-1 on:

# cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
  Vendor: ATA      Model: Maxtor 6B200M0   Rev: BANC
  Type:   Direct-Access                    ANSI SCSI revision: 05
Host: scsi0 Channel: 00 Id: 01 Lun: 00
  Vendor: ATA      Model: Maxtor 6B200M0   Rev: BANC
  Type:   Direct-Access                    ANSI SCSI revision: 05

(Note that just because it's /dev/sd* doesn't mean it's SCSI, but
merely that it was more convenient to the driver writer to make it
look like SCSI rather than IDE. USB mass-storage devices are similar.)

As to the raw read performance of the raw disk and RAID device:

# hdparm -Tt /dev/{sda,md0}

/dev/sda:
 Timing cached reads:   3832 MB in  2.00 seconds = 1916.00 MB/sec
 Timing buffered disk reads:  184 MB in  3.01 seconds =  61.13 MB/sec

/dev/md0:
 Timing cached reads:   3880 MB in  2.00 seconds = 1940.00 MB/sec
 Timing buffered disk reads:  178 MB in  3.00 seconds =  59.33 MB/sec

-- 
It used to be a good hotel, but that proves nothing - I used to be a good boy.
								- Mark Twain