Subject: Re: Disk performance under NetBSD on A3000
To: None <amiga@NetBSD.ORG>
From: Michael L. Hitch <>
List: amiga
Date: 04/25/1995 09:11:02
On Apr 25, 12:22am, Stephen Champion wrote:
> 	Sysinfo reports 1.2M/s on the LPS and 3.5M/s on the EMP.  I 
> haven't done any raw tests under NetBSD (won't writing to /dev/sd1c 
> destroy the filesystem??).

  Yes, writing to /dev/sd1c (actually /devrsd1c if you really want raw
writes) will destroy the filesystem - and the RDB blocks as well.  If
you want to test raw writes, you will need an empty partition and MAKE
SURE you specify that partition, not the raw partition /dev/rsd?c.

  If you just want to compare Sysinfo speeds to NetBSD, then you can easily
do the raw reads from the disk [which is all I think SysInfo does].

> 	As I understand it, rotdel influences where on the disk data is written.
> So, data written when the rotdel was 4 will not gain from the change.  Is 

  That's correct.

> there anything in out there (or in the standard distribution) that will 
> realign the data already on the drive to benefit from the change, or do I 
> need to back up, mkfs, and restore the file systems to affect the data 
> already there?  I didn't see anythoing to this effect in the fsck or 
> tunefs man pages, or their references.

  Backup and restore is the only way I know to restructure the file system.


Michael L. Hitch			INTERNET:
Computer Consultant
Office of Systems and Computing Services
Montana State University	Bozeman, MT	USA