Subject: Re: ahc and raidframe questions
To: Greg Oster <>
From: Chris Jones <>
List: netbsd-users
Date: 06/23/1999 15:05:11
>>>>> "Greg" == Greg Oster <> writes:

>> * Doing anything with the RAID array seems pretty slow.  It took
>> over two hours to initialize the parity information for a RAID5
>> array across three 9G disks.  It's currently doing a 17GB newfs,
>> and it looks like that will take about an hour by the time it's
>> done.

Greg> Given that it's got to read 18 GB of data and write 9GB of data,
Greg> it's going to take a little while to re-write parity, even with
Greg> fast disks...  I'm not sure if 2 hours is unreasonable or not,
Greg> as I've never worked with a RAID set that big with RAIDframe,
Greg> nor have I used UW controllers/drives (yet). (I've thought about
Greg> how nice it would be, but that's it :) )

Yeah, it's a good point.  But once the filesystem is there, it writes
files at about 1.7 MB/s.  This seems really slow to me.  Of course, I
might just have over-inflated expectations, but UW SCSI is supposed to
be fast.

Greg> [snip]
>> This is an i386, 1.4 system.

Greg> What CPU?

It's a Pentium 120MHz.  RAIDFrame isn't *that* CPU intensive, is it?
I'll check in a few minutes here, I guess.  I can run top while doing
stuff to it.

Greg> It could also be that the stripe width (or sectors per stripe
Greg> unit) are not optimal for those drives/your machine.

Yeah.  I was trying to avoid experimenting with it, but I guess that's
what I'm going to do now.  I'll use small partitions, I think.  :)


Chris Jones                                
           Mad scientist at large          
"Is this going to be a stand-up programming session, sir, or another bug hunt?"