Date: Sat, 22 Apr 1995 10:58:16 -0700 (PDT) From: "Rodney W. Grimes" <rgrimes@gndrsh.aac.dev.com> To: jgreco@brasil.moneng.mei.com (Joe Greco) Cc: freebsd-hackers@FreeBSD.org Subject: Re: large filesystems/multiple disks [RAID] Message-ID: <199504221758.KAA02014@gndrsh.aac.dev.com> In-Reply-To: <9504221549.AA14262@brasil.moneng.mei.com> from "Joe Greco" at Apr 22, 95 10:49:42 am
next in thread | previous in thread | raw e-mail | index | archive | help
> > > Any one want to buy my Quantum Empire 2100 for $800, it's less than 120 days > > old, as I am now going to sell it off and go buy 4 very fast 500MB > > drive and make a stripe driver out of this code :-). > > > > [....] > > > > I have read the code in stripe.tar, it should be a day or twos work > > to get it up and running under FreeBSD. > > Hi Rod, > > Did you ever make any progress on this? If not, I will (try to) look at > it, but I'd prefer that somebody that knows what the heck they're doing down > within the device driver code putz with it.. :-) Yes, I played with that code (infact I have a kernel with /dev/ilv in it). I never made it work completly. Then I remeber the sys/dev/cd.c driver that came with 4.4 Lite and went and looked at it. I also have that working (renamed to concat.c to elimanate the conflict) partially, enough to say that I took 2 4MB/sec drives and interleaved them and got a 5.2MB/sec transfer rate for reads (I can't write due to bugs) *with out* spindle sync. I have done a bunch of aggregate bandwidth testing now using from 1 to 4 NCR810 SCSI controllers on a P54C-90 and found I can actually hit 12-14MB/sec using 4MB/sec drives. We seem to have a bottleneck in the ncr.c driver when trying to run multiple drives on one controller. I have run single drives on that controler at 6.6MB/sec, but two 4MB drives only get 5.3MB/sec. My first pass through concat.c was a ``mechanical conversion, just make the bloody thing compile and do *something*''. I am now onto the task of actually going through it and cleaning it up to work correctly. I have also been working with Peter Default on some scsi(8) commands to try and get my DEC 3053L drives to go into spindle sync mode. They are all wired up for it, but you have to set one drive to be the sync master via a mode select ioctl and we are having troubles getting this to work :-(. > Having recently seen Solaris' Online: DiskSuite, which suffers from fairly > significant performance degradations, I'm curious to see what a real > operating system can do. ;-) It will be at least another week, but you'll now I have made serious progress when you see a cvs commit message for the import of sys/dev/concat. -- Rod Grimes rgrimes@gndrsh.aac.dev.com Accurate Automation Company Custom computers for FreeBSD
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199504221758.KAA02014>