Woohoo! Somebody who knows how to reply to a thread! <grin> > -----Original Message----- > From: Rainer Mager [mailto:[EMAIL PROTECTED]] > Sent: Tuesday, February 01, 2000 7:58 AM > To: Linux-RAID > Subject: RE: Argh, more problems with SCSI and RAID > > > Multiple responses to responses in 1 message, I hope no one > gets confused... > > > First off, I did some testing with normal SCSI (no RAID) > (yes, I do know > this is a RAID mailing list, but everyone is being so helpful > I hope I'm > forgiven ;-). I wrote simultaneously to each of my 4 SCSI > drives as fast as > I could (via cat /dev/zero > drive/file). Doing this > produced no errors > and I stopped it after about 15 minutes (approx 500MB per disk). I did > receive this during the operation, though: > > Feb 1 22:48:13 dual kernel: (scsi1:0:0:0) Performing Domain > validation. > Feb 1 22:48:13 dual kernel: (scsi1:0:0:0) Successfully > completed Domain > validation. No idea what domain it's referring to. > Feb 1 22:48:18 dual named[968]: Cleaned cache of 0 RRs > Feb 1 22:48:18 dual named[968]: USAGE 949412898 949358898 > CPU=0.12u/0.1s > CHILDCPU=0u/0s > Feb 1 22:48:18 dual named[968]: NSTATS 949412898 949358898 > A=7 MX=2 ANY=3 > Feb 1 22:48:18 dual named[968]: XSTATS 949412898 949358898 > RR=18 RNXD=1 > RFwdR=13 RDupR=0 RFail=0 RFErr=0 RErr=0 RAXFR=0 RLame=0 > ROpts=0 SSysQ=4 > SAns=3 SFwdQ=6 > SDupQ=13 SErr=0 RQ=12 RIQ=0 RFwdQ=0 RDupQ=4 RTCP=0 SFwdR=13 > SFail=0 SFErr=0 > SNaAns=3 SNXD=0 Looks like named messages, the first is it clearing cache (does that about every 24 hours). The others I'm not sure about, but they're all from named, so not all all RAID related. > > > Is this normal? Should it just periodically appear? The first part of the named stuff, yes, not sure about the rest. > > Before when I got all my timeouts is when I was doing 2 > things I haven't > tried again yet. One, I had all my SCSI drives being used a > swap. Two, I was > trying to back up to my SCSI tape drive. I'll try these again > later when I'm > ready for another crash ;-( As it is right now, everything > seems stable, > albeit a bit slow. Do you have any swap on those drives now? > Now follows some responses to responses.... > > > -----Original Message----- > From: Stephen Waters [mailto:[EMAIL PROTECTED]] > > or you could just configure the transfer rate to be one > notch lower than > > your current level. had to do that with my 4 U2W drives in > a hotswap box > > w/ a tekram dc390u2b (symbios chipset). > > True but I did some benchmarking today using both "hdparm > -tT" and another > simple test and I'm finding terrible throughput. My one drive > that is on a > dedicated bus and should be able to do up to 40MB/s is only > getting about 9 > MB/s. An older SCSI drive (on a different bus) that should be > able to do 5MB > is only getting 2MB. This is making me think something else is wrong. > > I may try your suggestion anyway and see if reducing the > speed helps at all. > Interestingly, the Linux says the 40MB/s drive is running at > 32MB/s. Either > way it is far more than the measured 9 MB/s. 40MB/sec is the BUS speed, NOT the drive speed. I doubt that many drives can supply 40MB/sec at this point, and I'm pretty sure that no single drive can supply data fast enough to saturate 80MB/sec or 160MB/sec SCSI. What are the specs on the drive that's doing 9MB/sec? The one that's only getting 2? > > From: Peter Pregler [mailto:[EMAIL PROTECTED]] > > I had similar problems (actually your messages could be a > cut-and-paste of > > my old logs) with my box at the beginning. The actual > problems was that > > the scsi-bus did not fullfill the specifications. Replacing > some hardware > > (hot-swap boxes) solved it. BTW, all worked well under DOS in the > > test-environment shipped. But as soon as linux got on the > box and did > > _really_ use the bandwidth on the bus the troubles showed > up (timeouts, > > renegotiation, slowdown ...). > > Hmm, good info here. But I don't know how it helps. I know > and acknowledge > that some of my drives are old/slow but shouldn't they still > work without > errors? When you say you replaced "hot-swap boxes" you are > talking about > drives, not SCSI cards, right? Talking about some "boxes" that take up a couple of 5.25 inch drive bays, and probably have either chassis for the drives, or SCA drives, so that you can hot-swap drives and not risk drive/controller damage. Of course, you should probably only be removing the drives if they're dead... > BIOS. I had a > > similar problem this last weekend with 2.2.14 and 5.1.21 > AIC-7xxx and > async Is this a patch to 2.2.14? Where from? > > Oh-ho. That's an interesting discovery. I'm, of course, > hesitant to redurce > my throughput, especially since it is so low to start out > with (see above) > but that is better than timeouts, etc. I'll give it a shot. See above on "low" throughputs. Greg
