Date: Fri, 8 May 1998 18:41:08 +0200 (MET DST) From: Wilko Bulte <wilko@yedi.iaf.nl> To: tlambert@primenet.com (Terry Lambert) Cc: kpielorz@caladan.tdx.co.uk, tlambert@primenet.com, tom@sdf.com, beng@lcs.mit.edu, dec@phoenix.its.rpi.edu, freebsd-hackers@FreeBSD.ORG Subject: Re: dump/restore problem (was: Network problem with 2.2.6-RELEASE) Message-ID: <199805081641.SAA12479@yedi.iaf.nl> In-Reply-To: <199805072234.PAA14231@usr01.primenet.com> from Terry Lambert at "May 7, 98 10:34:27 pm"
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As Terry Lambert wrote... > > Hoping this helps rule out something... > > > > I have 11.5Gb's of EIDE 'storage' (2 x 4.5Gb EIDE's, and 1 x 2.5Gb EIDE) > > all running off a 440FX chipset controller, and I can back them up and > > restore them with no problems at all. I'm running the driver in DMA mode - > > but I've also had it running in standard PIO mode as well (i.e. flags > > 0x0). I have the same SCSI controller as Tom, i.e. a 2940UW. > > > > The only other thing I can think of is that DLT is a damned site faster > > than DAT - my DAT drive manages about 600k/sec to/from tape, I beleive a > > DLT is going to run at anything from 1-4Mb/sec, which is going to 'stress' > > the SCSI / IDE side an awful lot more (and working under the principal one > > of the best ways to break a system is to 'stress' it) maybe were seeing > > something like that here? > > The DLT may do something strange, like write blank blocks in order to > keep streaming. A lot of drives tend to do that. The fix, if this Nope, it starts 'shoe shining'. The DLT7000 might drop out of compressed mode in an attempt to keep streaming. DLT[24]000 don't do this AFAIK. > were the case, would be to download "team" or "ddd", either of which use > multiple processes with interleaved I/O and token passing to make > the data really fly off the machine. DLTs need blocksizes >= 64 Kb to be kept happy streaming. I used a DLT2000 for years on my FreeBSD box, I now have a DLT4000. I can't keep 'm streaming from a 4G Barracuda with the current 64kB physio() limit. Keep the tape and the disks on seperate SCSI channels (I have 2x NCR810). I've never even *owned* a IDE disk, let alone used one on my system so I cannot comment on what this might do with DLT drives. Wilko _ ______________________________________________________________________ | / o / / _ Bulte email: wilko @ yedi.iaf.nl |/|/ / / /( (_) Arnhem, The Netherlands WWW: http://www.tcja.nl ______________________________________________ Powered by FreeBSD __________ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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