Date: Sat, 25 May 1996 20:41:32 +0200 (MET DST) From: Wilko Bulte <wilko@yedi.iaf.nl> To: andreas@knobel.gun.de (Andreas Klemm) Cc: joerg_wunsch@uriah.heep.sax.de, freebsd-scsi@FreeBSD.org Subject: Re: dump and 32blocks limit Message-ID: <199605251841.UAA03599@yedi.iaf.nl> In-Reply-To: <Pine.BSF.3.92.960525105145.594A-100000@knobel.gun.de> from "Andreas Klemm" at May 25, 96 10:57:17 am
next in thread | previous in thread | raw e-mail | index | archive | help
> On Fri, 24 May 1996, Wilko Bulte wrote: > > > > As Wilko Bulte wrote: > > > > > > > I'm not absolutely sure this is SCSI-only related but: > > > > > > > > I grabbed the -current dump sources and found a 32 block limit builtin > > > > there. Comment sez: restore can't read >32, maybe a bug in the tapedriver. > > > > > > > > I was aware of 64kbyte rawio limit, but this 32 is new to me. I ran > > > > dumps with 128 (== 64kbyte) and never had restore nuke me. > > > > > > The claim with the 32 KB blocking was Andreas Klemm's one. > > > > Andreas, > > Any more info on this?? > > Well, sometimes I had a SUN 4mm DAT (Archive Python) at home. > When doing backups with dump everything seemed to be fine. I could > choose blocksizes of about 96 blocks (as it's usual on Sun's). > > But when I tried to read those tapes with restore, I got an error > message (forgot which exactly), you could perhaps browse the -current > list for my e-mail... The result was, that I was only able to restore > dumps that were made with a blocksize <= 64 blocks if I remember > exactly. Hmmmmmmmmmm.... The thing is I _never_ saw it on my tape units (I have a couple, you probably saw the list on -scsi go by). So, I'm wondering if it is really a sw bug or it is a device-specific FreeBSD interaction. I've seen far too much strange errors coming from crappy firmware in devices. > Untli this bug is fixed somewhere in kernel land I had the idea to > disallow blocksizes >64 blocks in dump ... I think people wouldn't find > it funny, if they are unable to restore their backups in case they > saved the time of verifying a dump ;-)) I agree a readable dump is strongly preferable :^) This gets back to my question posted sometime ago: how does one verify a dump??? That is, without actually restoring it.. Correct me if I'm wrong but I did not see any options to do this. (Of course you need a _really_ quiescent filesystem to make this work) If a more or less painless 'compare' is feasible, I can try to do some testing with the various tapehardware. I can borrow I think some 10 types of different tape units from my boss (QIC, Exabyte, DAT, DLT). > Don't ask me, what's exactly the reason for this ... Was this broken > in 1.1.5.1, too ??? I don't know... > > Andreas /// Wilko _ __________________________________________________________________________ | / o / / _ Wilko Bulte email: wilko@yedi.iaf.nl |/|/ / / /( (_) Private FreeBSD site - Arnhem - The Netherlands --------------------------------------------------------------------------------
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199605251841.UAA03599>