From - Tue Nov 12 16:36:52 1996 Newsgroups: comp.sys.sgi.admin Path: news.unizar.es!news.rediris.es!news.uoregon.edu!newsfeed.internetmci.com!in1.uu.net!news2.new-york.net!halo.angel.net!nina From: NBP Subject: 4mm dat tapes Content-Type: TEXT/PLAIN; charset=US-ASCII X-Nntp-Posting-User: (Unauthenticated) Message-ID: Mime-Version: 1.0 X-Sender: nina@halo.angel.net X-Trace: 847318627/4613 X-Nntp-Posting-Host: halo.angel.net Date: Wed, 6 Nov 1996 22:17:59 GMT Lines: 15 When I go into the System Manager showing my 4 mm dat drive, it shows the capacity to be just 1253MB. Is there a way to change the capacity of the drive? N ===================================================================== Nina Burns Pomeroy Senior Consultant/Designer Kinetic Wave nina@kineticwave.com www.kineticwave.com ===================================================================== From - Tue Nov 12 16:36:52 1996 Path: news.unizar.es!news.rediris.es!news.belnet.be!swsbe6.switch.ch!swidir.switch.ch!surfnet.nl!howland.erols.net!newspump.sol.net!www.nntp.primenet.com!nntp.primenet.com!enews.sgi.com!news.sgi.com!gazette.engr.sgi.com!anchor.engr.sgi.com!olson From: olson@anchor.engr.sgi.com (Dave Olson) Newsgroups: comp.sys.sgi.admin Subject: Re: 4mm dat tapes Date: 7 Nov 1996 08:22:23 GMT Organization: Silicon Graphics Inc., Mountain View, CA Lines: 17 Message-ID: <55s67v$1fo@gazette.engr.sgi.com> References: NNTP-Posting-Host: anchor.engr.sgi.com X-Newsreader: NN version 6.5.0 #2 (NOV) NBP writes: | When I go into the System Manager showing my 4 mm dat drive, it shows | the capacity to be just 1253MB. Is there a way to change the capacity of | the drive? That number would be right for 60m tapes. 90m is 2GB (native). If you have a DDS2 drive, it's 4GB on 120m tapes, perhaps as much as double that with compression enabled. The system manager tool might have the 60m capacity hardcoded into it, if it's an older release; just ignore that. -- Dave Olson, Silicon Graphics Guru and busybody at large http://reality.sgi.com/olson olson@sgi.com From - Tue Nov 12 16:36:52 1996 Path: news.unizar.es!news.rediris.es!news.uoregon.edu!arclight.uoregon.edu!dispatch.news.demon.net!demon!www.nntp.primenet.com!nntp.primenet.com!swrinde!elroy.jpl.nasa.gov!lll-winken.llnl.gov!fnnews.fnal.gov!unixhub!news.Stanford.EDU!ulysses!tkunze From: tkunze@ulysses. (Tobias Kunze) Newsgroups: comp.sys.sgi.admin Subject: Re: 4mm dat tapes Date: 9 Nov 1996 19:17:44 GMT Organization: Silicon Graphics, Inc. Mountain View, CA Lines: 26 Message-ID: <562lco$n1i@nntp.Stanford.EDU> References: <55s67v$1fo@gazette.engr.sgi.com> NNTP-Posting-Host: ulysses.stanford.edu > That number would be right for 60m tapes. 90m is 2GB (native). > If you have a DDS2 drive, it's 4GB on 120m tapes, perhaps as much > as double that with compression enabled. How do I enable compression? The jumper on the tape (ARCHIVE: Python 01931-XXX5.63) is set to enable compression, but still i get only 4GB on a DDS2 120m tape. man mt doesn't do it either. Obviously, I have no clue about tapes, Im afraid. Another question is: how do I incremental backups on the DAT? Using tar rv, it takes *forever* until it finds the end of the archive already on tape, even if I mt to the end of the data before ("forever" meaning about an hour or more). When it finally finds the end, it just complains there wouldn't be enough space on tape, even though I know there is a gig left... I assume there must be a way of writing to and reading from multiple tape archives on one tape quickly and simple... ______________________________________________________________________ Tobias Kunze t@kunze.stanford.edu CCRMA, Stanford University http://www.stanford.edu/~tkunze From - Tue Nov 12 16:36:52 1996 Path: news.unizar.es!news.rediris.es!news.belnet.be!swsbe6.switch.ch!swidir.switch.ch!01-newsfeed.univie.ac.at!voskovec.radio.cz!btnet-feed2!btnet!dispatch.news.demon.net!demon!www.nntp.primenet.com!nntp.primenet.com!news.sgi.com!gazette.engr.sgi.com!anchor.engr.sgi.com!olson From: olson@anchor.engr.sgi.com (Dave Olson) Newsgroups: comp.sys.sgi.admin Subject: Re: 4mm dat tapes Date: 10 Nov 1996 19:10:39 GMT Organization: Silicon Graphics Inc., Mountain View, CA Lines: 39 Message-ID: <5659bf$ab@gazette.engr.sgi.com> References: <55s67v$1fo@gazette.engr.sgi.com> <562lco$n1i@nntp.Stanford.EDU> NNTP-Posting-Host: anchor.engr.sgi.com X-Newsreader: NN version 6.5.0 #2 (NOV) tkunze@ulysses. (Tobias Kunze) writes: | > That number would be right for 60m tapes. 90m is 2GB (native). | > If you have a DDS2 drive, it's 4GB on 120m tapes, perhaps as much | > as double that with compression enabled. | | How do I enable compression? The jumper on the tape (ARCHIVE: | Python 01931-XXX5.63) is set to enable compression, but still i get only | 4GB on a DDS2 120m tape. man mt doesn't do it either. Obviously, | I have no clue about tapes, Im afraid. Setting the jumper sets the default, for OS's that don't do it in software. It definitely works (you have to powercycle, of course). With 6.2, where we do it in software, the jumper shouldn't have any effect; you need to use the 'c' device if you want compression. See 'man 7 intro'. | Another question is: how do I incremental backups on the DAT? Using | tar rv, it takes *forever* until it finds the end of the archive already | on tape, even if I mt to the end of the data before ("forever" meaning | about an hour or more). When it finally finds the end, it just complains | there wouldn't be enough space on tape, even though I know there is a | gig left... An hour is about right, if the tape is nearly full. If you are using fixed block, it may be slower also. The fastest way is to not use the 'r' option, and simply write a new tape file at the end, although that's not as seamless, of course. | I assume there must be a way of writing to and reading from multiple | tape archives on one tape quickly and simple... By definition, tar r is only one archive. -- Dave Olson, Silicon Graphics Guru and busybody at large http://reality.sgi.com/olson olson@sgi.com From - Tue Nov 12 16:36:52 1996 Path: news.unizar.es!news.rediris.es!news.belnet.be!swsbe6.switch.ch!swidir.switch.ch!in2p3.fr!univ-lyon1.fr!pasteur.fr!jussieu.fr!math.ohio-state.edu!howland.erols.net!feed1.news.erols.com!uunet!in3.uu.net!diamond.waii.com!news From: Pete Forman Newsgroups: comp.sys.sgi.admin Subject: Re: 4mm dat tapes Date: 07 Nov 1996 10:12:42 +0000 Organization: Western Geophysical, Div. of Western Atlas Int'l, Bedford, UK Lines: 17 Message-ID: References: NNTP-Posting-Host: nemo.bedford.waii.com X-Newsreader: Gnus v5.2.25/XEmacs 19.14 >>>>> "NBP" == NBP writes: NBP> When I go into the System Manager showing my 4 mm dat drive, NBP> it shows the capacity to be just 1253MB. Is there a way to NBP> change the capacity of the drive? That is the capacity for a 60m tape. I have had no problem writing 2G to a 90m tape. Can anyone tell me what should happen with a 120m tape. I realise that I would not get the 4G capacity of DDS-2 with my hardware (ARCHIVE: Python 25601-XXX2.75) but might I still get 2.6G? -- Pete Forman Western Geophysical pete.forman@bedford.waii.com From - Tue Nov 12 16:36:53 1996 Path: news.unizar.es!news.rediris.es!news.belnet.be!swsbe6.switch.ch!swidir.switch.ch!news.grnet.gr!btnet-feed2!btnet!dispatch.news.demon.net!demon!www.nntp.primenet.com!nntp.primenet.com!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!su-news-hub1.bbnplanet.com!su-news-feed4.bbnplanet.com!enews.sgi.com!news.corp.sgi.com!inn From: Alexis Cousein Newsgroups: comp.sys.sgi.admin Subject: Re: 4mm dat tapes Date: Fri, 08 Nov 1996 18:28:45 +0100 Organization: Silicon Graphics Belgium Lines: 23 Message-ID: <32836DCD.7DE1@brussels.sgi.com> References: NNTP-Posting-Host: lancelot.brussels.sgi.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 2.02S (X11; I; IRIX 5.3 IP22) To: Pete Forman Pete Forman wrote: > > >>>>> "NBP" == NBP writes: > > NBP> When I go into the System Manager showing my 4 mm dat drive, > NBP> it shows the capacity to be just 1253MB. Is there a way to > NBP> change the capacity of the drive? > > That is the capacity for a 60m tape. I have had no problem writing > 2G to a 90m tape. > > Can anyone tell me what should happen with a 120m tape. I realise > that I would not get the 4G capacity of DDS-2 with my hardware > (ARCHIVE: Python 25601-XXX2.75) but might I still get 2.6G? > No. You'll get unreliable media, as a DDS-1 drive can't correctly tension 120m tapes. Just don't do it if you value your backups. -- Alexis Cousein Sales Support Engineer Silicon Graphics NV/SA (Belgium) in .be domain: al@sgi.be, elsewhere: al@brussels.sgi.com