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- Newsgroups: comp.os.vms
- Path: sparky!uunet!cs.utexas.edu!convex!constellation!geohub.gcn.uoknor.edu!dwight
- From: dwight@geohub.gcn.uoknor.edu (Dwight D. Moore)
- Subject: Re: Problems with EXABYTE tape drive
- Originator: news@kittyhawk.ecn.uoknor.edu
- Sender: usenet@constellation.ecn.uoknor.edu (Usenet Administrator)
- Message-ID: <C1Ez2q.DA4@constellation.ecn.uoknor.edu>
- Date: Mon, 25 Jan 1993 14:32:49 GMT
- Reply-To: dwight@geohub.gcn.uoknor.edu
- References: <1993Jan22.200938.22220@das.harvard.edu>
- Nntp-Posting-Host: kittyhawk.ecn.uoknor.edu
- Organization: Geosciences Computing Network, Univ. of Oklahoma
- Keywords: EXABYTE
- Lines: 41
-
- In article <1993Jan22.200938.22220@das.harvard.edu>, chen@speed.uucp (Lilei Chen) writes:
- |>Path: constellation!mimbres.cs.unm.edu!ogicse!das-news.harvard.edu!speed!chen
- |>From: chen@speed.uucp (Lilei Chen)
- |>Newsgroups: comp.os.vms
- |>Subject: Problems with EXABYTE tape drive
- |>Keywords: EXABYTE
- |>Message-ID: <1993Jan22.200938.22220@das.harvard.edu>
- |>Date: 22 Jan 93 20:09:38 GMT
- |>Article-I.D.: das.1993Jan22.200938.22220
- |>Sender: usenet@das.harvard.edu (Network News)
- |>Organization: Aiken Computation Lab, Harvard University
- |>Lines: 11
- |>
- |>On our site we use EXABYTE tape drive for backup purpose. But we
- |>can not get more than 500MB on a 112M tape which is supposed to be
- |>able to hold more than 2GB according to the specification. We have
- |>about five drives and all behave the same way. We even tried it on
- |>a PC with an ADAPTEC SCSI controler, but the result is the same.
- |>EXABYTE claimed that they don't know anything about the possible
- |>cause. So I am asking the net if anyone has encountered similar
- |>problems with EXABYTE tape drive and/or knows its possible cause.
- |>Thanks.
- |>
- |>Jim (xue@cfaft5.harvard.edu)
- |>
- Exabyte 8200 write in 512 byte blocks. If you write small records
- < 512, then space is wasted (or block size that aren't multiples
- of 512 also). The 8200 isn't smart enough to pack the
- blocks on tape. This will cause a less that optimal tape usage.
- The 8500 writes in 1024 byte blocks, but can also fill unused
- portions of the block, so is an improvment from the 8200 drive.
- Also, the inter-record gap is rather large, so the bigger the
- output records, the better tape usage you get...
- ----------------------------------------------------------------------------
- Dwight D. Moore
- Geosciences Computing Network
- University of Oklahoma
-
- dwight@geohub.gcn.uoknor.edu (129.15.40.10)
- These opinions do not necessarily represent the opinions of OU or the GCN.
- ----------------------------------------------------------------------------
-