Path: utzoo!utgpu!cunews!bnrgate!brtph3!brchh104!brchs1!bnr.ca!rice.edu!sun-spots-request
From: pln@egret1.stanford.edu (Patrick L. Nolan)
Newsgroups: comp.sys.sun
Subject: Big disks not hazardous to your data.
Keywords: Hardware
Message-ID: <2269@brchh104.bnr.ca>
Date: 2 Apr 91 15:00:00 GMT
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Organization: Sun-Spots
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Approved: Sun-Spots@rice.edu
X-Original-Date: 29 Mar 91 21:39:59 GMT
X-Sun-Spots-Digest: Volume 10, Issue 71, message 11
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A couple of weeks ago I posted a quote from an article in Digital News.
This article said that the DEC SCSI drivers are faulty in both VMS and
Ultrix, to the extent that data may be destroyed on disks larger than 1
GByte.  It suggested that this is a generic problem due to using SCSI
Group 0 commands, and that it might affect computers by other
manufacturers.

The replies I received have been unanimous on two points:

1. Sun also uses SCSI Group 0, which means that no more than 2**21 blocks
   (1 GByte) can be accessed on a disk.

2. Data will not be harmed because something in SunOS (format?  newfs?)
   will not let you format a SCSI disk with more than 1 GB.  This is where
   DEC falls down.

This means that so-called 1.2 GB drives like the Fujitsu M2266SA lose
about 0.8% of their useful capacity, which is certainly acceptable.
However, the new 1.6 and 2.0 GB drives will act like very expensive 1GB
models.

There are hints/rumors that Sun has something in the works that will use
Group 1 commands.

*   Patrick L. Nolan            (415)723-0133                 *
*   W. W. Hansen Experimental Physics Laboratory (HEPL)       * 
*   Stanford University                                       *
*   Bitnet: PLN@SLACVM    Internet: pln@egret1.stanford.edu   *