Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cmcl2!rna!dan
From: dan@rna.UUCP (Dan Ts'o)
Newsgroups: comp.periphs
Subject: WORMs acting like R/W disks...
Message-ID: <680@rna.UUCP>
Date: 28 Jun 89 01:04:11 GMT
Organization: Rockefeller University - Neurobiology
Lines: 26


	I just heard about a new device called the OCU-100 (Optical Conversion
Unit) from TenX Technology in Austin. It is a SCSI device that sits between
the host/SCSI bus and a WORM drive and makes the WORM emulate a read/write
disk. It seems pretty well thought out and apparently works with any SCSI host
and OS, including MVAX's, Sun's and PC's running UNIX.
	Its success is of course application dependent, but given a good match
(lots of static data, a few changes), you can pretend that it is a read/write
disk and need no special device drivers. You can pretend that the entire
optical capacity is available as read/write because it does data compression
and the extra capacity generated usually covers the extra sectors required for
the small changes (in an archival application). A cute feature is that you
can backtrack in time and examine the (UNIX) filesystem state at any time in
the past. It also looks like a 512byte sector device, even if the WORM is a
1K or 2K device.

	So it sounded good to me. Does anyone have any experience or further
knowledge or opinions about it ?

				Cheers,
				Dan Ts'o		212-570-7671
				Dept. Neurobiology	dan@rna.rockefeller.edu
				Rockefeller Univ.	...cmcl2!rna!dan
				1230 York Ave.		rna!dan@nyu.edu
				NY, NY 10021		tso@rockefeller.arpa
							tso@rockvax.bitnet