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May 2001

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DVD RAM Disks and eCS, OS/2

By: Lothar Frommhold ©April 2001

Recordable and rewritable compact disks (CD) and the necessary drives to work with them are now fairly standard; excellent software is available commercially from RSJ, and even free software (CDRecord) can readily be downloaded. However, the CD capacity is limited to something like 650 Mb, which in our times of multi-Gb hard disks is often not sufficient for backups, archiving of graphics files, etc. I decided therefore to look into rewritable DVD formats that might work under eCS.

At present, a number of DVD RAM drives are somewhat affordable; mail-order houses in the USA offer models from Panasonic and Hitachi for about $550, and from Creative Labs for a little more than half that price. So I decided to try archiving graphics files, and do daily back-ups, on DVDs. The DVD RAM format is especially suitable for archiving; it uses a phase-changing, optical recording technique whose data life is believed to be in the hundred-year range - that is much superior than some of the CD-RW media or even tape. There are several other DVD recording techniques; suitable drives that were commercially available for the competing techniques cost at this time several times that amount and, consequently, I simply ignored them. My feeling was that these competing formats did not offer a significant advantage for my anticipated uses. DVD RAMs at present offer 2.6 Gb capacity per side; double sided disks are available that store a total of 5.2Gb; disks with three to almost four times this capacity are announced by several manufacturers for the near future.

Full DVD/UDF support, that is for formatting, reading and writing of Digital Versatile Disks (DVD) RAM data disks using the Universal Disk Format (UDF), is provided with Warp Server for e-Business (WSeB or Aurora). Updates to version 1.0 of the installable UDF system are available for Software Choice (SWC) subscribers, e.g., UDF version 1.5; version 2.0 is to be expected in the near future. Some DVD/UDF support for reading of DVD RAM data disks, and also for writing of suitably preformatted, rewriteable DVD RAM data disk (but not for the formatting of such disks) is included with the Merlin Convenience Package (MCP) (the thin client version) and eComStation (eCS), preview1. The UDF version provided with MCV and eCS, preview 1, is 1.0.

UDF Support Installation

Presently, all DVD RAM disks I was able to buy from standard PC supplies vendors were unformatted. In other words, writing DVD RAM disks is provided only for WSeB software users, but not for the client OS/2 and eCS packages. A somewhat outdated package to format DVD RAM disks is available from Hobbes (UDFFILE.ZIP) which can be easily installed in a client system. Unzipping the UDFFILE in a convenient subdirectory will give you four files: DVDINST.EXE, OS2CDROM.DMD, UDF.IFS, and README.TXT. In addition, there will be 14 language specific subdirectories that contain UUDF.DLL files.

The UDFFILE.ZIP from Hobbes has three files which you need, plus the installation file DVDINST.EXE and a README.TXT. The names of these three files are OS2CDROM.DMD, UDF.IFS, and UUDF.DLL. Files with identical names come with MCP and eComStation, preview 1, but at least some of these files - most notably OS2CDROM.DMD - differ from those of the Hobbes zip file. My system crashes when I try to format the DVD, unless I have the Hobbes files active. (The installation with DVDINST saves the original files with the extension .SAV and put the files from the Hobbes package in their place.)

From a command line, change to the directory that contains the four files and type DVDINST. After a few seconds, the installation is complete. A log file is written to that directory. You must shut down and restart your computer.

The README.TXT from the Hobbes UDFfile.zip lists the DVD RAM drives that are supported ¹; I could not buy any one of these supported drives at a reasonable price, but the Hitachi drive I bought worked anyway (and the other drives mentioned above may possibly work, too).

When you restart the computer, make sure your DVD RAM drive is connected and turned on. I put a new, rewritable DVD RAM disk in the drive and use an external SCSI Hitachi GF2050 DVD RAM drive with an Adaptec 29160 UW SCSI card, to which several other externals are also connected (a scanner and a CD burner). Click on the DVD drive icon and lock the disk, by clicking on lock disk on the menu of that drive. Next, on a command line, type

where d: is the DVD RAM drive; this command formats the disk with the UDF format, which takes but a few seconds. Now use the DVD disk like any other disk: write and read without further ado - that is all! Don't forget to click on Unlock disk of the drive menu, when you want to take the DVD out, or to turn the DVD over (two-sided disks).

With this UDFFILE package, reading (and also writing) is slow; With my Hitachi drive I presently write at a rate of 100 kb/s, when commercial UDF drivers for windows are available that have much higher speeds. The UDF version is the same that comes with MCP and eCS, namely 1.0. More recent versions of the installable file system, UDF version 1.5 and soon version 2.0, are available for the WSeB and SWC (server) subscribers, that should significantly increase writing and reading speeds.

Am I happy with my daily back-ups and the archiving options on DVD RAM?

The answer is a qualified YES. It works flawlessly for me, albeit the writing is very slow (100 kb/s) with UDF, v1.0, so that back-ups must be done after the daily number crunching has ended, in the wee hours of morning. Reading speeds seem a bit slow as well.

I did not have to purchase any new software to read, format and write DVD RAMs, but I surely could not help to notice that commercially available software for the Windows operating system is way superior in terms of DVD reading and writing speeds.

The DVD RAM disk is completely integrated into the eCS/MCP system and is accessed just like any other disk of your computer; programs, such as the file commander (a Norton clone), and standard copy/move/delete commands work just like you would think they should. DVD RAMs surely are most valuable storage options for me, even when I know there is an enormous margin for improvement. The Windows drivers (which come at a price of roughly $75, for example, from Software Architects, with UDF,v.2.0) are much superior in terms of speeds, if nothing else, unless you are already using the WSeB/updates that are not available under MCP and eCS. But there is always hope that IBM (and eCS?) make available the state of the art software that we all need, eventually.

Note 1: The readme file from UDFFILE.ZIP states that the following DVD drives are supported:

Article References:
UDFFILE.zip on hobbes: http://hobbes.nmsu.edu/cgi-bin/h-search?key=UDFFILE

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