Summary: r/w optical disk comments request

Date: Sat Aug 08 1992 - 14:09:56 CDT

Here's the longish (170-line) summary of my optical-disk inquiry. There's
an executive summary near the end.

On 20 July I asked about read-write optical disks for Suns; specifically,
how to allow users to mount and umount the disks, and whether non-SunOS
drivers are necessary or acceptable. I have received replies, all of
them helpful, from: (George Planansky)
daniel@CANR.Hydro.Qc.CA (Daniel Hurtubise)
dwb@carto.ssd.IMD.Sterling.COM (David Boyd) (Billy Barron) (John) (Doug Neuhauser) (Scott Crosbie)
srinivs@thuja.FSL.ORST.EDU (Satish Srinivas) (Dunstan Vavasour)
long-morrow@CS.YALE.EDU (H. Morrow Long) (Irene Barg) (Nancy Voorhis)
bmskc!moe!paul@uunet.UU.NET (Paul Evan Matz)
kalli!kevin@fourx.Aus.Sun.COM (Kevin Sheehan)
Edward.Milstein@West.Sun.COM (Edward R. Milstein) (Peter Baumann)

Many thanks to each of you.

Peter B. sent me a preliminary complilation of the responses he got from
a similar question (which I missed), and I have also reviewed his final
summary, which was posted.

In all, the following names were mentioned, in greater or lesser depth. The
vendor and manufacturer names are confused in many cases, maybe because of
direct and channel sales of the same drive and reseller name branding.

Artecon: Sony, Artecon and Ricoh drives, plus ArteEOD software.
Unison: Opti/MAX.
Pinnacle: Sony, PMO-650, REO 600MB and Micro 650 drives.
MaxOptix: Tahiti, Tahiti 2.
TenX Technology: Tahiti, OptiXchange, plus the "Optical Conversion Unit".
General Systems & Software Ltd: GS3100.
Also Alphatronix, Unbound, IOMEGA Lasersafe, Bernouilli and "LMS 520" drives.

Non-root users mounting the disks appears not to be a big issue; several
responses included or mentioned (apparently simple) suid-root code to do
this, and one said just to make the /dev file permission 775, although the
newfs operation that is required on each disk on some (all?) drives remains
an open problem. Artecon's software, which they ship with their drives,
is very well liked by everyone who mentioned it: "...users can ... format,
partition, newfs, mount, umount, etc." [Irene B.]

* Comments on the drives:

The early Tahiti drive caused a lot of problems for people. One site said
they found that two drives of the same model couldn't reliably
interchange media, and someone says it didn't use a standard media format
anyway. The Tahiti 2 (not II) is apparently better liked, although the
only extensive comments I saw on it were in Peter B.'s summary, and it is
in fact the drive he says he'll go for. It has decent throughput (he
quotes benchmarks of 560KB/s reads, 240-310KB/s writes) and has a 1-GB
mode in addition to the ISO-standard 650MB and 594MB modes. Artecon Canada
literature on the Tahiti 2 says it reads at 250KB/s and writes at 600.
(Some referred to the Tahiti as a Maxtor drive, but the literature I have
says it's by MaxOptix. It apparently uses Maxtor media for the 1-GB mode.)

The Sony drive is clearly regarded as the standard of reliability, but
seems to be the slowest drive around; the same benchmarks Peter quotes show
the Sony at 150-230 KB/s reads, 70 KB/s writes, and other quoted benchmarks
for the Sony range from 40 to 60 KB/s.

Pinnacle is really bragging up their new PMO-650 "optical hard drive" as
fast enough to compete with Winchester disks. One respondent says they
quote sustained transfer of 1.4 MB/s, but the literature they sent me shows
transfer rates (using MS-DOS XCOPY and done by some named testing lab) of
108 to 140KB/s. The same table shows this as almost twice the rates of a
Seagate 350MB hard disk, and puts a Sony optical disk at 20 to 27KB/s. But
the few people that mentioned Pinnacle have had problems in the past, and
two said that Pinnacle is ineffectual to deal with for problem resolution.
They are advertising the drive as "Plug and play ready for IBM/AT/XT/PS/2
and compatibles, MAC, SUN, HP, Silicon Graphics and others." When I talked
to them, they seemed fuzzy on Unix issues like non-root control, but
definitely said they have no special drivers for it. The only person who
said they actually have a PMO says it's great, needs no drivers, and is
fast. Earlier Pinncacles (REO 600?) are not especially quick.

One of Peter B.'s respondents says that NONE of the MO drives on the market
is reliable except possibly a new Ricoh unit that has some special dust
protection. Artecon advertises the Ricoh RO-5031E as having sustained read
& write transfer rates of 950 & 475 KB/s, which seems very fast.

On media, one comment from a disgruntled early Pinnacle user in Peter's
compilation says that only the Sony platters are "half decent" and others
(3M, DOT, "Verbatum" [sic]) are not very good. I had not heard of DOT, but
it's what Pinnacle recommends for the PMO.

The scoop on media standards appears to be: there are ISO standards for 595
("600") and 650MB, using 512 and 1024 bytes/sector media, respectively, and
some drives (eg., Tahiti 2) have a 1-Mb mode using special media. In all
cases you get half the stated capacity on each side of a disk, which you
remove and flip.

* On drivers, I've heard the following:

The early Pinnacle drive required a kernel rebuild to install a driver
despite their "plug and play" claims, and they provided a too-simple script
to attempt to do the rebuild (gasp!). Another user says their Pinnacle REO
600MB drive required drivers under SunOS 4.1.1, and it works ok. The new
PMO does not use a special driver.

The only thing a driver does, says one person, is get him an eject ioctl.
There are still "problems" with write protecting disks. Don't know what
drive this is with. Alphatronix, Unbound, Iomega and Bernoulli drives use
the Sun sd driver, and the Tahiti 2 needs a special driver only for use in
the 1GB mode.

One user's Sony drive came with a driver, which works well. A local Sony
vendor (Open Storage Solutions, which is what DILOG Canada is now that
DILOG broke up) says that for the Sony, some lines need to be changed in a
device parameter file under SunOS 4.1.1, but 4.1.2 is ok as is.

TenX has an "Optical Conversion Unit" which "[makes] the optical disk
look like a regular Winchester drive ...[and] makes WORM media appear to
be R/W ... and ... does data compression in real time, transparently...".
Obliviates the need for special drivers. You know, I've seen this marketed,
I think for WORM drives. Not really what I'm looking for.

I was trying to avoid special drivers because of past experiences with
hassles at OS upgrade time. It looks to me like the latest drives don't
need special drivers - at least with the latest SunOS releases.

* Conclusions

I am aware of the recent Sun Expert review, but I wanted to hear hands-on
stories. You know, Sun Expert is a great mag, but neither it nor the other
Unix trade magazines ever seem to do the critical lab tests that PC
Magazine, etc., do for the DOS world.

My choices among the major units seem to be as follows. I'm showing recent
quotes in round figures. C$1 is about US$0.83 right now.

Vendor/Drive/$ Pros and Cons
--------------- --------------------------------------------------------------
OSS[Dilog]/Sony Pro: I like the vendor; reliable & well-liked drive; cheapest.
C$4000 Con: Very slow compared to newer technology.

Pinnacle/PMO650 Pro: Fast.
US$4000 Con: Vendor and previous models unliked by some; vendor
                     remote (customs hassles, especially on repairs) and
                     apparently short on Sun support & expertise; this model
                     not yet in wide use.

Artecon/Ricoh Pro: Apparently fast; some promise of reliability; comes with
C$4700 well-liked Artecon s/w; large vendor with Sun expertise.
                Con: Drive not well known.

Artecon/Tahiti2 Pro: Not too slow; has 1-GB mode; Artecon benefits as above.
C$5900 Con: Pricey; previous model unliked by some.

The bottom line: I have ordered the Ricoh unit from the local Artecon
outlet. They say that the ArteEOD software includes a driver, and that
they're committed to supplying a Solaris 2.0 driver.

If anyone wants to know how it works out, drop me a line in a week or two.

Many thanks again,

Chip Campbell
Sunnybrook Health Science Centre (University of Toronto)

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