SUMMARY: backup on optical/cd media instead of tape

Date: Wed Apr 10 1996 - 00:52:20 CDT

I had asked a question to this group about backup on writeable optical
drives instead of tape.

I got 4 responses and 1 metoo. 2 of the respondents had been using
optical drives for backup. Thanks to all who replied.

For now, I have decided to go the 4mm tape route for the following reasons

1. I already have available on-line disk duplication, so the need for
yet another disk-like backup copy is not that strong
2. The cost of media is still quite hefty compared to tape - at $70/1.3GB disk
   vs $20 for 4/8GB DDS2 DAT tape
3. Tape has higher capacity (4/8GB with DDS2 DAT vs 1.3GB for MO disk)
4. The optical drives are in the $2000+ range and DD2 DAT drives are in
the $1000 range

Here is my original message:

Subject: backup on optical/cd media instead of tape


My question(s) have to do with backup - specifically to ask for people's experiences with backup to writeable optical media. I am trying to figure out if I can avoid tapes entirely (for one I dont currently have any tape drives, for another, it appears just too painful to recover from tapes)

My backup needs are relatively simple. There are 3 Suns, running SunOS4.1.3_U1 and SunOS4.1.4, each with about 500MB-1GB of data, including the OS.

Currently the backup consists of completely duplicating the file system of each machine onto a separate (vanilla,magnetic) hard disks on each machine (a nighly incremental dump). The external disks have been made bootable.

I felt it might be worthwhile to have some more persistant storage of the data as well in case the original and duplicate disk both crash.

The questions: 1. What writeable optical drives would you recommend - both in terms of drive quality/compatibility with Suns and manufacturer support? I am aware of the Artecon Lynx, HP Surestore 1300t and Pinnacle (model?)

2. Are there any special compatibility issues with Sparc4, Sparc 10? I assume these drives come with vanilla SCSI2 and should be mountable the Sun as a usual filesystem - is any extra software needed?

3. Is there any problem with making these drives bootable?

4. Is this idea of optical backup just fatally flawed compared to good ol' tapes in some way I am not considering?

Please respond to, I will summarize.

Thanks, (although the emailaddress appears to indicate I am somehow related to netcom's networking group, I have nothing to do with netcom) ---------

The responses:

--------- From: (Martin Achilli)

Hello, we have been using optical rewritable drives for about 5 years now, we have used various models of drive:

SONY SMO 501C with 600Mb disks bought 5 yrs. ago HP/Maxtor tahiti II with 600Mb disks bought 3 yrs. ago Maxtor T3-1301 with 600Mb disks and 1.2Gb disks bought 1.5yrs. ago

we have had all sorts of problems with the Sony drive, less problems with HP/Maxtor drive and very few with the Maxtor drive.

We have lost some data with the Sony drive and the HP/Maxtor drive, none with the Maxtor drive, although we have not been using it as long as the other two.

We stopped using the Sony drive one year ago.

I have encountered many problems with the way SunOs 4.1.X handles removable media. This aspect is a major issue in the use of EODs, since the error recovery mechanisms of SunOs for disk drives (EODs are seen as normal disk drives by SunOs) is not very good and when problems occur you have to reboot the machine.

I can answer more specific questions if you want, personally for the type of work and needs that we have I will not recommend using EOD drives in the future. The drive itself is expensive, OS support is not good enough, the cost/megabyte including the initial cost of the drive is high and lastly the use of EOD drives simply adds a level of complexity in the data storage hierarchy (HD > EOD > TAPE).


---------- From: John Justin Hough <>

1. I have a HP 1716T and it is reasonably quick. You must use it as regular had disk and not like a CDROM though.

2. No. but you might just get a prestoserve because this media is still very slowwww to write on.

3. No - see #1

4. It is more expensive media, but easier to find the bit of data you are trying to recover, so you might say that if it takes less of your time it may well be worth it. Data stored on MO devices may also may be longer lived than on Tape based magnetic media.


------ From: Alexander Greiml <> Hmm, I can't tell You anything about Your first three questions, but to question 4 I can tell You, that these optical media have quite limited storage capacities, aprox 700M in comparison to the good old tape with capacities in between 4 - 16 GBytes (Enough, not to stay open all night to change media). And if as You said Your backups are done nightly, it shouldn't matter if the tape-drive is a little slower then other storage media.

In case Your low on budget, (as anyone is, I think) the tape seems to be the better alternative.

Hope my comment will help

Alexander ---------

From: Philip Kao <> Artecon offers a line of MO drives and software for your needs. With ArteEOD, you can use the MO as a removable hard disk, thus preserving your information of the other hard disks intact without needing dump or tar.

Alternatively, you could also backup directly to the optical disks using another software product called Artecon/DNB. This will write extended tar formatted files onto the optical discs.

-phil --------

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