RAID for your Amiga

[AMC258]

http://cgi.ebay.com/Mylex-DAC960S-SCSI-to-SCSI-RAID-CONTROLLER_W0QQitemZ230155966443QQihZ013QQcategoryZ39968QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

I have one of these on my A3000UX.  It is the best possible solution for SCSI RAID on an Amiga that I've seen so far.  I've been using mine for years with minimal problems.  The only problems I've had are probably due to the fact that mine spent many years in a hostile environment.

You can use up to 28 (I think) drives on 4 channels, and I don't know how many LUNs (I haven't hit the limit yet).

If you do get this one, let me know.  The manuals and firmware are not available anymore.  The one on eBay has newer firmware than mine, and I'd gladly trade my setup expertise for a copy of that downloadable firmware. :-D
The newer firmware supports 20Mb synchronous, mine only supports 10.  The newer one also has some bugfixes.

[alexh]

AMC258 wrote:
The newer firmware supports 20Mb synchronous, mine only supports 10.

Internal A3000 SCSI controller only supports about 1.5MB/s average 3MB/s peak so it doesn't really matter ;-)

How do you handle enclosure managment with this? Rebuilds etc. All done with the LCD and the buttons on the unit?

Which RAID modes does it support? RAID1 only? RAID5?

[mdivancic]

How's it mounted? Internally or in a stand alone box?

[odin]

It looks like it could fit in two 5,25 inch drivebays

[AMC258]

It's the original full height "5¼" form factor.  So yes, it takes up the same space as two A2000 floppy drives.  Mine does RAID 0,5, and 6.  I'm not certain, but I think the newer firmware supports RAID 1.  It transfers to my Amiga at 20Mb/s synchronous, it's the individual drive<>interface speed that changes with the firmware update.

All functions can be handled through the panel.  It actually works really well except if for some reason you have errors on all your drives on startup, then the problem is the controller trying to sort out the errors takes priority over the buttons and it can take a long time to do anything.  Best then to power all the drives off and wait for the errors to time out.  This should never really happen though.

It also has a serial interface to connect to a computer for configuration/administration, requiring MS-DOS.  I have never tried it.  I guess it never occurs to me these are just the sort of things PC-Task is actually useful for.  I haven't found there's anything I can't do through the panel.

Here's a picture of mine:


I'm fortunate enough to have this really nice enclosure.  But, frankly these are NOT hard to come by!  I actually have another RAID enclosure WITH drives that I got for free and don't use.  It's an old IBM server that got junked because the CPU is outdated!  I'm sure these should be easy to find.

If I had $150, I'd buy the controller on ePay in a heartbeat and set up a RAID array on one of my other Amigas.

[alexh]

AMC258 wrote:
It transfers to my Amiga at 20Mb/s synchronous

Then you must have a Cyberstorm PPC/MKIII with Ultra Wide SCSI. There is no other SCSI controller for the A3000 (or for that matter any Amiga) that can do that rate.

[AMC258]

Yes, CSPPC.  But, it doesn't matter because the data transfer rate is not that fast.  That's just the clock speed.  Maybe the data transfer rate will better approach that with OS4.0:idea:

[alexh]

AMC258 wrote:
the data transfer rate is not that fast.  That's just the clock speed

??

[AMC258]

The CSPPC SCSI controller connects to the RAID at a synchronous rate of 20Mb/s.  But, the OS cannot keep up.  So, you cannot transfer a file at that rate.

It's like having a conveyor belt pass you at 1200 inches per minute.  It's traveling exactly fast enough for you to place exactly one Amiga 1200 on the belt every second.  But, there's no way you can place them on there that fast, so there are gaps between the A1200's. :crazy:  The belt transfers A1200's at a rate of 60 per minute, but you can only deliver 12 per minute to the lucky person on the other end of the belt.