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The 'standard' mother board is designed to run up to 4 hdd or cd in any combination. just wondering what peoples view is on how many hdd's and cd's realisticly need to be searched for in a basic desk top OS.

I did at one time have several systems with 24 drives. That was a long time ago when drives were small and I needed 40+gig. What seems a reasonable number for an OS for today?

My bog standard, pretty old motherboard has 6 SATA ports (There are an additional 2 which aren't soldered down on my model - only on the higher end SLI version). It also has the now-standard single legacy ATA connector.

Realistically? Searching disks is no problem. They're not that difficult to find (OK, except perhaps USB/Firewire mass storage devices)

We have 4 computers in general use in the house, 1 for my wife and three for me. A quick run down in terms of drives:

Her laptop has a 80GB hdd and a dvd-rw drive
My old laptop has a 120GB hdd and a dvd-rw drive
My new laptop has a 500GB hdd and a blu-ray reader / dvd-rw combo drive. Can't find specs for blu-ray though
My main box (desktop) has:
- 3x250GB Samsung SATA hdd, currently 2 in RAID-1 and one empty.
- 1x1500GB Seagate SATA hdd
- 1x40GB Maxtor PATA hdd
- 1 dvd-rw drive PATAPI

I'd say that just scanning for the present PCI adapters & the drives attached to them should be sufficient. Why limit it to an arbitrary number?

I got a machine with 5 hdds + CD, one with 6 hdds + CD, both SCSI-based servers. My brother has one with 10 permanently attached storage devices thanks to putting all old stuff ever collected in one machine rather than recycling (HDDs ranging from 8GB to 1TB; mixed SCSI 5x, ATA 4x and USB 1x), and my drive king is one with 16 HDDs, a CD and a tape unit (again all SCSI, but this one isn't an x86).


Don't worry, I have for many more "I assume that..." a counterexample

Enumerate until you can no longer enumerate, it's not like they're mapped at fixed I/O positions on modern systems.. and with USB/eSATA and friends, they can even show up and disappear randomly.

Don't even need eSATA. I have hotplug SATA bays (Admittedly currently connected to a non-hotplug controller, but hotplug works fine on my desktop - in fact, I had to use it once during a raid array rebuild)

Fun, and yes, that works too.. the point being make sure your design is resilient to crazy disk swappers like Owen.

What sort of specs are you seeking? from a driver perspective, it should be similar to any other CD/DVD drive.. shouldn't have to deal with any decryption aspects for video discs, can let userland deal with that.


Exactly.

I noticed that SCSI MMC (which is what atapi cdrom's use) has specific featureset configuration stuff for just about every type of CD and DVD that I've ever heard of, plus some 5 that I didn't. I can't find a newer MMC spec (using MMC-4) and it doesn't list any blu-ray stuff. Other than treating it like a huge cd, any ideas?

Depending on what I've got cabled to my laptop at any given time, that could be 1-4 hard drives, 0-2 CD/DVD drives, and about as many USB sticks as I can find USB hubs for.

Bottom line: +1 to "don't arbitrarily limit the number".

Blu-Ray drives should be MMC-5/6 compliant.. public documents are available on t10.

http://www.t10.org/ftp/t10/drafts/mmc5/
http://www.t10.org/ftp/t10/drafts/mmc6/

EDIT: Seems those documents are invalid, anyway, they want you to fill out a form these days.

http://www.t10.org/cgi-bin/ac.pl?t=f&f=mmc6r02g.pdf
http://www.t10.org/cgi-bin/ac.pl?t=f&f=mmc5r04.pdf

EDIT: Uhh, Actually, it seems MMC-5 requires a membership? you can download the MMC-6 draft document though, the other document is available elsewhere if you're really interested.

Thank you every one for your input. Very good points, and there are still people with as much storage stacked up as they can. Guess some things don't change over all, just the details. Guess the answer is to support what I need to in the core and leave the door as open as I can for the drivers.