Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!pasteur!agate!ig!uwmcsd1!bbn!mit-eddie!zrm
From: zrm@eddie.MIT.EDU (Zigurd R. Mednieks)
Newsgroups: comp.sys.mac
Subject: Re: Mac disk sizes
Message-ID: <8359@eddie.MIT.EDU>
Date: 2 Mar 88 21:48:19 GMT
References: <1054@ut-emx.UUCP>
Reply-To: zrm@eddie.MIT.EDU (Zigurd R. Mednieks)
Distribution: na
Organization: MIT, EE/CS Computer Facilities, Cambridge, MA
Lines: 25

In article <1054@ut-emx.UUCP> ayac071@ut-emx.UUCP (William T. Douglass) writes:
>Is there a limit in the OS or hardware that restricts the size or number of
>hard disks that you can attach to a mac II?  Thanks,
>

Volume size: This CAN get very big. The maximum allocation block size
is 2^32, and the maximum number of blocks per volume is also 2^32. Now
this isn't practical since who wants a 4GB disk buffer! At least we
are sure that we could put four billion and change reasonably sized
disk blocks on a volume. That's more than any disk, including any
optical disk, will hold.

SCSI will accomodate only 7 disks using first level SCSI addressing.
Using NuBus interfaces you could have up to the theoretical maximum of
2^16 drives (volumes).

If you had a volume with a million billion bytes on it, and your
transfer rate was 10MB/sec. it would take more than two years just to
read all the information into memory. It could keep you busy.

-Zigurd
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