[Info-vax] Anyone interested in another public access system

[Bill Pechter]

In article <gs2iit$c44$1 at naig.caltech.edu>,
glen herrmannsfeldt  <gah at ugcs.caltech.edu> wrote:
>Bill Gunshannon <billg999 at cs.uofs.edu> wrote:
> 
>> Yeah, and I remember doing SQUEEZE on my DEC disks.  
>> Do we still have to do that on VMS, I wonder?
>
>I remember writing and reading RT-11 floppies on a VAX.
>The RT-11 file system stores all files in contiguous blocks,
>requiring SQUEEZE to write large files after deleting many small
>ones.
> 
>> 1746 files, 44420 used, 10109779 free (2635 frags, 1263393 blocks, 
>> 0.0% fragmentation)
>> 19 files, 25064 used, 20286338 free (26 frags, 2535789 blocks, 
>> 0.0% fragmentation)
>> 6878 files, 289010 used, 25099511 free (5143 frags, 3136796 blocks, 
>> 0.0% fragmentation)
>> 789103 files, 79801403 used, 156703416 free (197312 frags, 
>> 19563263 blocks, 0.1% fragmentation)
> 
>> User fileserver.  Last one is the users directory.  1400 users filesystem
>> shared thru NFS on Unix systems and Samba on Windows system.  All faculty
>> and student files are here.
>
>I haven't thought of the details of the unix file system for
>a while, but if I remember this one right, it isn't quite
>the same.
>
>For systems like DOS/Windows, especially for FAT file system,
>one wants files as contiguous blocks.
>
>The unix file systems I remember allocate in larger blocks,
>such as 4K or 8K bytes.  (Likely made up of 512 byte disk blocks.)
>Large files should be contiguous 4K or 8K blocks, but that is
>inefficient for small files or the last blocks of larger files.
>To handle small files, the 8K blocks are fragmented and kept
>track of separately.  The number you see as frags is really
>the number of small files stored in fragmented blocks.
>
>-- glen


That's SYSVRel4 "Unix File System" -- a renamed Berkeley Fast File System
added only in SVR4 and later Unix systems from AT&T and their sublicensees.

Bill

-- 
-- 
Digital had it then.  Don't you wish you could buy it now!
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