jet@karazm.math.uh.edu ("J. Eric Townsend") (01/06/91)
In article <37583@cup.portal.com> thad@cup.portal.com (Thad P Floryan) writes: >one would easily draw the conclusion that if you stare cross-eyed at or >sneeze in the same room as an Amiga the filesystem will go belly up, requiring >reformatting and reloading from a backup. You got it. I was downloading a file from work when my brother accidentally unplugged the Amiga (duh). Three hours later I've restored my drive to the point where I can go back to work. Since then, I've discovered DiskX and bought the Abacus drive book, which has allowed my to CMA a few times and not have to reinstall everything. Very few (if any) "users" will ever bother doing this. AmigaDos needs a *real* filesystem. Hopefully it's there in 2.0. Why is the FS so fragile compared to other micros? I haven't looked too closely at AmigaDos (don't even own the RKMs, etc..), but it seems that *somebody* out there will know the answer to this question. -- J. Eric Townsend Internet: jet@uh.edu Bitnet: jet@UHOU Systems Mangler - UH Dept. of Mathematics - (713) 749-2120 "I don't know that atheists should be considered citizens ... or patriots. This is `one nation under God'." -- President George Bush to an AA reporter.
jesup@cbmvax.commodore.com (Randell Jesup) (01/07/91)
In article <1991Jan5.233130.24022@lavaca.uh.edu> jet@karazm.math.uh.edu ("J. Eric Townsend") writes: >Why is the FS so fragile compared to other micros? I haven't looked too >closely at AmigaDos (don't even own the RKMs, etc..), but it seems that >*somebody* out there will know the answer to this question. FFS is slightly more fragile than OFS (but only in that recovery programs can't recover files that have lost their header block or an extension block). Of course, this helps it be 5-10 times faster too. I suspect (I don't know the MSDOS filesystem well) that MSDOS merely ignores the fact that the filesystem was unstable. I suspect if it's writing to the FAT when you reboot, you're really hosed. In other cases, the file being written may be garbage or have an unreadable sector in it. The Amiga FS knows when the FS is unstable state, so it tries to figure out what the stable state is by scanning the directory tree to build a new allocation bitmap. If a fileheader or exxtension block was hit by the power-down, it won't be able to rebuild it. Before 2.0, the FS was somewhat vulnerable to something tromping on it's memory and making it think blocks were free that weren't. This is less likely under 2.0, since the bitmap is no longer cached in memory, it's read from disk as needed. In reality, I doubt most FS problems result from programs trashing the bitmap (trashing that wild usually kills the system fast), but it can happen. Steve Beats may answer with more detailed info. -- Randell Jesup, Keeper of AmigaDos, Commodore Engineering. {uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.commodore.com BIX: rjesup The compiler runs Like a swift-flowing river I wait in silence. (From "The Zen of Programming") ;-)
david@dogmelb.dog.oz.au (David Le Blanc) (01/08/91)
Speaking of FFS, I downloaded a file called 'fastfile.lzh' which
claimed to be an FastFileSystem update.
I scanned the file, and the string (or similar)
"FastFileSystem xx-sep-90 (V 36.35)" was near the beginning.
1) Is this a valid file system?
2) Why is it twice as large as the 36.05 (1.3.2) distribution?
3) Why does the light flash on df2: when df1: is begin accessed
now that I have installed the file system in my A590?
Question 3 is a doozy!! It also happens under 2.0, and I have
a friend (a statement in itself? :-) who claims when he
accesses df1: under 2.0, his drive df2: keeps activating, and its
activity light flashed!!!
I have noticed the following :
The disk doesnt wait long at all before writing out the bitmap!
(since this a 330Meg SCSI drive, I am obviously a trusting person.)
I copies some files around, and noticed that file requesters/SID/etc
seem to be able to scan the directory many times faster..
I have been getting files with invalid protection . Ie
list shows a directory with protection '-5AZRWED' !!!!!!
Any one care to comment??
Does this FS support links created under 2.0???? I didnt want to make
any for fear or how they appear under 1.3!
Cheers.
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