stevea@idunno.princeton.edu (Steve Albin) (04/12/91)
We've had a strange error occur when using a NeXT
floptical disk, and would appreciate hearing reactions
or similar experiences from others.
Here's the situation: The programs in use were run on a Sun
Sparcstation SLC using an NFS-mounted NeXT floptical as the
home of a file system that underwent VERY HEAVY use --
hours of non-stop, as fast as the floppy-controller would let
it: reading; erasing; extensive file creation; and directory
movement across symbolic links (but all within the single
floptical disk file system). The NeXT machine used is a
couple of years old, with recent upgrades to the new system
board and operating system. The floptical drive seems to work
fine (I think it was replaced several months ago), except for
this:
After this heavy use, we find the file system on the floptical
to be thoroughly corrupted. Directories that should have been
created are not there. There are duplicate listings for directories
that should only be defined once. Running fsck there are many,
many "EXTRANEOUS HARD LINK TO DIRECTORY" errors, with many
of these listing directory names that consist of what should be
an intended name except that an extra character has been added.
For example, hard links were found to "net-news-readerZ",
"screen-testd", and "tn-048:". In all cases the final character
("Z", "d", and ":") was mysteriously appended to a directory name.
It would then take several iterations of fsck to clean up the disk.
Repeating the program after cleaning the disk would reproduce
the problem in general, but not identically (different hard link
errors).
Our resident guru ("bless the water that he walks on") has
diagnosed the problem as caused by an unreliable storage medium
that is prone to errors (the floptical). All indications are that he
is right -- we made space on another NFS-mounted disk, this time
a hard disk on another Sun, and repeated the program a couple of
times without errors.
The implications are troublesome (at least to some of us). We have
used floptical disks for many critical backups, and would hate to
write them off as unreliable without being certain. Of course we
would hate even more to need to restore from one and find that it
WAS unreliable.
Any reactions or similar experiences?
Thanks.
Steve Albin stevea@pucc.princeton.edu
STEVEA@PUCC.BITNETizumi@mindseye.berkeley.edu (Izumi Ohzawa) (04/12/91)
In article <8184@idunno.Princeton.EDU> stevea@idunno.princeton.edu (Steve Albin) writes: >Here's the situation: The programs in use were run on a Sun >Sparcstation SLC using an NFS-mounted NeXT floptical as the >home of a file system that underwent VERY HEAVY use -- [ much stuff deleted ] >we made space on another NFS-mounted disk, this time >a hard disk on another Sun, and repeated the program a couple of >times without errors. It seems that you haven't done a critical test, which is to use NFS-mounted NeXT hard disk from Spastation SLC. Izumi Ohzawa [ $@Bg_78^=;(J ] USMail: University of California, 360 Minor Hall, Berkeley, CA 94720 Telephone: (415) 642-6440 Fax: (415) 642-3323 Internet: izumi@violet.berkeley.edu NeXTmail: izumi@pinoko.berkeley.edu