news@wcom.UUCP (News Administrator) (03/28/85)
My IBM PC/AT Xenix (System III) system went wierd last nite, resulting in the /usr/bin directory being transmuted into an unreachable directory. What happened was that the `i' in `bin' was turned into a null, and no matter what I tried to do, the system kept complaining that 'b' was non-existant. I ended up remaking the filesystem from a backup. Was that the only solution, or does someone else have a better way? Jim Scardelis
ignatz@aicchi.UUCP (Ihnat) (03/29/85)
Jim wrote that his IBM PC/AT went wonka, put a very anti-social null in place of the 'i' in the name of his /usr/bin directory name, and asked if there was a better way to recover than to reformat & recover. Yep, but you ain'ta gonna like it. ADB. Yes, folks, just adb that raw hard disk device (unless you're lucky enough to have a ported version of 'fsdb'...) Using adb, you can do everything from twiddle the superblock to fiddle the directory. Only trouble is, if you're not very comfortable with the file system structure, then this could be more painful than the recovery. (It isn't for me, but Altos diskette drives are notoriously slow) It really does help to know the block breakdown scheme for the driver (i.e., blk => cyl/head/sector), although you can still do it without that. This is *really* getting dirty, -- Dave Ihnat Analysts International Corporation (312) 882-4673 ihnp4!aicchi!ignatz
chris@umcp-cs.UUCP (Chris Torek) (03/29/85)
Adb (or---if you're lucky enough to have one---a file system scribble
tool program) can correct mucked up directory names.
However, (and I'm not sure if works for System n, where 3 <= n <= 5),
there is a better way: if /usr is corrupted such that /usr/bin is now
/usr/b^@n, then "ln /usr/b" to "/usr/bin". This works iff your namei
code doesn't compare the entire name, including all trailing nulls.
Unfortunately, most do.
As a third alternative, you can always "mkdir /usr/bin" and restore
only the files that go there (assuming you have plenty of disk space),
then remove the "/usr/b^@n" later.
--
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 4251)
UUCP: {seismo,allegra,brl-bmd}!umcp-cs!chris
CSNet: chris@umcp-cs ARPA: chris@maryland