Fatal Disk Error urgency [1]

[RWK@FUJI.ILA.Dialnet.Symbolics.COM (Robert W. Kerns)]

    Date: Tue, 12 Jun 90 13:33:31 EDT
    From: aboulang@BBN.COM
    As a survivor of a crash where the LMFS would not come up, one can do
    some things if you can *NOT* get the LMFS up. Find out where it is
    stopping in the bring-up process. In my case, it was stopping in
    bringing up one of the partitions.  My ultimate problem turned out to
    be a bent pin on one of the disk drive cables. 

Yes, I should have emphasized more strongly that if the hardware is
broken, it should be fixed before attempting any filesystem repairs!

In particular, if you suddenly get a lot of ECC errors in different
places, some hardware is broken.  Cabling, IO board, IO Paddle, disk
drive electronics, and power supply are all possibilities.

If part of the data needed to bring up LMFS is damaged, there ARE
things which can be done, but they pretty much need to be done by
someone who understands the LMFS on-disk structure.  Maybe you can
educate yourself, but it's not easy; hence my advice to either reload
or call an expert.  (If you're already an expert, that's the easy part.)

If the LMFS you're trying to bring up has your only copy of the LMFS
sources, it's a lot harder to figure out how to fix the problems.

If anyone is interested in becoming an expert by fixing these problems
themselves, the place to start is the DEFSTORAGE definitions of the on-disk
structures, in SYS:LMFS;FS-DCLS.LISP.