Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!uakari.primate.wisc.edu!aplcen!haven!mimsy!chris
From: chris@mimsy.umd.edu (Chris Torek)
Newsgroups: comp.unix.questions
Subject: Re: How to do bad block replacement on RA81 under 4.3-tahoe?
Keywords: ra81 bad-block
Message-ID: <20370@mimsy.umd.edu>
Date: 24 Oct 89 18:47:40 GMT
References: <1008@asuvax.asu.edu>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 32

In article <1008@asuvax.asu.edu> system@asuvax.asu.edu (Marc Lesure) writes:
>I thought the 4.3-tahoe device driver for the ra disk series did bad block
>replacement ...

Nope, sorry.  It was `too hard' (not to mention practically impossible to
test).  Maybe someday. . . .

>The man page for the uda says to get DEC to replace the bad block via EVRLK.
>Since we are not on DEC maint., is there another way of doing this?

Steal a copy of EVRLK :-)

Incidentally, I am still not sure of the name.  There *is* a standalone
diagnostic that will do it, though.  (There may be several.)

>With the RM05 disks I used 'badsect', but this doesn't seem to work with
>the RA81.

`bad144' is for DEC STD 144 disks (e.g., RP06, Eagle on Massbus, etc.).
`badsect' should work but is not very nice.  I have never used it myself.

If you are really ambitious, add an ioctl to allow `replace' commands,
and write a user-level program to do it.  You will have to let the
program write past the `end' of the disk (either via another ioctl,
or by `adjusting' the size of, e.g., the c partition).

The algorithm used for replacement can be found in the VMS source.
(eeuck)
-- 
`They were supposed to be green.'
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@cs.umd.edu	Path:	uunet!mimsy!chris