RT-11: ?DIR-F-Invalid directory

From: Jerome Fine <jhfine_at_idirect.com>
Date: Wed Feb 3 07:34:35 1999

>Zane H. Healy wrote:

> NO!!!! I just tried to run a SYSGEN on my RT-11 system, and I seem to have
> lost the filesystem when it started to rebuild the system. I'm able to
> boot to another partition (gotta love that WQESD controller), and I get the
> following results:
>
> .dir du2: <-DU2: is my main RT-11 disk
>
> ?DIR-F-Invalid directory
>
> Please tell me there is a way to recover (unfortuanlty I doubt there is).
> I wasn't smart enough to make backups and everything I've been working on
> was on that partition.
>
> I'm seriously bummed. However, I finally got smart and made a bootable
> TK-50 so if need be I can load RT-11 without to much difficulty (other than
> having to type in the bootstrap by hand).
>
> First I can't get TCP/IP to work, and now this.... :^( Looks like once I
> get everything back together I'll be starting on that from scratch, which
> might be good.

Jerome Fine replies:

There might be a way to recover some of the files and depending
on the state of the directory, almost all of the files that you have
modified. But, I would need a lot of information, probably a
file with the contents of the first 68 blocks on the DU2: unit.
So don't despair as yet.

1. Create a 68 block file on the good unit that you can still boot from:
CREATE DU2.DIR[68]
2. Make it a logical
MOUNT LD2: DU2.DIR
3. Copy the first 68 blocks of DU2: to the logical
COPY/DEV DU2:/START:0./END:67. LD2:/START:0.
4. Compare the logical and DU2: to be absolutely sure.
DIFF/BIN/DEV DU2: LD2:
5. Send me the file DU2.DIR via e-mail
You probably do not need the full 68 blocks since it was
very doubtful that you ever used that many. If you know
anything about the structure of a directory, then do a:
DUMP/TERM DU2:
and note where the directory information stops. The block
numbers are in octal and the dump is in octal. Even if you
know next to nothing (or even nothing), you should be able
to separate out directory information from junk or format.
The directory proper starts at block 6. If the directory is
(almost certainly) smaller than 31 segments, then adjust the
size of the file that you set up as a logical accordingly. If
you need more information, please ask.

One thing this exercise will do is to determine if there are
any unreadable blocks as opposed to blocks with bad
data. It is possible that only BLOCK 1 (2nd block on DU2:)
is bad (unlikely) and the actual directory is GOOD.

Sincerely yours,

Jerome Fine
Received on Wed Feb 03 1999 - 07:34:35 GMT