ERROR_MOUNT is a state which is assigned to a drive which fails to mount for
any of a variety of reasons.  It is similar to the old UNKNOWN status which
afflicted discs which failed to mount pre-4.0.

As there are literally dozens (or even more) reasons why a disc will not
mount, it is not possible to tell via DSTAT why your disc came up in an
ERROR_MOUNT state.  However, based on your detailed description, it is
likely that when you decabled the drives from a 5.5 system and recabled them
to a 4.0 system, the drive failed to mount because the transaction manager
couldn't access the log file built on the drive.  The format of the XM log
files changed from 4.0 to 5.0 making backdating pretty darn  difficult.

In your particular case I don't think there would have been any way to
recover from the ERROR_MOUNT other than by rebuilding the volume set.  Or,
you could have put the drives back onto the 5.5 system and     stored the
files to tape and then rebuilt the drives on the 4.0 system.

Bob Denham

-----Original Message----
From: Rudderow, Evan <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Monday, September 14, 1998 7:19 PM
Subject: DSTAT Question


>Hi all,
>
>I attached a couple of 2GB C2490AM disk drives to my 917 running 5.5PP4
>just to make sure they worked; I configured them as Ldevs 33 and 44, put
>them in a volume set named "SUSPECT", and pounded on them for a while.
>Satisfied, I disconnected them from the 917, hooked them up to my 957
>running 4.0, configured them as Ldevs 31 and 32, did a START NORECOVERY
>and was greeted with a System Abort (actually my operator was greeted
>with the SA at 03:00 last Friday, so I told him to power off the discs
>and try again).  After powering off the discs the system booted with the
>new configuration intact.  When I powered on the disks however, I got
>the output shown below from a DSTAT ALL, I've looked at the 5.0 and 5.5
>LaserROM but can't find any reference to the "ERROR_MOUNT" condition
>that's shown for Ldev 31.  Anyone know what it is?
>
>Thanks.
>
>Evan
>
>
>LDEV-TYPE    STATUS      VOLUME (VOLUME SET - GEN)
>  ----------   --------    --------------------------
>  1-C3010M1     MASTER      MEMBER1         (MPEXL_SYSTEM_VOLUME_SET-0)
>  2-C3010M1     MEMBER      MEMBER2         (MPEXL_SYSTEM_VOLUME_SET-0)
>  3-C3010M1     MEMBER      MEMBER3         (MPEXL_SYSTEM_VOLUME_SET-0)
>  4-C3010M1     MEMBER      MEMBER4         (MPEXL_SYSTEM_VOLUME_SET-0)
>  5-C3010M1     MEMBER      MEMBER5         (MPEXL_SYSTEM_VOLUME_SET-0)
> 12-C3010M1     MEMBER      MEMBER12        (MPEXL_SYSTEM_VOLUME_SET-0)
> 13-C2490AM     MASTER      MEMBER13        (CLOSET-0)
> 14-C2490AM     MEMBER      MEMBER14        (CLOSET-0)
> 15-C2490AM     MEMBER      MEMBER15        (CLOSET-0)
> 16-C2490AM     MEMBER      MEMBER16        (CLOSET-0)
> 17-C2490AM     MEMBER      MEMBER17        (CLOSET-0)
> 18-C2490AM     MEMBER      MEMBER18        (MPEXL_SYSTEM_VOLUME_SET-0)
> 31-C2490AM     ERROR_MOUNT SUSPECT33       (SUSPECT-0)
> 32-C2490AM     LONER       SUSPECT44       (SUSPECT-0)
>