[Info-vax] Reconfiguring VMS 6.2 - Shadow set question

[Jan-Erik Soderholm]

supervinx wrote 2012-10-22 00:28:
> $ mount dsa0: /shadow=($1$dka100:,$1$dka200:) /system  V47701_sys
> %MOUNT-I-SHDWMEMSUCC, _$1$DKA100: (V47701) is now a valid member of the shadow s
> et
> %MOUNT-I-SHDWMEMFAIL, $1$DKA200: failed as a member of the shadow set
> -SYSTEM-W-NOSUCHDEV, no such device available
>
> -----------------------------------------------------------------------------
>
> $       mount dsa1: /shadow=($1$dka300:,$1$dka400:) /system  Oracle
> %MOUNT-I-MOUNTED, ORACLE mounted on _DSA1:
> %MOUNT-I-SHDWMEMSUCC, _$1$DKA300: (V47701) is now a valid member of the shadow s
> et
> %MOUNT-I-SHDWMEMFAIL, $1$DKA400: failed as a member of the shadow set
> -SYSTEM-W-NOSUCHDEV, no such device available
>
> -----------------------------------------------------------------------------
>
> V47701: sho dev
>
> Device                  Device           Error    Volume         Free  Trans Mnt
>   Name                   Status           Count     Label        Blocks Count Cnt
> DSA0:                   Mounted              0  V47701_SYS      863790   323   1
> DSA1:                   Mounted              0  ORACLE          390150    17   1
> $1$DKA100:    (V47701)  ShadowSetMember      0  (member of DSA0:)
> $1$DKA300:    (V47701)  ShadowSetMember      0  (member of DSA1:)
>
> -----------------------------------------------------------------------------
>
> DKA200 and DKA400 are missing.
> So:
> 1) Can I remove the shadow sets ? The first involves the system disk ...


Yes you can. But for the short term, you don't have to do anything!

There is no problem running shadowing using a single disk, VMS is
happy anyway. You will of course not get the extra availibilty,
but that you know already.

Your system is currently running just fine, not ?

> 2) Or it's better and safer to remove only DKA200 and DKA400 from the shadow ?
>

If they definitely are "gone" you can edit the MOUNT command above
and remove the DKA200 and DKA400 references.

But keep the DSA0 and DSA1 devices for the time beeing!
VMS runs happily with single disk shadow sets.

Then, *after* you have done all analyzes of your startup scripts
(and whatever) to find all references to DSAx, you could modify
the MOUNT commands and remove the DSA devices. If you're lucky,
it's only a single place to change. If you're unlucky, there are
many places (command files and other) where the DSAx names
are used, and then you can deside to just continue running
using the DSA names (but with DKA200/400 removed from the
MOUNTS commands). Your decision.

If this was *my* system, I'd rather look at getting
DKA200/400 back in service again...

Jan-Erik.


> Thanks !
>