Abi Admassu asks:

> We are running ADSM V1R1L12 on MVS.  Our mainframe group recently moved the
> recovery log and the server databse to RAMAC.  Is there any need for
> mirroring the database and recovery log if both are on RAMAC?  Other than
> sudden power outages, what other scenarios corrupt the database?  Any input
> is greatly appreciated.

The purpose of mirroring the database and log is for protection against media
failures (i.e. head crashes). Mirroring the database does *not* protect
against corruption. By "corruption", I mean a *logical* failure in the data
(broken pointers, invalid data values, etc.). An incorrect record written to
one copy will also be written to the other copy, so the mirroring is of no
help against corruption.

This being the case, any fault tolerant device should protect you from media
failures, and your database should be as safe on it with one copy as it
would be on traditional (non-fault tolerant) DASD with two copies.

Andy Raibeck
Connecticut Mutual
203-987-3521