Co-Existence of CMOD old & new versions

[sandeepveldi]

Hi All,
Can any one please let me know if two different versions of DB2 & CMOD can co-exist on the same server and also sharing the same set of data?

DB2 Current Level:  v8.1.1.156
CMOD Current Level: v7.1.2.9 (8.3)

DB2 Target Level: v9.5
CMOD Target Level: v8.4.1

AIX: 5.3

Thanks in advance,
Sandeep Veldi 

[Justin Derrick]

Hi Sandeep.

In short, no.

While you can have multiple versions of DB2 installed at the same time (/opt/IBM/db2/v8 and /opt/IBM/db2/v9) CMOD doesn't support this by default.  Additionally, different versions of DB2 require their own databases, as there are modifications to the database format between versions.  A similar problem exists for CMOD if you're using substantially different versions where changes were made to the system log or CMOD's internal tables.

There's also a drastically increased potential for human error -- if the wrong command is run on the wrong version of CMOD against the wrong DB2 instance, you can mangle the database or cache filesystems associated with it.

Your best bet is to use virtual machines (CMOD on Linux running in a VM on a PC) or Logical Partitions (LPARs on AIX).

-JD.

[sandeepveldi]

Thanks Justin! This is what I'm looking for.

[isig007]

Hi Sandeep.

In short, no.

While you can have multiple versions of DB2 installed at the same time (/opt/IBM/db2/v8 and /opt/IBM/db2/v9) CMOD doesn't support this by default.  Additionally, different versions of DB2 require their own databases, as there are modifications to the database format between versions.  A similar problem exists for CMOD if you're using substantially different versions where changes were made to the system log or CMOD's internal tables.

There's also a drastically increased potential for human error -- if the wrong command is run on the wrong version of CMOD against the wrong DB2 instance, you can mangle the database or cache filesystems associated with it.

Your best bet is to use virtual machines (CMOD on Linux running in a VM on a PC) or Logical Partitions (LPARs on AIX).

-JD.

[Justin Derrick]

John was interested in having me elaborate about running CMOD inside virtual machines because IBM says they don't support them.

There are still advantages to be gained from running your development, test, quality assurance, or user acceptance testing regions inside virtual machines.  I personally run CMOD on Linux inside VMs (on my Mac!) for testing -- or particularly when I'm extracting data from other CMOD servers.

For the record, running CMOD inside IBM's Logical Partitions (LPARs) *is* supported -- so it might have less to do with virtualization technology, but WHOSE virtualization technology you're using.   

-JD.