In my experience, x-2 (two previous versions) is always supported -- anything more than that is a gamble.
So, 9.5 to 10.1 is X-2 (10.1 -> 9.7 -> 9.5) and should definitely be supported.
But what liakkuan wants to do is x-4 -- 9.1 ->10.5, skipping over 9.5 and 9.7 and 10.1...
It might be possible to upgrade v9.1 to a fixpack level that's functionally equivalent to v9.5 -- which is closer to what you want... But I would imagine it's unsupported and undocumented.
Like I said, if liakkuan wants to change server, then the most "easy" way to do it is:
a) install the new DB2 version 10.5 latest fix pack
b) create an db2 instance
c) create a database with exactly the same codepage/territory as the original DB
d) export all the CMOD tables from the original DB with db2move export
e) get all the structure of the original db with db2look
f) apply the structure from point e) to the new DB (you might need to modify some things, like the path, etc... from the output of db2look)
g) load all the tables to the new DB with the command "db2move load"
and you can really go from DB2 V8.X to V10 without any problems.
Of course, if you want to install the old version in the new server, restore the whole database with the old version, then do the official upgrade on the instance, then yes, you might need to do some middle upgrade in between...
I've never done that, since I want to keep it simple :-)
Now YMMV... but in any cases, this needs to be tested tested tested, with any method, the "normal" db2 upgrade, or the db2move method.
BTW, I've done once a migration from CMOD DB2 on Windows, to a CMOD using Linux... and this method was the only one that was working. And now 3-4 years, it is still running, and I have performed an upgrade from V8.5 to V9.5 without a single problem.