At various places, one could & still can find the advice that the TSM B/A client
for UNIX (and in particular LINUX) will backup "unsupported" file system types,
once you add to "dsm.sys" a VIRTUALMOUNTPOINT entry mentioning the actual mount 
point.

Sufficiently old "dsm.sys" on LINUX may even contain (meanwhile redundant)
VIRTUALMOUNTPOINT entries for all file systems, because the very first
(V3) LINUX B/A client would (if I remember correctly) support nothing but EXT2,
which was just one of many file system types in use, even back then.

Now for the risk: Without VIRTUALMOUNTPOINT, when a file system goes offline,
the TSM backup client will notice, possibly give an error indication (only if
that file space was explicitly mentioned as a DOMAIN), and in particular
not process the corresponding file space, i.e. not mark its files as "gone".
With VIRTUALMOUNTPOINT mentioning the mount point, however, once nothing is 
mounted,
TSM takes the (normally empty) "mount point" directory for the root of the file 
space,
so it does not indicate an error during backup, but will duly inactivate all 
files
of that "virtual" file space ...

Beware!


Best regards,

        Wolfgang J. Moeller <moeller AT gwdg DOT de>

Tel. +49 551 201-1516 ... not representing ... GWDG, Goettingen, Germany