Drives become unavailable

[Mohsin Saleem Khan]

Hi,

         We have two drives define in TSM 5.1 Level 6.5, it has been
happening now from few days that every drives become unavailable quite
often, and I update them as online=yes they become available again....I am
not sure why it is happening and what should i do, to get stable drives,
any help

Regards
Mohsin