[gpfsug-discuss] LTFS/EE - fixing bad tapes..

[Jonathan Buzzard]

On 19/08/17 16:45, Marc A Kaplan wrote:
> I'm kinda curious... I've noticed a few message on this subject -- so I 
> went to the doc....
> 
> The doc seems to indicate there are some circumstances where removing 
> the tape with the appropriate command and options and then adding it 
> back will result in the files on the tape becoming available again... 
>   But, of course, tapes are not 100% (nothing is), so no guarantee.   
> Perhaps  the rigamarole of removing and adding back is compensating for 
> software glitch (bug!)  -- Logically seems it shouldn't be necessary -- 
> either the tape is readable or not -- the system should be able to do 
> retries and error correction without removing --  but worth a shot.
> 
> (I'm a gpfs guy, but not an LTFS/EE/tape guy)
> 

Well with a TSM based HSM there are all sorts of reasons for a tape 
being marked "offline". Usually it's because there has been some sort of 
problem with the tape library in my experience. Say there is a problem 
with the gripper and the library is unable to get the tape, it will mark 
it as unavailable.

Of course issues with reading data from the tape would be another 
reasons. Typically beyond a number of errors TSM would mark the tape as 
bad, which is why you always have a copy pool.


JAB.

-- 
Jonathan A. Buzzard                 Email: jonathan (at) buzzard.me.uk
Fife, United Kingdom.