Minimize mounts for dual copy tape pool recalls
I selected 603 on tape I56774
and recalled all these files.
To my surprise, several tapes were mounted:
[root@eosctafst0105 ~]# cta-admin sq
type tapepool logical library vid files queued data queued oldest age priority min age max drives cur. mounts cur. files cur. data MB/s next mounts tapes capacity files on tapes data on tapes full tapes empty tapes disabled tapes rdonly tapes writable tapes
Retrieve r_harp_2 IBM1L8 L74721 32 25.8G 6966 1 300 30 0 0 0 0 0 9.0T 19399 9.3T 0 0 0 0 1
Retrieve r_harp_2 IBM1L8 L75863 9 8.9G 6966 1 300 30 0 0 0 0 0 9.0T 16629 7.1T 0 0 0 0 1
Retrieve r_harp_2 IBM1L8 L74634 13 15.8G 6966 1 300 30 0 0 0 0 0 9.0T 116978 10.9T 1 0 0 0 0
Retrieve r_harp_2 IBM1L8 L75608 4 6.9G 6963 1 300 30 0 0 0 0 0 9.0T 34570 11.7T 1 0 0 0 0
Retrieve r_harp_1 IBM355 I56774 0 0 0 0 0 0 1 0 0 0 0 15.0T 96781 21.2T 1 0 0 0 0
Retrieve r_harp_2 IBM1L8 L75046 0 0 0 0 0 0 1 0 0 0 0 9.0T 39988 12.5T 1 0 0 0 0
While I56774
contained all the files I wanted to recall in the first place: this is how I selected these.
What happened is that these files have 2 copies on different tapes and some were queued on r_harp_2
and others on r_harp_1
and this resulted in 6x the mount of mounts.
Something should be done to minimize tape mounts or at least keep them under tighter control and deterministic.
Here recalls are sometimes on r_harp_1
and sometimes on r_harp_2
?
How is the pool chosen?