Everyone thanks so much for confirming what I was told. Where my problem arises is when a user wants to recall 5000 or more datasets. I was concerned that the recall process would serialize it rather than finding all the files on a given migration tape and work with it until it needed a new tape.
Very helpful Lizette > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf > Of O'Brien, David W. (NIH/CIT) [C] > > Hervey, > > That is not true, at least not at this shop. HSM routinely queues recalls according to > tape volume in order to minimize tape mounts with or without CRQ. > > Dave O'Brien > > -----Original Message----- > From: Hervey Martinez [mailto:[email protected]] > Sent: Thursday, October 11, 2012 7:55 AM > To: [email protected] > Subject: Re: DFHSM Recalls and Tape > > If you have CRQ(Common Recall Queue) set up, then HSM will "look ahead" and recall > all files that are on the same tape. Also, with CRQ, you can limit which LPARS will > perform recalls and limit them in that manner and all recalls will be routed to that > LPAR. Otherwise, the recalls happen one at a time in a FIFO manner. > > Regards, > > Hervey > > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf > Of Robert A. Rosenberg > Sent: Thursday, October 11, 2012 3:58 AM > To: [email protected] > Subject: Re: DFHSM Recalls and Tape > > At 20:58 -0500 on 10/10/2012, Mike Schwab wrote about Re: DFHSM Recalls and > Tape: > > >When it HSM finishes a recall, it checks the que in order for any > >recall on the same tape. When it reaches the end of the que, it > >unmounts the tape, and starts recalling the first waiting dataset on > >the que. Haven't done as massive a quantity as 10,000 though. > > > >No sorting of any kind, just checking the que DSN against the list on > >the mounted tape. > > So you are saying that as it reads the tape (after it has recalled a file from the tape) it > sees the next file on the tape and checks if it is on the queue. It then either recalls the > file (if it is on the > queue) or reads the tape to the next file and does the queue check again. > > From your "no sort" comment, I assume that it does not order the queue based on > restore tape volume but just runs the full queue until it finds the dataset name or > reaches the end of the queue. If the latter it seems inefficient since if the queue was > ordered by volume serial number it could stop the scan once it reached an entry on a > different tape. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
