On 23 February 2012 13:52, Bruce Richardson <[email protected]> wrote: > Hello IBM-MAIN people,
Hi Bruce - long time, etc... > One of our difficult processes is the JES2 OFFLOAD. Every weekday night > (at 18:30) we start the offload of production output to tape (with PURGE). > Before the new tape library, this would take less than a full 3490 cartridge > (and it still takes less than a full 3590 cartridge - a very small fraction > of a cartridge and a lot of waste). From my reading of the JES2 commands, it > seems that JES2 OFFLOAD can not deal with file sequence numbers (more than > one file per tape). I have no experience with this in current JES2 versions, but I wonder if you could use catalogued tape datasets. The JES2 doc is not terribly clear, but it does say that it supports catalogued datasets on DASD and tape, and certainly the catalogue entry for a dataset on tape includes the file sequence number. > One of the questions I have is, can JES2 append to an existing OFFLOAD > tape? I would like to be able to mount the same tape for month (roughly 20 > working days). I know that as job numbers roll over 9999 to 1 I might get > into the slim possiblity of JOBNUM/JOBNAME conflicts on restoring the output. There are two kinds of appending one might contemplate: adding data to an existing dataset on the tape, and adding a new dataset to the tape as a separate file. The former would have to be explicitly supported by JES2, and I'm sure it does no such thing at the moment. The latter is what would result from using my catalogued tape dataset suggestion, if it works at all. There would be multiple, unrelated offload datasets that just happen to be on the same physical volume. Presumably you would have to invent a naming scheme so that you would unload to (and potentially reload from) the right places. I also gather that JES2 supports a max of only 8 offload devices, but it looks as though you can dynamically change the dsname, so perhaps you could stick with one device and update the name for each day. Something I'm not clear on is whether you routinely reload this data, or of it's just for backup. Any scheme that involves appending to tape has higher risk and to more data than one that writes to a unique tape for each day (or other unit of work). Regardless, it sounds easy to experiment with. Tony H. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
