In addition to Richard Sims' consistently excellent and insightful response, one should also ensure that the microcode/firmware levels are up to date - but "if it ain't broke, don't fix it" also applies, as well.
We have noticed significant behavioral differences between microcode/firmware levels and have experienced (and resolved) problems like you mention with microcode/firmware updates. We have had several media appear to become completely unreadable (in 4-5 independent attempts on different drives) but which, following a firmware/microcode update, exhibited no subsequent problem. We have also experienced extreme performance degradation (dropping to KB/sec rates) when a brand new 3592 drive (a maintenance replacement) had to be immediately replaced (again) - and this problem was never explained. -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of Thomas Denier Sent: Friday, July 28, 2006 4:15 PM To: ADSM-L@VM.MARIST.EDU Subject: 3592 tape read performance We are seeing increasingly frequent problems reading data from 3592 tapes. TSM sometimes spends as much as a couple of hours reading a single file with a size of a few hundred megabyes. In some cases, TSM reports a hardware or media error at the end of that time. In other cases TSM eventually reads the file successfully. In the latter case there are, as far as we can tell, no error indications at all: no TSM messages, nothing logged by the OS, and no indicators on the front panel of the tape drive. In some case the same tape volume suffers this type of problem repeatedly. The problems seem to spread roughly evenly over our whole population of 3592 drives. We have just removed one 3592 volume from service because of recurrent read problems, and are about to remove a second volume from service. We only have about 120 3592 volumes, and losing two of them within a week is disturbing, to put it mildly. The possiblity that the volumes with non-recurring (so far) problems will eventually need replacement is even more disturbing. Our TSM server is at 5.2.6.0, running under mainframe Linux. The 3592 tapes drives are all the J1A model. Does anyone have any suggestions for getting to the bottom of this?
