We have a 110G VM LPAR. Dumps, however rarely they may be taken, do take time and space. We have 2 mod-09s specified as DUMP in SYSTEM CONFIG. Right now, 53% of one of the dump packs is allocated; the other, 0%. DUMPLOAD requires a full mod-09, as well. VMARC PACK of the dump, once loaded, gives considerably better compression than does COPYFILE. The last time that I sent a VMARC packed dump to IBM, it actually made it without error. IIRC, it has been awhile since I last sent a dump to them, it took about an hour. I have had problems FTPing big dumps to other vendors. VSSI has the ability to process partial dumps, so I have not had to break a dump into pieces for them - they usually find the problem in the first part that they receive.
The operators do get antsy about the time it takes for the system to complete a dump and restart, but they are getting used to big systems taking a long time to dump. I would say that here, the priorities are, if possible, (1) speed up the time to take the dump and (2) reduce the size of the dumps. The 2 are not mutually exclusive. Regards, Richard Schuh > -----Original Message----- > From: The IBM z/VM Operating System > [mailto:[email protected]] On Behalf Of Lee Stewart > Sent: Wednesday, November 04, 2009 11:44 AM > To: [email protected] > Subject: VM Dump Quandries > > Large systems can be a challenge... > > Problem #1 -- Dump time. Customer took an abend on a 190GB VM LPAR. > VM started dumping. (We assume it was to be a "small" dump > -- just CP areas and the frame table.) Dumping at the rate of > "25% every 6 > minutes"... (And we're dumping...) The customer IPLed at > 12 minutes > into the dump because they needed to get their production > systems back up. > > Have any of the other large LPAR shops dealt with this? > (Other than SET > DUMP OFF ;-) Telling a customer to leave his system down > for half an > hour for a dump isn't popular... > > Problem #2 -- Dump size. CP seems to allocate about 17GB for dump > space out of the spool. Then to try and process the dump I'd need > something like a mod-27 as a single large CMS minidisk... > (Or a giant > SAN LUN.) Then what? If I'm going to send the dump to IBM, I doubt > FTPing a 20GB file is a choice... Back to good old tape? > > #2a -- does IBM accept huge SPXTAPE DUMPs? > > Thoughts and suggestions (other than make the LPARs smaller) > welcome... > Lee > -- > > Lee Stewart, Senior SE > Sirius Computer Solutions > Phone: (303) 996-7122 > Email: [email protected] > Web: www.siriuscom.com >
