I looked up both the reason codes 00C900A5 and 00C90084. The DB2 messages and codes guide said "Explanation: The temporary file with the page size shown in NAME is not available. An error was detected either during the opening of the page set or during the formatting of the header and the space map pages of the pageset.
If the reason code appears in a DSNT500I message issued during the -START DATABASE command, the request fails. In either case, the temporary file function does not allocate any temporary file on the page set."
I checked the 4K datasets DB2CAT.DSNDBC.DSNDB07.DSN4Kxx.I0001.A001. We've 6 of them. I checked the extents on these, and they had spanned for only one extent. So the problem must be something else. I decided to stop and start the 4K tablespaces and issued a STOP against these 6 tablespaces. However, they were in STOPP (Stop Pending) status for a long time. That's when I looked in Omegamon for DB2 and found that there were 4 threads that we running for a long time and had consumed millions of getpages, they were sorting large amounts of data, which means they were using up most of the 4K space. I killed these 4 threads and voila, all the 6 tablespaces stopped. I then issued the START command and started them. They came up without any hiccup and all the error messages stopped.
