dem@uwslh.UUCP (02/16/87)
I need some help/ideas about the cause of series of crashes. We are running 4.3 BSD unix on a VAX-11/750 with 8 M of memory. Recently, in an attempt to make better use of memory I modified several constants in the kernel. These are: CBLOCK set to 256 - The size of a clist block. I also decreased the total number of clists since they are so much bigger. NBUF set to 366 - the number of disk cache buffers BUFPAGES set to 1024 - the number of 1024 byte disk cache buffer pages I ran config, make depend, and make vmunix. The new unix does appear to have better performance, but it crashes much too often (3 times in 2 hours the first time I tried it, but not till it had been up for 1 1/2 days and twice in a day the second time, but not till it had been up for 2 days). The crash is very strange. The system does not go through the usual panic and dump, but simply halts with the codes: 800011f3 04 and then reboots. The address is in something called Xtransflt and the code 04 means interrupt stack not valid or unable to read SCB. The first time I saw this crash I figured it was a hardware glitch, but after several of them we backed up to the previous unix and the problem went away for a week. We made a newer unix and the problem repeated. Does anyone have any idea what is going on? Is it a hardware problem (possibly brought out by the software) or have I broken something in the kernel? One other item which may be relevant: Since switching to 4.3 we occasionally see crashes with the message: tbuf par fault with codes indicating cache error. We did not see these under 4.2, however we also had our vax revised to level 7 shortly before converting to 4.3 BSD. I would appreciate any help or clues that anyone can provide. -- David E. Miran ...!{seismo,harvard,topaz,ihnp4}!uwvax!uwslh!dem Wisconsin State Hygiene Lab or uwslh!dem@rsch.wisc.edu University of Wisconsin (608) 262-0019 465 Henry Mall Madison, WI 53706