SEYMOUR@phast.PHYS.WASHINGTON.EDU (12/24/87)
There was a question about putting vms sysdump.dmp somewhere useful, instead of occupying lots of otherwise lost disk space. Dear ol' dec provides it: (this is a RTFM answer) (ref: vol 10a, system dump analyzer ref manual, sect 2.2) Use sysgen to set SAVEDUMP to 1 (non zero). That tells the system to do the dump into the pagefile instead of into sysdump.dmp. Upon rebooting, that setting will take effect. The pagefile will receive all of your memory, plus 4 pages. (the original question mentioned a dump file equal to the memory size... it MUST be 4 blocks bigger, or it's useless) Upon your next crash (does vms crash?) your pagefile will come up with those pages occupied, so it had better be big enough to hold all of that and still boot and run through your startup files. You release the space by invoking ANALYZE/crash sys$system:pagefile.sys and then telling ANALYZE to COPY destination_file that will copy the dump to a (non contiguous) file and free the pagefile pages. You can look at the dump with analyze before copying it. The pagefile pages are not released for normal use until the copy is done. If you just want to throw away the dump, you can copy to the NL: device. SHOW MEMORY shows the pagefile usage. DEC recommends that you make the COPY part of your sys$manager:systartup.com file. DEC also recommends that your pagefile be at least 1000 (1k) blocks larger than the required dumpfile size. CMKRNL privlege is required to free-up the pagefile, but not for the copy operation. i do it. It works. It's wonderful for rd53 systems. dick seymour, bitnet: seymour@uwaphast (univ of washington)
jeh@crash.cts.com (Jamie Hanrahan) (12/26/87)
In article <UWAVM.ACS.WASHINGTON.EDU:LB@EPmLD*> SEYMOUR@phast.PHYS.WASHINGTON.EDU writes: >Use sysgen to set SAVEDUMP to 1 (non zero). >That tells the system to do the dump into the pagefile >instead of into sysdump.dmp. Ahh, not quite. The absence of the file SYS$SYSTEM:SYSDUMP.DMP tells the system to do the dump into the pagefile. Setting SAVEDUMP to 1 tells the system to not make the blocks so used available for paging until you use the SDA COPY command on the pagefile. [An aside: I wish folks would leave the Subject: line alone when posting followups. I just posted a reply to the same original article after doing a ^N in rn and seeing no definitive answers already extant. Of course, in this case, I'd have still posted my reply after seeing the above-quoted article, as the above-quoted article isn't quite right, nor is it complete; but at least I'd have been able to post one reply instead of two.] >I do it. It works. It's wonderful for rd53 systems. You got that right! (It was originally invented for MicroVAX 0.5's... er, VAX 730's, some of which were crippled, er, sold with just two RL02's (10 MB each) for disk storage...)