VAX System Dump Analyser

[Sk Noorul Hassan]

When I am giving the command, ANA/CRASH SYS$SYSTEM: the following message is displayed

"Dump File FLAGS2 DMP$V_VAXDUMP should be set"

Can anybody guide me on how to analyse the crash dump if the above message displayed.

[Karl Rohwedder]

Here is the HELP:


VAXDUMP, dump file FLAGS2 DMP$V_VAXDUMP should be set

Facility: SDA, System Dump Analyzer

Explanation: The dump file you are trying to analyze does not have the
FLAGS2 DMP$V_VAXDUMP bit set in the dump file header. Either
the dump file was created on an OpenVMS VAX system prior to
Version 7.1, or another event caused the FLAGS2 DMP$V_VAXDUMP
bit to be cleared.

User Action: None. The OpenVMS VAX System Dump Analyzer will continue to
access this dump file.

It's pretty self-explaining.

regards Kalle

[Volker Halle]

Hi,

do you get to the SDA> prompt at all ?

If not, try DUMP/BL=COUNT=2 SYS$SYSTEM:SYSDUMP.DMP and post the output as a .TXT attachment, if it's NOT all zeros.

Are you trying to analyze the dump on the SAME system, where it has happened ?

Volker.

[Volker Halle]

The DMP$M_VAXDUMP flag is written when the dumpfile header is re-written for the last time during bugcheck processing. It's written together with the WRITECOMP flag.

Did you get any other error messages from SDA ?

Volker.

[Jan van den Ende]

Hassan,

Is

ANA/CRASH SYS$SYSTEM:

the WHOLE command you used?
Then itt should be
ANA/CRASH SYS$SYSTEM:SYSDUMP.DMP

hth

Proost.

Have one on me (maybe in May in Nashua?)

jpe

[Robert Brooks_1]

Simply typing $ ANAL/CRASH SYS$SYSTEM:

is documented as valid syntax.

From HELP ANAL/CRASH . . .

filespec

Name of the crash dump file to be analyzed. The default file
specification is:

SYS$DISK:[default-dir]SYSDUMP.DMP

SYS$DISK and [default-dir] represent the disk and directory
specified in your last SET DEFAULT command. If you do not
specify filespec, SDA prompts you for it.

[amit sharma_1]

Hi nurul.. at system prompt type the following command:
$ ana/crash sys$system:sysdump.dmp

it'll analyze your latest crash dump file and you'll get "SDA>" prompt.

Amit Sharma,
CMC Ltd, India

[Arch_Muthiah]

SK,

I am wondering how this DMP$V_VAXDUMP got cleared; if no dump info written, then thers is a chance that this flags will never be set.
Otherwise I doubt your SYSDUMP.DMP file may have been copied from alpha. So v_vaxdmp will be left cleared and v_alphadump flags will be set first disk block of dump file.

Archunan

[Sk Noorul Hassan]

Hi, Sorry I was not in the office.

Yes Volker, I amm not getting the SDA prompt.Actually, immediately after system crash I am getting the SDA prompt and able to see the reason. But once I reboot the server, I am getting the error "FLAGS2 DMP$V_VAXDUMP should be set, dump file contains no valid dump". I have created fresh dump file also, but once rebooting, it is giving the same error.

Pls suggest

[Volker Halle]

That's what you get, right ?!

$ ANAL/CRASH SYS$SYSTEM:

OpenVMS (TM) VAX System dump analyzer

%SDA-W-VAXDUMP, dump file FLAGS2 DMP$V_VAXDUMP should be set
%SDA-E-DUMPEMPTY, dump file contains no valid dump
$

On OpenVMS VAX, the system dump file header is overwritten during a shutdown (unlike on OpenVMS Alpha), so you will not be able to do ANAL/CRASH SYS$SYSTEM:SYSDUMP.DMP once a subsequent shutdown has overwritten the dump file (header).

After a crash, you should immedaitely copy the dumpfile to another location using the SDA> COPY file command, using $ COPY or $ BACKUP/IGNORE=NOBACKUP.

It is possible to 're-validate' the dump file using my REVALIDATE_DUMP tool or the PATCH utility, to be able to use ANAL/CRASH after a shutdown has overwritten the dump file header. Do you need to do this for this dump ?

Volker.

[Sk Noorul Hassan]

Yes Volker, if u can please attach the tool.

[Volker Halle]

If you could provide the output of DUMP/BL=COUNT=1 SYS$SYSTEM:SYSDUMP.DMP, I can write up the necessary PATCH commands for OpenVMS VAX to patch the dump file. Please also provide the file size in blocks and the memory size from SHOW MEM.

Volker.

[Volker Halle]

Here is how to patch a FULL OpenVMS VAX system dump file (DUMPSTYLE bit 0 clear), which has been overwritten by an operator shutdown:

- get the minimum value of the dumpfile size or memory size (SHOW MEM - Main memory Size in Pages from column Total) in HEX (use as memsize-in-hex below)

- make a copy of your dumpfile (use COPY or BACKUP/IGNORE=NOBACKUP)

- $ PATCH/ABS/NONEW copy-of-your-dumpfile
PATCH>dep/by 04=0C0
old: 00000004: 080
new: 00000004: 0C0
PATCH>dep/long 7c=memsize-in-hex ! e.g. 100000
old: 0000007C: 00000000
new: 0000007C: 00100000
PATCH>exit

$ ANAL/CRASH copy-of-your-dumpfile

Volker.

[Sk Noorul Hassan]

Volker,

Sorry for the delay. Total Memory size in pages is 262144(128 MB) & Dumpfile size is 262153 in blocks.

[Volker Halle · Accepted solution]

Thanks for the info, so the patch commands are:

$ PATCH/ABS/NONEW copy-of-your-dumpfile
PATCH>dep/by 04=0C0
old: 00000004: 080
new: 00000004: 0C0
PATCH>dep/long 7c=40000
old: 0000007C: 00000000
new: 0000007C: 00040000
PATCH>exit

Note, that this will not make the %SDA-W-VAXDUMP message go away, but it should allow you to get to the SDA> prompt and analyze your crash.

Please report, whether this worked for you.

Volker.

[Sk Noorul Hassan]

Thanks Volker,

It is working properly.

Just one clarification, how you arrived at memory size in HEX as 40000. On what size it depends i.e. upon memory size or the dump file size ? Because when I did the procedures mentioned by you with same memory size(262144) but not same size dump file, it is not working.

[Volker Halle]

The value stored in the dumpfile header at offset 7C is DMP$L_MEMPAGCNT, the count of memory pages dumped.

It can't be greater than the dumpfile size. It should be the same as the physical memory size (at least for full dumps with DUMPSTYLE bit 0 = clear).

Does this clarify your question ?

Volker.