Non-paged dynamic memory

[Volker Halle]

Wim,

it may not be trivial to find the underlying problem, but let's start like this:

SDA> SET OUT x.x
SDA> SHOW POOL/NONP/HEADER/TYPE=UNKNOWN
SDA> EXIT

$ EDIT/READ x.x

Go to the bottom of the file and look at the headers (first 4 longwords) of those unknown packets. Looking at the bottom of the file is based on the assumption, that 'something happened' and then some code started allocating those packets in some kind of loop. Can you spot any particular pattern (size, header contents) ?

Another possibilty would be to show all packets from non-paged pool (without /TYPE=UNKNOWN) to a file and apply the same kind of 'looking around'. You may see a repeating pattern of packet types filling up pool.

Consider to compare pool usage (packet types) with the running system to determine, if the high percentage of Unknown packets is the real problem.

If you've spotted some patterns, consider to include part of the SDA output in an attachment, but not a full pool listing ;-)

Volker.

[Wim Van den Wyngaert]

The output of the first command seems to contain some Sybase server related info.
But why/what ? I'll post the output.

Wim

[Volker Halle]

Wim,

the summary of your SDA> SHOW POOL/NONP/TYPE=UNKOWN output seems to indicate Unknown packets only consuming 7.4 from 55 million bytes of nonpaged pool.

Does CLUE MEM/STAT show expansion/allocation failures ?

Could you post SHOW POOL/NONP/SUMM ?

Don't expect a fast resolution (at least not with no access to the dump).

Volker.

[Wim Van den Wyngaert]

Volker,

I was confused. I saw 52% and I thought it was 52% of the whole NP dyn mem. I checked on the running system and it also takes about 50% unknown.

I also posted the output of show mem, the prove that the memory was gone.

VPA also proved that it was gone since the moment VPA started during boot.

Wim

[Volker Halle]

Wim,

your attachment looks like an SEA errlog analysis. Could you please post the SDA> SHOW MEM/POOL/SUMM output ?

If you're running VPA, you could tell, when the problem started. Did pool decrease slowly over time or did it just decrease suddenly ?

Volker.

[Wim Van den Wyngaert]

Sorry Volker.

VPA didn't see a decrease. When it started less than 1 MB was free.

Wim

[Volker Halle]

Wim,

correction:

SDA> SHOW POOL/NONP/SUMM

About some of the Unknown packets:

TCPIP does not use a standard OpenVMS packet header, but you can identify the TCPIP packets, which show up as Unknown:

If the pool packet size and the 4th longword of the packet header (count from right to left) have the SAME value and the VMS packet size word (low word in 3rd longword) is ZERO, it's most probably a TCPIP packet.

Volker.

[Volker Halle]

Wim,

let's try to re-assess the problem description:

- are we talking about unexplained static nonpaged pool consumption on 2 of your 60 Alphastations ?
- if so, is it still ORBs, UCBs, and MISCs ?

- by the time VPA starts during startup, most of nonpaged pool is already consumed.

- and today one of those 2 stations hung and you forced a crash.

Anything else ?

Could you please attach the SDA> SHOW POOL/NONP/SUMM output ?

Volker.

[Wim Van den Wyngaert]

Volker,

This is not the same problem. This time it concerns a GS160 node of an interbuilding FDDI cluster. I found it in hang and forced a crash. And after 2 minutes of boot, the memory seems to be gone.

Sorry for the mistakes but I have to use different tools to get it on my pc.

Wim

[Wim Van den Wyngaert]

Now HP nailed me ...