Hi all,

I have 2 servers, both running "Red Hat Linux Advanced Server release 2.1AS (Pensacola)" on identical hardware (DELL PowerEdge 4600 servers).

Both have the latest version of 7zip running. (p7zip_4.45)

One runs 7zip commands no problem. The other hangs on files that are roughly 1Mb or larger.

It starts to process the file - then just sits there until I force an interrupt......
7za e file.7z

7-Zip (A) 4.45 beta Copyright (c) 1999-2007 Igor Pavlov 2007-04-17
p7zip Version 4.45 (locale=en_US,Utf16=on,HugeFiles=on,4 CPUs)

Processing archive: file.7z



sits here until interrupt sent

One difference with the servers is the one that has no problem with 7zip has Oracle running and has had memory adjustments. Maybe the difference is responsible for the success vs failure.

What I would like to know is, based on the below memory settings, what command I need to run to temporarily adjust max seg size and test 7zip.

I am assuming I can change the setting, test it, and change it back if I want to. Also, if I make the change permanent, do I change /etc/sysctl.conf?? - what is the exact command?

The memory settings on the server with no problem running 7zip...
ipcs -lm

------ Shared Memory Limits --------
max number of segments = 4096
max seg size (kbytes) = 1048576
max total shared memory (kbytes) = 8388608
min seg size (bytes) = 1

...and on the problem server...
ipcs -lm

------ Shared Memory Limits --------
max number of segments = 4096
max seg size (kbytes) = 32768
max total shared memory (kbytes) = 8388608
min seg size (bytes) = 1

If you think there is another solution, please do post it.

Thanks.

To change the “maximum shared memory segment size”, you’d do something like:
(where blah is the desired number)

You also might want to try a debugger to see where the problem occurs.

Thanks osor. I tried adjusting the memory settings to no avail.

I guess I need to debug. Any suggestions on a debugger to use? I have not yet had a need to get into debugging. I am fairly new to linux and still finding my feet.

It is interesting to me that at times, when interrupted, "Everything is okay" will be displayed, other times it just returns straight to prompt. Archive still in tact (not extracted) As far as I know, the only difference with the two servers is that memory setting.

It also takes two interrupts to respond (ctrl + c)

I would use gdb (though it may be daunting at first). For best results, you will need to compile p7zip with debugging symbols (or find a precompiled debugging version). If you just want to see if the application is hanging on a specific system call, strace might be the tool to use.