> > Hi list, > > I just detected a rather strange memory behaviour on (at least) one of > our redhat 7.1 machines (kernel 2.4.9-6, DELL Precision 530 2x1.7GHz). > I wonder if anybody can point me in the right direction or give me some > URL for further reading and understanding. > > The user on that machine is running a memory-expensive flow solver, and > as the 2GB RAM weren't enough ( :-) ) we upgraded to 4GB RAM about two > weeks ago. The first thing we noticed was, that the kernel mentioned > only 3.7GB instaed of 4GB, but I found on the internet that this is > sort of okay, and we could get around this by using an enterprise > kernel. We let this as an option for the future, as the flow solver > currently is happy with 3.7GB. > > In the meantime it turned out that sometimes the kernel reports a big > chunk of the memory as 'in use' (according to top/gtop at least), but I > am unable to figure out by which process this memory is used. When the > user starts one of his jobs then (consuming let's say 3GB of memory) > the machine starts swapping soon, slowing down the job significantly. > > My question now is: Is there a way to see which process (PID perhaps) > is using the memory / had allocated it? It is not visible in top/gtop, > but reported as used. Am I maybe suffering from some weakness of the > kernel and should I try a kernel upgrade? Are there any commands by > which I might get more information about whats going on? > > Thanks in advance for any hint, and kind regards, > Urte
The other big possibility for the swapping is cache/buffers used by the system. Try cat /proc/meminfo to see if linux itself is using up a lot/most of your memory. What happens is that linux will use up as much 'spare' memory as is available for cache/buffering. It will free up some when processes need it. This may be what is happening to you - but the meminfo output will tell you. Specifically 'MemFree:' will give you an idea of how much memory is available to processes without any swapping. -- -Cheers -Andrew MS ... if only he hadn't been hang gliding! _______________________________________________ Seawolf-list mailing list [EMAIL PROTECTED] https://listman.redhat.com/mailman/listinfo/seawolf-list
