Showing memory utilisation
To find out the amount of physical memory:
dmidecode -t 17 | grep "Size.*MB"
To check memory utilisation:
free -m
This will show the real memory utilsation for a Linux server (i.e. without the disk cache). Look at the +/- buffers line
To check the amount of memory each process is using:
ps -e -o pid,vsz,comm= | sort -n -k 2
Checking swap utilisation
In the event of swap reservation bottlenecks, problems can be investigated as follows:
To check the current size and usage
grep SwapTotal /proc/meminfo
vmstat can be used to check current swapping, e.g.
vmstat 5 20
The si and so fields sjow swap in and swap out. If these are continuously high, especially so , you probably needto add more memory.
For historic stats you can check sar. Check /var/log/sa for the file relevant for the date you're investigating and then check the paging stats for that file, e.g.
sar -W -f /var/log/sa/sa31 12:00:01 AM pswpin/s pswpout/s 12:10:02 AM 33.34 576.34 12:20:01 AM 59.79 265.59 12:30:02 AM 133.72 46.29 12:40:01 AM 145.71 79.22 .....
Recent Changes
Contribute to this wiki
Why not help others by sharing your knowledge? Contribute something to this wiki and
join out hall of fame!
Contact us for a user name and password