= Resource Limits =

Blinkenshell has some limits on process and memory usage to make sure a single user does not bring down the entire machine. Some limits are higher on [[Info/Supporter|supporter]] accounts.

||'''Type'''||'''Free account limit'''||'''Supporter account limit'''||
||Memory usage (RSS)||128 MB||256 MB||
||Number of open files||128||128||
||Number of processes||100||100||
||SSH sessions||6||6||
||Background processes||2 ||5 ||

== Memory limit ==

The memory limit is based on [[Howto/ProcessManagement#Memory_usage|Resident Set Size (RSS)]] memory by using Linux cgroups feature. A free account can use 128 MB of RSS memory and a few MB swap. It's not a good idea to use 100% of the limit, for the same reason as you would not run your desktop computer at 100% memory usage. Keep below 80% memory usage to avoid warnings. If you get near the limit some programs will start to swap out, and everything will get very slow. If you hit the hard limit some of your processess will be killed according to the Linux OOM killer score. 

You can show your current memory usage with the command `showmem`

== Background processes ==

Blinkenshell counts an end-user application like a background process, for example irssi or an email client. Helper utilities like screen, tmux, sshd or bash does not count towards to limit on background processes. For example, it's ok to run a screen with one irssi instance and one alpine instance on a free account.

== Links ==
 * [[Info/DiskQuota]]
 * http://www.mjmwired.net/kernel/Documentation/cgroups/memory.txt
 * http://linux-mm.org/OOM_Killer
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