Why does the sort data collector rely on swap space to be available?
The sort data collector is dependent on the fact that swap is configured on our systems.
"The system on which you install the data collector must meet the
following minimum requirements:
* 500 MB free RAM
* 300 MB free swap space
* 2 GB free disk space"
If no swap is configured the data collector exits with the statement that swap is required.
Most of our systems have 256 GB of memory and we mainly run databases on our systems. When the system starts to swap we
get a lot of complaints about the bad performance. As a consequence we debate from time to time if we should disable swap or not. And on some systems where we disabled swap it brought us some improvements.
To check for swap space might be a valid check for systems with a low memory footprint, but on systems with a high memory footprint I don't see the necessity (this is at least my opinion).
In my opinion sortdc should be easy to use.
Would it not be possible to adjust sortdc to check for 800 MB (500 MB + 300 MB for swap) of free memory when no swap is configured.
A support case was opened with the Symantec (05096990) and the outcome was, that I got told that this will not change.
Maybe worth reading as well the following article: http://linux-mm.org/Low_On_Memory.
Don't get me wrong - there are workaround solutions in place to overcome this, but sort should be clever enough to just not exit when we still have GBs worth of memory free and no swap configured.