On Wed, 11 Jul 2007, Ofer Inbar wrote:
> gmetad is very write-intensive, because it updates hundreds of RRD
> files about every minute or two. Has anyone tried running it with
> the rrd directory on a RAM disk (tmpfs) ?
>
> You'd need something to periodically copy the RRDs to a real disk,
> but that could happen much less frequently (maybe every 20 minutes).
>
> You'd also need a more complicated boot time startup procedure to set
> up the repository on RAM disk before starting gmetad.
>
> Have any of you tried anything like this? What'd you do? How'd it go?
> -- Cos
First of, you need to reroute your data, e.g. to /dev/shm. So in
gmetad.conf I have the following:
...
#-------------------------------------------------------------------------------
# Where gmetad stores its round-robin databases
# default: "/var/lib/ganglia/rrds"
# rrd_rootdir "/some/other/place"
rrd_rootdir "/dev/shm/rrds"
Secondly, in /etc/init.d/gmetad you need to create /dev/shm/rrds before
using it. So I have this:
## if rrd directory in /dev/shm does not exist, create it
if [ -d /dev/shm/rrds ] ; then
echo "rrd directory already exists in /dev/shm"
else
mkdir /dev/shm/rrds
chmod 755 /dev/shm/rrds
chown nobody.nobody /dev/shm/rrds
fi
Thirdly, you need some logic to archive the rrds from /dev/shm/ to a
disk.
Hope that helps,
Matthias
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by DB2 Express
> Download DB2 Express C - the FREE version of DB2 express and take
> control of your XML. No limits. Just data. Click to get it now.
> http://sourceforge.net/powerbar/db2/
> _______________________________________________
> Ganglia-general mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/ganglia-general
>
-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
Ganglia-general mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/ganglia-general
