Besides the details about Node’s memory footprint, it was also intersting to see how much space we gain form the rootfs by our minimization efforts.
The idea is to take a recent oVirt Node image, and compare some stats of it, to the stats of a regular image, build using the
The two points I investigated are:
- How does the minimization affect the number of packages?
- How does the minimization affect the space requirements?
- first one was addressed by counting the number of installed packages (
- the second one was addressed by
- Summing up the reported size of the installed packages (
- Determining the disk space in use (
Because guestfish’ing into a LiveCD is tiresome, I created this script to gather the stats for me. Additionally it’s nice to have a tool by hand to create reproducable results.
The results are - once again - interesting.
$ bash img-stats.sh ovirt-node-iso-scratch.iso runtime-layout.img
ImageSize: 197.00 MB
SizePkgs: 867.50 MB
SizeRootfs: 564.97 MB
ImageSize: 1543.63 MB
SizePkgs: 1071.67 MB
SizeRootfs: 1323.57 MB
What do we see here?
- We see that the plain rootfs has 41 additional packages installed. Or the other way round: 41 packages are blacklisted on the LiveCD.
- The sum of reported rpm sizes is ~200 MB higher on the plain rootfs than on the livecd
- The disk usage on the plain rootfs is ~760 MB higher than on the livecd
Especially the last two points indicate that the file based blacklisting is actually responsible for freeing up so much space.
This is just a rough estimate. More time needs to be spend on investigating the details of this differences.