Difference colleclt vs sar
At the highest level, both collectl and sar provide lightweight collection of device performance information. However, when used in a diagnostic mode sar falls short on a number of points, though admittedly some could be addressed by wrapping it with scripts that reformat the data:
- sar plays back data by device/subsystem, sorted by time
- sar does not deal with sub-second time
- sar output cannot be directly fed into a plotting tool
- sar does not provide nfs, lustre or interconnect statistics
- sar does not provide for the collection of slab data
- sar's process monitoring is limited in that if cannot save process data in a file, cannot monitor threads, cannot select processes to monitor other than ALL or by pid (so cannot selectively discover new processes) and in interactive mode is limited to 256 processes