Domino and Disk Fragmentation
Domino is by nature an I/O intensive application. While R8 drastically improved I/O it is still a lot of writing going on. A lot of Domino servers run on Windows and use NTFS as file system. NTFS isn't exactly designed to run large ever (size) changing files (this is why a RDBMS usually pre allocates the table space to be used - and it is done on new machines). Now just imagine that you would need to ask your admin to pre allocate your 2GB mail file quota for every user (your disk sales guy would send you to heaven for that) regardless of current need. So an NSF reflects the actual size. It's kind being in-between a rock and a hard place. Enter performance improvement strategies. An old myth is that compact -C will improve performance. While it makes the NSF neat and tidy it splatters the file segments all over the place. Adam Osborn explains it nicely in an blog entry. There is a video about it. So what should you do:
- Learn! Know the Domino Server Performance Troubleshooting Cookbook inside out. Watch Andrew's presentation on Domino performance. Ask Auntie Google
- Move your temporary filed onto another disk (I would love to hear how that works if you use a RAM disk or a solid state disk). It has 2 effects: I/O is better distributed and the temporary files don't contribute to the data disk's fragmentation. You need to set two notes.ini parameter: NOTES_TEMPDIR and View_Rebuild_Dir
- Build a high performance Domino Server (remember RAID10 looks good) and tune it well
- If Windows is your server operating system: defrag, defrag, defrag! There is an excellent presentation (don't mind the fonts) by Albert Buendia of the Spanish Lotus User Group SLUG about it. Realistically you have two choices. The free (and "find-you-own-support") DominoDefrag on OpenNTF (managed by Andrew Luder, Australia) and the commercial DefragNSF from the Australian IBM Business Partner Preemptive Consulting (run by Adam Osborne, Australia) Defrag.exe on Windows isn't an option for executing (only analysing) on your 24x7 box.