I've been running some tests on files created by rsync and noticing big fragmentation issues. I started the testing because our 5TB array started performing very slowly and it appears fragmentation was the culprit. The test I conducted was straighforward:
1. Copy over a 49GB file. Analyzed with contig (from sysinternals), no fragments.
2. Ran rsync and the file was recreated normally (rsync options were -ruvi --times --no-blocking-io --compress-level=9 --bwlimit=0 --stats --delete --modify-window=2)
3. Resulting file had almost 12000 fragments.
It doesn't really surprise me since rsync grabs blocks as it needs them for the new file. I was wondering why rsync doesn't preallocate the space like copy or other utilites do. This would insure you have the space to create the new file.
Just wondering...any suggestions? By the way, your site has been a huge help, thanks for the work!