Ric Wheeler wrote:
Every level of the the system tries to guess how to combine and read ahead, all the way from the file system down to the internal firmware in the storage.
I remember Kirk McKusick once complaining about how hard it was to write a file system when so many other levels in a system try to second guess what he was trying to do. I've also heard disk engineers complain about the same thing, except they complain about the OS people not leaving optimization techniques to them. Go figure.
I think that fragmentation is a bad performance hit, but that we actually do relatively well in keeping our files contiguous in normal cases.
We might disagree on how bad the performance hit is, but I'm really trying to prevent non-technical people from panicking when they see a fragmented filesystem (or file).
I have a simple bit of c code that uses fibmap to dump the sectors/blocks for a specific file. If you like, I can send it over to you.
Sure. Thanks. -- Jon Forrest Research Computing Support College of Chemistry 173 Tan Hall University of California Berkeley Berkeley, CA 94720-1460 510-643-1032 jlforrest@xxxxxxxxxxxx _______________________________________________ Ext3-users mailing list Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users
