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>From: Gerry Creager N5JXS <address@hidden> >Organization: Texas A&M University -- AATLT >Keywords: 200507301254.j6UCsDjo001244 Linux file systems inode Hi Gerry, Interesting read, thanks! This was timely not only because of our discussions -- several folks who attended the second LDM workshop were also fighting Linux/RAID disk performance problems. The worst example of this kind of problem is when the LDM queue is on the same RAID as the data being written. One guy's setup was much like that on bigbird -- dual Xeon (3.6 hz), 4 GB RAM, RAID. His load averages and performance mirrored what we have been seeing on bigbird. >Found this interesting whiles trying to free up space on Bigbird last >evening. > >Tom, there is no mechanism in the current set of Linux kernels I can >find that allows modification of an inode to directly delete a directory >and all contents, although it's theoretically possible. This is one of the first things I looked into before I wrote the scourBY Tcl routines. On some OSes (like Solaris), a delete is done by simply manipulating the inode tables, so it is very fast. For some reason the Linux developers took a different approach. >'rm' even with >the -rd switch, still wants the directories empty before removal. Yup. >May be worth looking at a new utility that enables inode write/directory >removal. I agree. The real question is why this does not already exist!? One would think that all of those folks that are benchmarking performance on different file systems (ext3, riser4, xfs, jfs, etc.) would have dug into the problem and presented a solution by now. >http://kerneltrap.org/node/715 Cheers, Tom -- +-----------------------------------------------------------------------------+ * Tom Yoksas UCAR Unidata Program * * (303) 497-8642 (last resort) P.O. Box 3000 * * address@hidden Boulder, CO 80307 * * Unidata WWW Service http://www.unidata.ucar.edu/* +-----------------------------------------------------------------------------+