On Thu, Jun 02, 2005 at 05:34:44PM -0400, Dan B. Phung wrote: > What is the current locking granularity of GFS? I found an IBM GPFS > report that stated the GFS uses a global lock, which is entirely false > since I know GFS uses DLM. > > From what I've seen from use, my guess is that it's at the directory > level, which seems wierd. Writing to different files in the same > directory gives sequential finishing times. when I modified the output to > go to different directories, this change alleviated the finishing times > disparity. GFS has a couple pf locks for each file. (one for data, one for meta data, one for iopen counts. maybe others, don't recall off the top of my head.) Directories get a lock, as well as most of the interal structures. So more-or-less gfs locks at the file level. (note that this is not the same or similar to fcntl locking, nor is it compatible.) -- Michael Conrad Tadpol Tilstra I can read your mind, and you should be ashamed of yourself.
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