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Diffstat (limited to 'doc/bugs/git-annex_doesn__39__t_work_on_lustre__58___waitToSetLock__58___unsupported_operation___40__Function_not_implemented__41__/comment_13_5a1191042b32a85b4299cff3004d29de._comment')
| -rw-r--r-- | doc/bugs/git-annex_doesn__39__t_work_on_lustre__58___waitToSetLock__58___unsupported_operation___40__Function_not_implemented__41__/comment_13_5a1191042b32a85b4299cff3004d29de._comment | 41 |
1 files changed, 0 insertions, 41 deletions
diff --git a/doc/bugs/git-annex_doesn__39__t_work_on_lustre__58___waitToSetLock__58___unsupported_operation___40__Function_not_implemented__41__/comment_13_5a1191042b32a85b4299cff3004d29de._comment b/doc/bugs/git-annex_doesn__39__t_work_on_lustre__58___waitToSetLock__58___unsupported_operation___40__Function_not_implemented__41__/comment_13_5a1191042b32a85b4299cff3004d29de._comment deleted file mode 100644 index ae9691cf9..000000000 --- a/doc/bugs/git-annex_doesn__39__t_work_on_lustre__58___waitToSetLock__58___unsupported_operation___40__Function_not_implemented__41__/comment_13_5a1191042b32a85b4299cff3004d29de._comment +++ /dev/null @@ -1,41 +0,0 @@ -[[!comment format=mdwn - username="joey" - subject="""comment 13""" - date="2015-11-13T18:23:37Z" - content=""" -While testing a git-annex that used pid locks, on the Lustre -system I've been given access to, I observed something most -strange: - - link(".git/annex/locktmp12011", ".git/annex/pidlock") = 0 - lstat64(".git/annex/locktmp12011", {st_mode=S_IFREG|0444, st_size=70, ...}) = 0 - lstat64(".git/annex/pidlock", {st_mode=S_IFREG|0444, st_size=70, ...}) = 0 - ... - unlink(".git/annex/pidlock") = 0 - -Seeing that strace, it would make sense that the pidlock file didn't exist, -since a hard link was successfully made by that name, and link() never, -ever overwrites an existing file. The stats of the 2 files are of course -identical since they're hard links. And, since the pidlock is unlinked at -the end, we'd expect the file to be gone then. - -But, none of that has anything to do with the reality. Which was: -The pidlock file already existed, with size=72, and had existed for some -hours at the point the strace begins. The link didn't replace it -at all, and the unlink didn't delete it. When the program exited, -the pidlock file still existed, with contents unaltered. - -All I can guess is happening is that different processes on a Lustre -filesystem, running on the same host, somehow see inconsistent realities. - -I do think that, despite this being completely insane, the locking will -actually work ok, when all git-annex processes in a given repo on Lustre -are running *on the same computer*. That because git-annex actually will -drop a proper lock into a proper filesystem (/dev/shm), and so avoid all -this Lustre nonsense. - -But in general, I can make no warantee express or implied as to the -suitability of Lustre as a platform to use git-annex. If it's this -inconsistent, and modifications made to files are somehow silently rolled -back, anything could happen. -"""]] |