On Tue, Sep 10, 2019 at 5:48 PM Andreas Dilger <[email protected]> wrote: > > I don't think "lfs find -xdev" has never been a priority for Lustre, since it > is rare for Lustre filesystems to be > mounted in a nested manner. Since people already run multiple "lfs find" > tasks in parallel on different > clients to get better performance, it isn't hard to run separate tasks from > the top-level mountpoint of > different filesystems. What is the use case for this?
doesn't xdev keep find from crossing mount points, not necessarily only in a nested manner but also if there's a link to a directory in a different filesystem. i believe 'find' without -xdev will follow and descend. but this predicates that my understanding is sound (which it probably isn't). i generally add -xdev to my finds as a habit to keep from scanning nfs volumes. > along the same vein, can anyone state whether there's any actual > performance gain walking the filesystem using find vs lfs find? > > For "find" vs. "lfs find" performance, this depends heavily on what the > search parameters are. If just > the filename, they will be the same. If it includes some MDT-specific > attributes (e.g. uid, gid) then > "lfs find" can be significantly faster (e.g 3-5x0. If it is uses file size, > then they will be about the same > unless there are other MDT-only parameters, or once LSOM support is landed > (hopefully 2.13). okay, that's what i thought or recalled correctly from hearing somewhere else. in my particular instance i was just using 'find -type f' and didn't see any appreciable difference in scanning speed between the two _______________________________________________ lustre-discuss mailing list [email protected] http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
