Lionel Bouton posted on Tue, 15 Dec 2015 03:38:33 +0100 as excerpted: > I just checked: this has only be made crystal-clear in the latest > man-pages version 4.03 released 10 days ago. > > The mount(8) page of Gentoo's current stable man-pages (4.02 release in > August) which is installed on my systems states for noatime: > "Do not update inode access times on this filesystem (e.g., for faster > access on the news spool to speed up news servers)."
Hmm... I hadn't synced and updated in about that time, and sure enough, while I've just synced I've not yet updated, and still have man-pages 4.02 installed. But, the mount.8(.bz2 in my case as that's the compression I'm configured for, I had to use man -d mount to debug-dump what file it was actually loading) manpage actually belongs to util-linux, according to equery belongs, while equery files man-pages | grep mount only returns hits for mount.2(.bz2 and umount). So at least here, it's util-linux providing the mount (8) manpage, not man-pages. Tho I'm on ~amd64 and IIRC just updated util-linux in the last update, so the cross-ref to nodiratime in the noatime entry (saying it isn't necessary as noatime covers it) probably came from there, or a similar recent util-linux update. Let's see... My current util-linux (with the xref in both noatime and nodiratime to the other, saying nodiratime isn't needed if noatime is used) is 2.27.1. The oldest version I still have in my binpkg cache (tho I likely have older on the backup) is util-linux 2.24.2. For noatime it has the wording you mention, don't update inode access times, but for nodiratime, it specifically mentions directory inode access times. So from util-linux 2.24.2 at least, the information was there, but you had to read between the lines a bit more, because nodiratime mentions dir inodes, and noatime says don't update atime on inodes, so it's there but you have to be a reasonably astute reader to see it. In between those two I have other versions including 2.26.2 and 2.27. Looks like 2.27 added both the "implies nodiratime" wording to the noatime entry, and the nodiratime unneeded if noatime set notation to the nodiratime entry. If there was a util-linux 2.26.x beyond x=2, I apparently never installed it, so the wording likely changed with 2.27, but may have changed with late 2.26 versions as well, if there were any beyond 2.26.2. And on gentoo, 2.26.2 appears to be the latest stable-keyworded, so that's what stable users would have. But as I said, the info is there at least as of 2.24.2, you just have to note in the nodiratime entry that it says dir inodes, while the noatime entry simply says inodes, without excluding dir inodes. So it's there, you just have to be a somewhat astute reader to note it. Anywhere else, say on-the-net recommendations for nodiratime, /should/ mention that they aren't necessary if noatime is used as well, but of course not all of them will. (Tho I'd actually find it a bit strange to see discussion of nodiratime without discussion of noatime as well, as I'd guess any discussion of just one of the two would likely be on noatime, leaving nodiratime unmentioned if they're only covering one, as it shouldn't be necessary to mention, since it's already included in noatime.) But there's probably a bunch of folks who originally read coverage of noatime, then saw nodiratime later, and thought "Oh, that's separate? Well I want that too!" and simply enabled them both, without actually checking the manpage or other documentation including on-the-net discussion. I know here I originally saw noatime and decided I wanted it, then was confused when I saw nodiratime sometime later. But I don't just enable stuff without having some idea what I'm enabling, so I did my research, and saw noatime implied nodiratime as well, so the only reason nodiratime might be needed would be if you wanted atime in general, but not on dirs. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
