From: Jan Kara Date: Wed, 13 Jan 2010 17:07:33 +0000 (+0100) Subject: mount: update documentation about barrier mount options X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=864d161e6310bfa9779e318777fdf19c3b500586;p=util-linux mount: update documentation about barrier mount options Signed-off-by: Jan Kara --- diff --git a/mount/mount.8 b/mount/mount.8 index 217071ec..2888b46d 100644 --- a/mount/mount.8 +++ b/mount/mount.8 @@ -1267,7 +1267,11 @@ in files after a crash and journal recovery. .TP .BR barrier=0 " / " barrier=1 " This enables/disables barriers. barrier=0 disables it, barrier=1 enables it. -The ext3 filesystem does not enable write barriers by default. +Write barriers enforce proper on-disk ordering of journal commits, making +volatile disk write caches safe to use, at some performance penalty. The ext3 +filesystem does not enable write barriers by default. Be sure to enable +barriers unless your disks are battery-backed one way or another. Otherwise +you risk filesystem corruption in case of power failure. .TP .BI commit= nrsec Sync all data and metadata every @@ -1932,6 +1936,15 @@ manual page. Enable POSIX Access Control Lists. See the .BR acl (5) manual page. +.TP +.BR barrier=none " / " barrier=flush " +This enables/disables the use of write barriers in the journaling code. +barrier=none disables it, barrier=flush enables it. Write barriers enforce +proper on-disk ordering of journal commits, making volatile disk write caches +safe to use, at some performance penalty. The reiserfs filesystem does not +enable write barriers by default. Be sure to enable barriers unless your disks +are battery-backed one way or another. Otherwise you risk filesystem +corruption in case of power failure. .SH "Mount options for romfs" None.