Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Thu, Apr 25, 2013 at 09:49:59PM +0200, Lars Ellenberg wrote: > On Thu, Apr 25, 2013 at 01:59:52PM +0000, Prater, James K. wrote: > > We are using RHEL 6.4 this parameter set in the global common > > configuration file and also on the haresources mount attributes. The > > question is that I cannot change this parameter on the fly with the > > "mount -o remount,barrier=1". With "tune2fs -l /dev/drbd0", > > nobarrier is still enabled. BTW. If you try to *enable* barrier on the mount: you need a FLUSH/FUA enabled kernel, and drbd 8.3.15 or drbd 8.4.3 for that. (ok, strictly > 8.3.14, or > 8.4.2) Earlier versions did not announce the FLUSH capability to upper layers. Regarding "tune2fs -l", I'm not exactly sure where your problem is. If it is just that "tune2fs -l" still reports Default mount options: ... nobarrier, that just reports what is stored in the superblock. mount, or remount, will not change the flags stored in the superblock, but only the options used for the current mount. (as reflected in /proc/mounts) If you want to clear the flag in the superblock again, tune2fs -o ^nobarrier should do the trick. > The question is, does this parameter > > propagates into the EXT4 attribute stack? Or do I have to clear it > > in both drbd and the mount. > > Please don't hijack threads. > > The DRBD setting "barrier" has nothing to do with the file system mount > option "barrier" -- other than that, if no volatile caches are involved, > it is safe (and usually a performance gain) to disable both of them. > > You change the DRBD setting in the DRBD configuration, > or with drbdadm/drbdsetup. > > You change mount options via fstab, or tune2fs and equivalents, > and remount. > > -- > : Lars Ellenberg > : LINBIT | Your Way to High Availability > : DRBD/HA support and consulting http://www.linbit.com > _______________________________________________ > drbd-user mailing list > drbd-user at lists.linbit.com > http://lists.linbit.com/mailman/listinfo/drbd-user -- : Lars Ellenberg : LINBIT | Your Way to High Availability : DRBD/HA support and consulting http://www.linbit.com DRBD® and LINBIT® are registered trademarks of LINBIT, Austria. __ please don't Cc me, but send to list -- I'm subscribed