on 08/06/2011 19:55 Jeremy Chadwick said the following: > On Wed, Jun 08, 2011 at 07:40:03PM +0300, Andriy Gapon wrote: >> on 08/06/2011 19:26 Jeremy Chadwick said the following: >>> I have the exact same question except not with regards to labels but >>> toggling TRIM capability on the root filesystem. >>> >>> - Start system >>> - At loader, boot single-user (option 4) >>> - At prompt choose /bin/sh >>> - mount -a >> >> I think that this is a culprit. > > I'll try removing this step. > >>> - tunefs -t enable /dev/ada0s1a --- fails >> >> Shouldn't you have / mounted r/o here? >> BTW, AFAIR, *re*-mounting root read-only won't help; it needs to have never >> been >> mounted r/w. > > I'm a little confused by this sentence, so my apologise in advance. / > is mounted read-only in single-user by default. Did you mean I should > make it r/w by doing "mount -u -o rw /" ? I may have omitted this step.
No. My English is not perfect it seems - my point was that you should never mount your root fs r/w if you want to do tunefs on it. > I will re-verify the exact procedure and exact steps in a moment, and > reply here. > >>> - sysctl kern.geom.debugflags=16 >>> - tunefs -t enable /dev/ada0s1a --- works >>> - tunefs -p /dev/ada0s1a -- shows TRIM enabled >>> - reboot >> >> I think that at this step your superblock on disk gets re-written with its >> copy in >> memory which has never been updated. But not sure. > > Hmm, I sure hope that isn't the case. I think that this is the case. > That would mean the only time a > person can use tunefs on a root filesystem is when they either do it > manually during the FreeBSD installation (adding "-t" to the list of > newfs flags in the filesystem creation UI), or if they boot off of some > other medium (USB flash drive, CD, PXE, etc.). Or when your root fs is mounted r/o, which is not as bad as what you listed above. -- Andriy Gapon _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[email protected]"
