On Sat, February 7, 2009 7:08 am, Bill Nottingham wrote: > Dan Williams (dan.j.williams@xxxxxxxxx) said: >> Actually no, your not necessarily stuck with the mdmon from boot. In >> a pinch you could "mdmon /proc/mdstat /". > > Not really. > > You state: > >> One might say "just set the dirty bit, terminate, and wait for the >> mdmon in the rootfs to take over". The problem is that a disk could >> fail in this window, and this event needs to be handled before the >> kernel does anything else to the array. > ... >> The clean bit can be set as soon as the parity data is in sync with >> the data on the other drives. We typically wait for some period of >> write-inactivity to avoid needlessly touching the metadata after every >> write. > > You shut down the machine. After a while, you get to the point where > you're getting ready to unmount the filesystem. Since mdmon's running > on it (if you started it post boot), you have to kill it. After that > point, there are going to be writes (a final sync, if nothing else, > when you unmount the filesystem.) And you won't be able to set any > RAID metadata flags then, as the daemon won't be running. So, doing > a later run of "mdmon /proc/mdstat" doesn't fully protect you. ??? Last time I checked, Linux would not unmount the root filesystem. It just remounts it 'read-only'. Is that going to change? NeilBrown -- To unsubscribe from this list: send the line "unsubscribe initramfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
