Sebastian Gottschall posted on Thu, 19 Jan 2017 11:06:19 +0100 as excerpted: > I have a question. after a power outage my system was turning into a > unrecoverable state using btrfs (kernel 4.9) > since im running --init-extent-tree now for 3 days i'm asking how long > this process normally takes QW has the better direct answer for you, but... This is just a note to remind you, in general questions like "how long" can be better answered if we know the size of your filesystem, the mode (how many devices and what duplication mode for data and metadata) and something about how you use it -- how many subvolumes and snapshots you have, whether you have quotas enabled, etc. Normally output from commands like btrfs fi usage can answer most of the filesystem size and mode stuff, but of course that command requires a mount, and you're doing an unmounted check ATM. However, btrfs fi show should still work and give us basic information like file size and number of devices, and you can fill in the blanks from there. You did mention the kernel version (4.9) however, something that a lot of reports miss, and you're current, so kudos for that. =:^) As to your question, assuming a terabyte scale filesystem, as QW suggested, a full extent tree rebuild is a big job and could indeed take awhile (days). >From a practical perspective... Given the state of btrfs as a still stabilizing and maturing filesystem, having backups for any data you value more than the time and hassle necessary to do the backup is even more a given than on a fully stable filesystem, which means, given the time for an extent tree rebuild on that size of a filesystem, unless you're doing the rebuild specifically to get the experience or test the code, as a practical matter it's probably simply easier to restore from that backup if you valued the data enough to have one, or simply scrap the filesystem and start over if you considered the data worth less than the time and hassle of a backup, and thus didn't have one. -- 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 majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
