Christoph Anton Mitterer posted on Sun, 27 Dec 2015 04:38:56 +0100 as excerpted:
> I've just noted the following behaviour: > > # btrfs scrub start -Bdr / > scrub device /dev/sda2 (id 1) done > scrub started at Sun Dec 27 01:59:05 2015 > and finished after 00:04:04 > total bytes scrubbed: 29.39GiB with 0 errors > scrub device /dev/sdb2 (id 2) done > scrub started at Sun Dec 27 01:59:05 2015 > and finished after 00:04:08 > total bytes scrubbed: 29.39GiB with 0 errors > > => that works as expected > > However: > # btrfs scrub start -Bdr /dev/disk/by-label/system > scrub device /dev/sdb2 (id 2) done > scrub started at Sun Dec 27 01:53:18 2015 > and finished after 00:04:01 > total bytes scrubbed: 29.37GiB with 0 errors > => seems to scan only sdb2 (which is where /dev/disk/by-label/system > points to) at least, no output is given for sda2 I'd call that NOTABUG. As the btrfs-scrub manpage suggests: * When you point scrub at a mountpoint, it scrubs all devices composing that filesystem. (The manpage specifically says "all devices of the filesystem identified by <path>". Emphasis on _ALL_DEVICES_ if given a normal path.) * When you point scrub at a specific device, it scrubs that specific device. (The manpage continues ... "or on a single <device>." Emphasis on _SINGLE_DEVICE_ if given a device node.) Since /dev/disk/by-*/* are symlinks to various block-device nodes, it follows that if you point scrub at them, only the device pointed at is scrubbed, exactly as one might expect based on the manpage. -- 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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
