From 99ad3805beed9f527830c2d07118718872224e9f Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Fri, 15 May 2015 14:28:26 +0800 Subject: [PATCH] btrfs-progs: Documentation: uuid change Signed-off-by: Qu Wenruo [updated wodring] Signed-off-by: David Sterba --- Documentation/btrfstune.asciidoc | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/Documentation/btrfstune.asciidoc b/Documentation/btrfstune.asciidoc index 9620221..b6edcb2 100644 --- a/Documentation/btrfstune.asciidoc +++ b/Documentation/btrfstune.asciidoc @@ -25,8 +25,22 @@ Enable extended inode refs. -x:: Enable skinny metadata extent refs. -f:: -Allow dangerous changes, e.g. clear the seeding flag. Make sure that you are -aware of the dangers. +Allow dangerous changes, e.g. clear the seeding flag or change fsid. Make sure +that you are aware of the dangers. +-u:: +Change fsid to a random generated UUID or continue previous change operation in +case it was interrupted with the original UUID. +-U :: +Change fsid to . ++ +The should be a 36 bytes string in `printf`(3) format +"%08x-%04x-%04x-%04x-%012x". +If there is a previous unfinished fsid change, it will only continue if the + matches the unfinished one. + +WARNING: Cancelling or interrupting a UUID change operation will make the +filesystem temporarily unmountable. To fix it, rerun 'btrfstune -u' to restore +the UUID and wait it complete. When mounting the new device, btrfs will check whether the seeding flag is set when try to open seeding device. If the user clears the seeding flag of the -- 2.7.4