Tobias Holst <tobby@xxxxxxxx> schrieb: > Hi > > I am just looking at the features enabled on my btrfs volume. >> ls /sys/fs/btrfs/[UUID]/features/ > shows the following output: >> big_metadata compress_lzo extended_iref mixed_backref raid56 > > So "big_metadata" means I am not using "skinny-metadata", No, both can be enabled at the same time. "big_metadata" means you are using the new default 16k nodesize vs the old default 4k nodesize. I have two btrfs, the main one created early and missing "big_metadata" (it can only be enabled at fs-creation time) and my backup volume which was recreated later from scratch. Both are having "skinny_extents", tho. > "compress_lzo" means I am using compression. "raid56" means I am using > the experimental RAID-features of btrfs. Yep. > But the other two flags are a little bit unclear... I think "extended > _iref" is the "extref" feature of mkfs.btrfs - right? Probably yes. Here's a list you can check against: https://btrfs.wiki.kernel.org/index.php/Changelog > I am not sure about the "mixed_backref" feature. What does it mean? Is > this the "mixed-bg"-feature of mkfs.btrfs? I have this, too. But I think, mixed-bg (mixed block groups, default on very small devices) is different because I certainly don't use that but still have "mixed_backref". So, I cannot say what it is except that it is not the same. > Also I try to change these features. I am missing the skinny extends, > this can be enabled by "btrfstune -x [one device of my raid]", > correct? Yep. Ensure running a capable kernel and use it on the unmounted device. I've done that in the past and it works. > And how can I enable the missing "no-holes"-feature on my volume? Didn't know of that yet, I'd be interested, too. ;-) > Regards, > Tobias Here's some additional info explaining the purpose of various features and defaults: https://btrfs.wiki.kernel.org/index.php/FAQ -- Replies to list only preferred. -- 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
