On Sat, Mar 13, 2021 at 5:22 AM Thomas <74cmo...@gmail.com> wrote: > Gerät Boot Anfang Ende Sektoren Größe Kn Typ > /dev/sdb1 2048 496093750 496091703 236,6G 83 Linux
> However the output of btrfs insp dump-s <device> is different: > thomas@pc1-desktop:~ > $ sudo btrfs insp dump-s /dev/sdb1 | grep dev_item.total_bytes > dev_item.total_bytes 256059465728 sdb1 has 253998951936 bytes which is *less* than the btrfs super block is saying it should be. 1.919 GiB less. I'm going to guess that the sdb1 partition was reduced without first shrinking the file system. The most common way this happens is not realizing that each member device of a btrfs file system must be separately shrunk. If you do not specify a devid, then devid 1 is assumed. man btrfs filesystem "The devid can be found in the output of btrfs filesystem show and defaults to 1 if not specified." I bet that the file system was shunk one time, this shrunk only devid 1 which is also /dev/sda1. But then both partitions were shrunk thereby truncating sdb1, resulting in these errors. If that's correct, you need to change the sdb1 partition back to its original size (matching the size of the sdb1 btrfs superblock). Scrub the file system so sdb1 can be repaired from any prior damage from the mistake. Shrink this devid to match the size of the other devid, and then change the partition. > Gerät Boot Anfang Ende Sektoren Größe Kn Typ > /dev/sda1 * 2048 496093750 496091703 236,6G 83 Linux > > thomas@pc1-desktop:~ > $ sudo btrfs insp dump-s /dev/sda1 | grep dev_item.total_bytes > dev_item.total_bytes 253998948352 This is fine. The file system is 3584 bytes less than the partition. I'm not sure why it doesn't end on a 4KiB block boundary or why there's a gap before the start of sda2...but at least it's benign. -- Chris Murphy
