Hi, I finished repartition of devices /dev/sda + /dev/sdb now. On both devices the first partition is equal in size: $ sudo fdisk -l /dev/sda Festplatte /dev/sda: 238,47 GiB, 256060514304 Bytes, 500118192 Sektoren Festplattenmodell: SanDisk SD8SBAT2 Einheiten: Sektoren von 1 * 512 = 512 Bytes Sektorgröße (logisch/physikalisch): 512 Bytes / 512 Bytes E/A-Größe (minimal/optimal): 512 Bytes / 512 Bytes Festplattenbezeichnungstyp: dos Festplattenbezeichner: 0x0914a19b
Gerät Boot Anfang Ende Sektoren Größe Kn Typ /dev/sda1 2048 497027071 497025024 237G 83 Linux /dev/sda2 497027072 500118191 3091120 1,5G 82 Linux Swap / Solaris $ sudo fdisk -l /dev/sdb Festplatte /dev/sdb: 238,47 GiB, 256060514304 Bytes, 500118192 Sektoren Festplattenmodell: SanDisk SD9TB8W2 Einheiten: Sektoren von 1 * 512 = 512 Bytes Sektorgröße (logisch/physikalisch): 512 Bytes / 512 Bytes E/A-Größe (minimal/optimal): 512 Bytes / 512 Bytes Festplattenbezeichnungstyp: dos Festplattenbezeichner: 0xf23fc590 Gerät Boot Anfang Ende Sektoren Größe Kn Typ /dev/sdb1 2048 497027071 497025024 237G 83 Linux However, the output of btrfs insp dump-s <device> is still different: $ sudo btrfs insp dump-s /dev/sda1 | grep dev_item.total_bytes dev_item.total_bytes 254476812288 $ sudo btrfs insp dump-s /dev/sdb1 | grep dev_item.total_bytes dev_item.total_bytes 256059465728 Can you please advise how to fix this? My understanding is that size of btrfs superblock must be equal on both devices. THX Am 13.03.21 um 19:02 schrieb Chris Murphy: > 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. > >
