btrfs

What is UUID_SUB?

What is UUID_SUB? The output from blkid shows a post called UUID_SUB on my BTRFS-volumes. What does that mean and where can I find more info? /dev/sdc: LABEL="example" UUID="e7c116be-e3ba-4097-857b-12a1f4e9f753" UUID_SUB="b263e0c0-1714-48f1-8706-f97dec03b355" BLOCK_SIZE="4096" TYPE="btrfs" Asked By: PetaspeedBeaver || Source UUID_SUB shows the subvolume UUID (see man libblkid for details). For more on BTRFS subvolumes, see the relevant …

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Which filesystems support the C attribute?

Which filesystems support the C attribute? On BTRFS filesystems you can disable CoW for a file using the C file attribute, like this: chattr +C filename I expected this to work on ZFS too, since it is also a CoW filesystem, but the attribute cannot be set (maybe ZFS cannot function without CoW). So what …

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Ubuntu boot stuck at "btrfs loaded crc32c=crc32c-intel zoned=yes fsverity=yes"

Ubuntu boot stuck at "btrfs loaded crc32c=crc32c-intel zoned=yes fsverity=yes" I’ve been stuck on this for 5 days now, so any help would be appreciated> This is a bare metal server on OVH running Ubuntu 22.04. The OS was installed on a RAID1 array using both "system disks" (these are regular SSDs). The issue appears when …

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How can I force swap to use all of my BTRFS swap file?

How can I force swap to use all of my BTRFS swap file? I created a BTRFS swap file using the following command: $ btrfs filesystem mkswapfile -s 8G SwapFile However, swap only uses 1GB of the swap file, as shown by the following command sequence: $ du -csh SwapFile ; free 8.0G SwapFile 8.0G …

Total answers: 2

Equivalent of `btrfs send` and `btrfs recv` for bcachefs

Equivalent of `btrfs send` and `btrfs recv` for bcachefs I’m using a setup I consider to be rather fragile and prone to failure involving LUKS, LVM, btrfs, and bcache. I have used btrfs for a long time, and have never experienced any significant issues with it. But, it doesn’t support caching, nor does it handle …

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Snapshots backup problems Ubuntu 23.10

Snapshots backup problems Ubuntu 23.10 I tried to use Timeshift for a snapshot backup but when I installed it , it can not find my root partition as it is not in a shape like /@ and /@home. How to get that ? I am using Ubuntu 23.10. During installation I did manual partitioning : …

Total answers: 1

Mount specific removable media with mount options by default

Mount specific removable media with mount options by default I run Ubuntu Mate 22.04 and I have a USB mass storage device (aka USB-Stick) that is formatted with btrfs. I know it’s partition UUID and label and I want it specifically to be mounted with specific mount options. In particular I want to enable file …

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btrfs receive to <mount-point>/?

btrfs receive to <mount-point>/? Suppose I have a BTRFS filesystem A with a read-only subvolume at <mount-point-A>/snaps/good-one. I want to create a BTRFS filesystem B (could be on the same or another machine) which will contain the contents of that subvolume at <mount-point-B>/ — in normal read-write mode. Is there any way to employ btrfs …

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Why does btrfs /home/ partition keep mounting ro on login?

Why does btrfs /home/ partition keep mounting ro on login? I’m having a problem with my /home mounted on /dev/sdb1 on a btrfs partition. It keeps mounting roeven after I booted from a USB stick, ran check and confirmed that it could be mounted rw. Why would it still mount ro when booting on my …

Total answers: 2

What optimizations are turned on with the mount option "ssd"?

What optimizations are turned on with the mount option "ssd"? "Debian 12 Bookworm Minimal Install w/BTRFS " by JustAGuy Linux at 8:28 he sets an option for ssd, mount -o … ssd … What is the option ssd? When should it be used, and when should it not be used? I don’t see it documented …

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Advice? External USB harddrive accidentally unplugged (no activity at time). Re-plugged, but `mountpoint`/`findmnt`/`lsblk` disagree if mounted?

Advice? External USB harddrive accidentally unplugged (no activity at time). Re-plugged, but `mountpoint`/`findmnt`/`lsblk` disagree if mounted? [(This really isn’t an unbuntu-specific question, but yeah…)] So I just accidentally bumped and and unplugged the cable on an external USB harddrive. There was no activity at the time. It’s btrfs (one big partition the whole drive, about …

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Where does grub-install take the arguments for grub-mkimage from?

Where does grub-install take the arguments for grub-mkimage from? When I run grub-install /dev/vda -v I see this line in the output: grub-mkimage –directory ‘/usr/lib/grub/i386-pc’ –prefix ‘(,msdos1)/boot/grub’ –output ‘/boot/grub/i386-pc/core.img’ –dtb ” –format ‘i386-pc’ –compression ‘auto’ ‘ext2’ ‘part_msdos’ ‘biosdisk’ How do I configure GRUB to add specific modules in the list of grub-mkimage arguments? Backstory: I …

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how to access linux data from another machine physically?

how to access linux data from another machine physically? My laptop is failing, but I know for sure the hard drive is okay and fine. I want to take the data inside it, I connect my laptop’s hard drive (open suse tumbleweed with btrfs filesystem) to my desktop pc (ubuntu 22.04.01 LTS with vfat filesystem), …

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How does linux know what btrfs subvol to mount as root?

How does linux know what btrfs subvol to mount as root? I have a btrfs filesystem that looks like this: root_subvol # subvolid=5 – the root subvolume for the btrfs filesystem – snapshots/ # Folder that contains btrfs snapshots of the subvol_root that I take before I do system updates – subvol_root/ # A btrfs …

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Move the root from one subvolume to another in BTRFS

Move the root from one subvolume to another in BTRFS I want to install Ubuntu in the BTRFS @root subvolume, but the Ubuntu installer does not allow changing the default subvolumes and installs in @ and @home. I’m trying to create a @root subvolume after installation, but I have a problem. I need to edit …

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BTRFS Recover deleted files without snapshot

BTRFS Recover deleted files without snapshot I deleted all the files on a /dev/sdb1 4TB disk. This was done with the rsync –delete command. Before being stopped the rsync wrote about 10GB of data. Of course there is no snapshot on the disk. The btrfs filesystem was mounted to the /home/user/Downloads folder. So I wanted …

Total answers: 1

Trim and btrfs with raid1

Trim and btrfs with raid1 I know that btrfs support trim/discard, as a mount option or manually (fstrim -A). I want to made a raid1 of ssd, I will get any problem with trim? Asked By: elbarna || Source Seems all ok on btrfs raid1 on Slackware 15 fstrim -Av /boot: 912,8 MiB (957186048 bytes) …

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BTRFS Raid1..a little confused

BTRFS Raid1..a little confused I have setup a BTRFS Raid1, I have re-balanced it 2 weeks ago. Now btrfs df said… root@slackware:~# btrfs filesystem df /mnt Data, RAID1: total=4.14TiB, used=4.08TiB System, RAID1: total=32.00MiB, used=608.00KiB Metadata, RAID1: total=6.00GiB, used=5.20GiB GlobalReserve, single: total=512.00MiB, used=0.00B my questions are..suppose I lost one hd, I will lost data? How to …

Total answers: 1

BTRFS: problems with raid1?

BTRFS: problems with raid1? btrfs df / report this btrfs filesystem df / Data, RAID1: total=4.26TiB, used=4.16TiB System, RAID1: total=8.00MiB, used=752.00KiB System, single: total=32.00MiB, used=0.00B Metadata, RAID1: total=7.00GiB, used=5.98GiB Metadata, single: total=1.00GiB, used=0.00B GlobalReserve, single: total=512.00MiB, used=0.00B WARNING: Multiple block group profiles detected, see ‘man btrfs(5)’. WARNING: Metadata: single, raid1 WARNING: System: single, raid1 I …

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