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304 views

Repair btrfs RAID? Error: Inappropriate ioctl for device

I have a RAID5 btrfs with 8 disks and a hard disk died and just disappeared from the list. Now I tried removing it but got an error: ERROR: error removing the device '/dev/sdb' - Inappropriate ioctl ...
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1answer
1k views

expose Btrfs snapshots with samba4 and vfs_shadow2

I'm trying to implement the vfs_shadow2 module with samba 4.2 running on Fedora 22 to get windows explorer feature "previous versions" on clients to work. The shared "folder" is an Btrfs subvolume in ...
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164 views

partclone.btrfs thousands of correctable csum errors

I just cloned a btrfs file system from one disk to another using partclone.btrfs --dev-to-dev. Afterwards, I mounted the cloned file system and started a scrub to see if everything is in order. After ...
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1answer
2k views

GRUB2: /boot as BTRFS subvolume

Aside from /boot, all my partitions (including root, /) are BTRFS subvolumes. I'm switching to BTRFS RAID1, and for the sake of integrity, want to include /boot within the BTRFS partition. Preferably ...
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40 views

btrfs not distributing data to smaller disks in 4-disk RAID1 array

I have a btrfs filesystem composed of four disks of sizes 3TB, 3TB, 1TB, and 1TB, configured in a RAID1 (data and metadata). I've noticed that btrfs doesn't seem to want to use the smaller disks at ...
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2answers
154 views

Cannot remove directory on btrfs

There is an object on btrfs file system called "????????? ??????" which probably some improperly deleted or copied temporary file or directory. And which can't be removed with common commands: rm, rm -...
2
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1answer
110 views

BTRFS size on disk 200x larger than actual size

Why is BTRFS so grossly misquoting the size of small files on my filesystem? [pi@rpi scipy]% cat __init__.py | wc -c # literal byte count 4729 [pi@rpi scipy]% du --apparent-size -h ...
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193 views

Why does BTRFS seem to have comically large allocations for metadata? [duplicate]

I've recently discovered the marvel of a modern filesystem, btrfs. After playing with it for a few hours, I decided to dive straight in and converted my entire /home partition using the btrfs-convert ...
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1answer
3k views

How does btrfs scrub work and what does it do?

What exactly does btrfs scrub do? According to the manual page, which is totally unclear, it does some error checking. What kind of error checking? How reliable is it? Is it able to recover some ...
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2answers
2k views

btrfs convert from raid1 to raid5

Is it possible to easily convert a btrfs raid1 to a raid5. I mean at the end of the day. Its really just two mirrored drives. So I would think this should be easy to do. I want to now have 3 3TB ...
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1answer
61 views

Is a btrfs RAID1 mountable if the added device isn't available/offline/failed/degraded?

Assume I created a RAID1 with btrfs's functions (btrfs device and btrfs balance subcommands instead of mdadm) like so: btrfs device add /dev/sdxZ /dev/sdxY btrfs balance start -dconvert=raid1 -...
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90 views

Is there a difference between writing to a btrfs snapshot or to its original?

After creating a btrfs subvolume produces two directories (one representing the subvolume, the other the writable snapshot). When writing to one of them, the changes are not reflected in the other, so ...
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103 views

After a crash computer will not boot with btrfs drive

So since I started using btrfs, when my computer crashes (mainly because battery ran out but on any crashe i had up until now) it does not boot anymore (the issue seems that the kernel cannot mount ...
3
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1answer
291 views

btrfs restore specific directory

I have a damaged btrfs filesystem, and I am using btrfs restore to restore it. It seems to work. The problem is that the damaged filesystem is quite huge, and I need only to restore just one ...
3
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1answer
108 views

Understanding metadata usage behavior in a newly converted btrfs filesystem

I have a 5 TB hard drive with 3.3 TiB (as reported by du) of media files in 119k files and directories; the average file size was about 28 MiB. I converted the ext4 partition into btrfs with btrfs-...
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2answers
1k views

What would be the correct mount options for a seperated btrfs /home partition in /etc/fstab?

After I read a bit about Btrfs I figured out it has many features I would like to use in the future, like snapshots, compression, defrag, enhancemence for SSD drives and so on. So I decided to ...
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1answer
218 views

Btrfs volume management for normal home user

Btrfs is by design for enterprise use, but that doesn't stop normal home users from using it. By normal home user, I mean those people who don't use complicated setup like mirroring, or any level of ...
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2answers
582 views

Btrfs RAID1 SSD + non-SSD

My laptop has two disks, a SSD and a traditional magnetic disk. I plan to make a partition on the mag disk equal in size the SSD and set up BTRFS RAID1. This I know how to do. The only reason I'm ...
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1answer
3k views

Btrfs: RAID 1 on 3+ devices

I currently have a Btrfs partition with four devices: three 3 TB drives and a 4 TB drive. Data and metadata are RAID 10, so I have 6 TB of usable space, which is almost full. I'd anticipated that RAID ...
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1answer
62 views

How to rsync the / folder properly?

I have a btrfs snapshot of / and I want to rsync it with my current / folder. As form of "rollback" if you want. My question is what folder should I avoid for instance I should use -x option to ...
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94 views

How many volumes should I add in my btrfs?

How much overhead does a single physical partition add to a btrfs volume? ps aux | grep btrfs | wc -l results in 102. I have 4TBx4 in my NAS and 16GB RAM and Core i3 processor. The NAS also hosts a ...
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1answer
745 views

How to delete a file in all snapshots on a btrfs system?

I've set up a sophisticated backup scheme with hourly, daily, weekly, monthly backups that take up (thanks to the glory of the btrfs cow-filesystem) almost no extra space on the device. But ...
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1answer
157 views

Ubuntu btrfs snapshot cannot mv into /home

I want to be able to take a snapshot and restore it in real time. This works in Fedora and does a live "rollback" : btrfs subvolume snapshot /home /home/snapshot mv /home/snapshot /home But in ...
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1answer
3k views

Why shouldn't I use btrfs for /home?

I'm fairly new to both GNU/Linux and btrfs, but I've decided I want to make my next computer (a desktop with one HDD) use Linux with btrfs as the filesystem. However, I've seen some advice online that ...
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37 views

Files in $HOME losing executable bit

On my laptop running Arch, I have a bunch of git repositories cloned under ~/git. My problem is that from time to time (maybe once in a month or so), all the executable files inside the clones will ...
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1answer
332 views

btrfs check: “Couldn't open file system”

When I run btrfs check /dev/sda1, it returns "Couldn't open file system," whether /dev/sda1 is mounted or not. Why? (cf. this)
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3answers
2k views

Finding files with BTRFS Uncorrectable Errors

I have a question concerning unrecoverable errors on a BTRFS file system. Specifically, I've run a BTRFS Scrub recently after experiencing a problem with one of my RAM sticks and it seems to have ...
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1answer
297 views

BTRFS filesystem, compression and copy on write

I'm planning about moving from etx4 to BTRFS filesystem on my pc and backup server. I'm very interested in the BTRFS snapshot feature (I have understood it uses the copy on write feature) and the ...
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2answers
2k views

What is Btrfs's disk space caching?

I noticed in my syslog that BTRFS reports enabling "disk space caching". What is Btrfs's "disk space caching"?
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1answer
960 views

how to delete btrfs snapshot?

sudo btrfs subvolume show / outputs / Name: @ uuid: 1f0da442-cdf3-144c-a4ce-f6c06248cfde Parent uuid: - Creation time: 2014-08-16 19:06:51 Object ...
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1answer
231 views

Online Drive Replacement: BTRFS with RAID 6

on a testing machine I installed four HDDs and they are configured as RAID6. For a test I removed one of the drives (/dev/sdk) while the volume was mounted and data was written to it. This worked well,...
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61 views

How come system snapshots are so small in size?

So let’s say a have a file called bob with the size of 10GB in /home. I make a snapshot of /home and delete the original bob file. However I can still access the bob file because I have a snapshot it. ...
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2answers
388 views

Mirror / backup laptop btrfs drive to sometimes connected external USB disk

I have a laptop with an internal drive using Btrfs. There are several subvolumes and snapshots on here. I want a copy of this drive to be made periodically to an external USB disk of approximately the ...
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1answer
271 views

BTRFS or LVM heterogeneous RAID

I'm entertaining creating a largish (3.5TB+) backup server for my family. I already own enough hardware, and I don't want to buy any more right now. The config I envision look like this: Two 1TB ...
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2answers
533 views

Btrfs raid level for large NAS (8+ 5tb disks)

I'm planning to build a new NAS to store a large amount of media (20tb+). I would like to use btrfs for both the NAS and the backup (might be a separate system, not sure yet) I want to use raid1 or ...
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1answer
4k views

ext4 vs btrfs performance on SSD array

I am observing something that I cannot explain. I am trying to come up with a good filesystem configuration using HP P420i controller and SSDs. Out of curiosity I have tried BTRFS (still unstable so I ...
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2answers
321 views

Is there something analogue to LVM logical volumes in BTRFS?

I like the way BTRFS does snapshots and subvolumes but it does not feel right to use LVM just because I want my logical volume to be of certain size. Is there something analogue to LVM logical ...
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1answer
247 views

How do I deal with BTRFS raid1 when usb disk device mappings changes?

I created a btrfs raid1 one by using "mkfs.btrfs /dev/sdc1 /dev/sdg1". It worked fine but next time I restarted my pc it seemed like the sdg device became sdf therefor btrfs refused to mount this ...
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114 views

btrfs won't run from cron

I'm trying to set up a cron job to create a btrfs subvolume snapshot of my root partition. The command works perfectly if I run it from the command line, but nothing happens at the scheduled cron time....
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1answer
2k views

How to snapshot a btrfs root file system (snapshot of /)?

I have Fedora 20 and when I installed it I choose to go with btrfs as file system, by many reasons but mainly to have snapshots available. But I can't seem to create a snapshot of /. I can snapshot ...
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3answers
3k views

How to monitor BTRFS filesystem raid for errors?

I saw some documentation on a daemon that can execute a program/script for various BTRFS events, but I cannot find it anymore. How can I have a script/program be executed on a drive failure for a ...
4
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1answer
1k views

partitioning and subvol strategy with btrfs

I'm new to btrfs and I'd like some advice on partitioning and subvolume strategy. The system is a light-duty web server, and assume it only has a single disk. With ext filesystems, I've always ...
2
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1answer
482 views

Is it possible to convert a btrfs RAID5 to a RAID6 with the same disks without losing data?

How would I convert an existing RAID5 (single parity) btrfs setup to a dual parity RAID6 configuration given enough free available disk space, using the same disks, without swapping out data ? ...
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1answer
157 views

RAID 0 or btrfs on two SSDs?

I have two 500 GB SSD's, and I would like to combine the two in some way to have 1 250 GB NTFS partition, and 1 750 GB btrfs or ext4 partition. As far as I see, I have two options: the Intel Rapid ...
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3answers
801 views

Is RAID1 or similar needed for btrfs/ZFS to protect against bit rot?

I'm running a file server using Linux software raid, set up as raid6. As filesystem I've chosen btrfs. However, I'm not using btrfs own raid6 implementation as it's not very stable yet. So basically, ...
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1answer
3k views

How to recover this btrfs error?

I have a btrfs file system that cannot be mounted anymore. I resetted the computer and after boot a Java process crashed, showing a core dump with much btrfs stuff on the stack. After that happened, ...
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1answer
168 views

Is there a way to show RAID details in a similar way to MDADM?

I find mdadm --detail <device> very useful when I need to know what is going on with the device (/proc/mdadm too). Example: /dev/md0: Version : 1.2 Creation Time : Mon Mar 4 08:35:...
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1answer
217 views

btrfs does not show drive as missing

I am trying out btrfs and I noticed some funny behaviour: I have two drives in a raid 1 configuration. sudo btrfs fi show Label: none uuid: 52b9c6f6-ce5c-4727-861e-e2fd012e475f Total devices 2 ...
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2answers
3k views

Reasoning behind hosting virtual disk images on BTRFS Filesystem

I have been reading about BTRFS and ZFS for a while and while I do appreciate the benefits of CoW when hosting important files I am currently puzzled by the following dilemma: Given that both ZFS and ...
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1answer
1k views

Full BTRFS partition unusable

I have an extremely critical set of circumstances. I installed snapper on my Fedora 20 box. It created around 20 snapshots. My btrfs partition is now full of snapper subvolumes. My partition became ...