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Is it possible to balance Btrfs across all devices?
The filesystem can be balanced to spread the extents across all the devices. The btrfs balance operation will take some time. It reads in all of the FS data and metadata and rewrites it across all the available devices.
Which is an example of using btrfs with multiple devices?
The btrfs balance operation will take some time. It reads in all of the FS data and metadata and rewrites it across all the available devices. Depending on the usage scenario that is not needed, one example would be adding a new device to a RAID 1 filesystem whose existing devices still have enough space left.
Is it possible to pair all chunks of Btrfs?
BTRFS allocates chunks to devices in a round-robin fashion, which can cause lost space if you have devices of different sizes. There is a quasi-round-robin patch in the pipeline to improve on this. Of course, it is still impossible to pair all chunks on different devices if you have a 500GB and a 2TB disk.
Can you add a second disc to a Btrfs disk?
If you did not change this then likely you will have no problem adding the second disc and running re-balance. because only the metadata will be copied to both discs (you can see your metadata size with btrfs filesystem df / ). Just be aware that if either of your disks fails you loose data.
Can you use RAID-1 on a Btrfs device?
Basically if your Btrfs device had RAID-1 and you convert it you normal single mode, your disk space will double: This is a pretty nice feature that is made possible by the unique design in Btrfs. For example ZFS does not have a balance command at all.
What happens if a disk fails in Btrfs?
If a disk in a btrfs RAID 1 array fails, then btrfs will refuse to mount that filesystem and error messages will be visible in the syslog. If it was the root filesystem, then the system will refuse to boot normally and the system will usually boot to an initramfs console.
When does Btrfs need to be mounted in degraded mode?
But, if a device is missing or the super block has been corrupted, the filesystem will need to be mounted in degraded mode: btrfs device delete missing tells btrfs to remove the first device that is described by the filesystem metadata but not present when the FS was mounted.