Physical disk layout


This shows the on-disk format of a BTRFS file system on the most zoomed-out level. BTRFS includes a device mapper functionality where a single logical file system can be spread over multiple physical disks, and a logical block can have multiple copies of it stored on disk. Here we assume the file system has only one physical disk and there are no RAID features enabled.

This page shows the layout of the phyiscal disk. It is organized in "chunks", typically a few megabytes to a gigabyte in size, with possibly some unassigned space in between. There are three types of chunks:

The first column in the following table shows the physical address of a chunk and the second column shows its logical address. You can click on the metadata or system chunks to find out how they are laid out.

0unassigned, 13 MiB
d00000d00000data chunk, 8 MiB
15000001500000system chunk, 8 MiB
1d000001500000system chunk, 8 MiB
25000001d00000metadata chunk, 256 MiB
125000001d00000metadata chunk, 256 MiB
2250000011d00000data chunk, 320 MiB
3650000025d00000data chunk, 320 MiB
4a50000039d00000data chunk, 320 MiB
5e5000004dd00000data chunk, 320 MiB
7250000061d00000data chunk, 320 MiB
8650000075d00000data chunk, 320 MiB