Is there a maximum limit to the number of subdirectories in a single directory for btrfs like the 64,000 limit in ext4?

(see here: https://stackoverflow.com/questions/22775011/what-is-the-maximum-number-of-subdirectories-allowed-in-ext4)

2 Answers 2


There is no limit, but you cannot create more then 2^64 directories in total.

Btrfs does not have a specific limit for the content of a directory (neither for files, nor for sub-directories). The content is represented as lists, but its length is not limited. However, each directory will need its own inode. As btrfs uses 64-bit integers, there cannot be more then 2^64 inodes in total. That number defines an upper bound for the number of sub-directories that you can create. For details, see the design document.

Note that 2^64 is such a high number that for all practical circumstances, it is unlimited. You will rather run out of disk space until you hit that limit.


If my memory is serving me right, BTRFS doesn't have a subdirectory limit but it has total number of files limit, which is a ridiculously high number of 2^64. I searched google but could not find the document where I saw this from. I think it was an oracle web page. So take it with a grain of salt.

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    – Anthon
    Mar 20, 2016 at 6:20

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