what is the max files per directory in EXT4?

问题:

What is the limit of EXT4, what i found is only EXT3, and other links only suppositions and not a real number?

Can you please provide me: max number per directory, max size?

回答1:

It depends upon the MKFS parameters used during the filesystem creation. Different Linux flavors have different defaults, so it's really impossible to answer your question definitively.

回答2:

Follow-up on @Curt's answer. The creation parameters can determine the number of inodes, and that's what can limit you in the end. df's -i switch gives you inode info.

(env)somesone@somewhere:/$ df -iT
Filesystem     Type       Inodes  IUsed    IFree IUse% Mounted on
/dev/root      ext4     25149440 612277 24537163    3% /
devtmpfs       devtmpfs  3085602   1418  3084184    1% /dev
none           tmpfs     3086068      2  3086066    1% /sys/fs/cgroup
none           tmpfs     3086068    858  3085210    1% /run
none           tmpfs     3086068      1  3086067    1% /run/lock
none           tmpfs     3086068      1  3086067    1% /run/shm
none           tmpfs     3086068      4  3086064    1% /run/user

This is a Linode box BTW, so it's virtualized environment. The number I look at is 24537163, that's how many free inodes the root fs has. Note, that more than 10K files in a directory can cause difficulties for many tools. 100K can be really hard on utilities.

See also: https://serverfault.com/questions/104986/what-is-the-maximum-number-of-files-a-file-system-can-contain