What happens if I delete lost+found
Solution 1:
fsck will recreate the lost+found directory if it is missing.
On startup most distributions run fsck if the filesystem is detected as not being unmounted cleanly. As fsck creates the lost+found directory if it is missing, it will create it then and place anything that it finds into that directory.
Solution 2:
If you can't or don't want to run fsck
, you can recreate the lost+found
directories with mklost+found
:
mklost+found pre-allocates disk blocks to the lost+found directory so that when e2fsck(8) is being run to recover a filesystem, it does not need to allocate blocks in the filesystem to store a large number of unlinked files. This ensures that e2fsck will not have to allocate data blocks in the filesystem during recovery.
Solution 3:
A pre-existing lost+found directory with a large enough size to contain a large number of unlinked files puts less of a burden on e2fsck to create the directory and grow it to the appropriate size.
It will still attempt to do so, but in the face of a corrupt filesystem, it can be more risky.
Very old fsck's for other filesystems on other platforms were not able to create /lost+found, nor were they able to grow it. This is the history for the rationale of /lost+found. But the current rationale is simply to make e2fsck's job easier.
Solution 4:
If you have no lost+found
, e2fsck
(I have not inspected the code to other fsck
implementations) will offer to create it for you. But, you can recreate it yourself if you want, too; there's nothing particularly special about that directory (at least not from inspecting the code).