16TiB ext4

[Curtis Doty]

12:16pm Eric Sandeen said:

> The real limit, IIRC, is (2^32 - 1) blocks, or 4k shy of 16T for 4k blocks.
>
> This is a little unfortunate since "lvcreate -L16T" is so handy, but it
> won't mkfs properly.  (ext3 should have the same limitation).
>
> We should probably make mkfs just silently lop off one block if it
> encounters a boundary condition like this ...
>

Ah, thanks Eric! That would be smart.

I'm trying to workaround, but...

----8<----
# mkfs.ext4 /dev/foo/bar $[2**32-1]
mke2fs 1.41.3 (12-Oct-2008)
mkfs.ext4: Size of device /dev/phd/dc1a too big to be expressed in 32 bits
         using a blocksize of 4096.
# mkfs.ext4 /dev/foo/bar 42
# mkfs.ext4
Usage: mkfs.ext4 [-c|-l filename] [-b block-size] [-f fragment-size]
         [-i bytes-per-inode] [-I inode-size] [-J journal-options]
         [-G meta group size] [-N number-of-inodes]
         [-m reserved-blocks-percentage] [-o creator-os]
         [-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
         [-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
         [-T fs-type] [-jnqvFSV] device [blocks-count]
----8<----

It doesn't appear to support the blocks-count option anymore. :-( Or did 
it ever?

../C