Re: What is max size of ext2fs?

Stephen C. Tweedie (sct@redhat.com)
Mon, 1 Feb 1999 13:18:24 GMT


Hi,

On Sun, 31 Jan 1999 10:08:22 +0100, ralf@uni-koblenz.de said:

> There are different limits. We've got a limit for the size of block
> devices and a limit given by the structure of ext2. The latter is given
> by the 32bit pointers used in inodese and indirect block pointer blocks
> etc. 32bit pointers == 4GiBlocks, 4GiBlocks * blocksize is therefore
> the limit. The common blocksize is 1kb, so the ext2 limit is 4TB.

That is a purely theoretical limit. ext2 can only sit on a single block
device at once: it cannot span block devices. The block device layer
_cannot_ address 4TB: 2^32 * 512 bytes (the sector size) is 2TB, which
is a hard upper limit on any block device for now. On Linux, you cannot
make an ext2fs filesystem larger than that (and if we find any sign
extension problems in the block IO request layers, then 1TB becomes the
limit).

--Stephen

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