On Sun, Jun 04, 2017 at 12:31:34PM -0700, Linus Torvalds wrote: > and in particular the patch in there that just makes UFS use MAX_LFS_FILESIZE: > > https://bugzilla.kernel.org/attachment.cgi?id=256853&action=diff > I'm inclined to just apply it, since clearly the default 2G limit > isn't appropriate for UFS, although it would perhaps be a good idea to > figure out just what the true UFS maximum file size can be.. The > on-disk "ui_size" field seems to be a 64-bit entity, so > MAX_LFS_FILESIZE is certainly better, but there's probably some index > tree limit that depends on the block size or whatever. Depends. There had been a lot of UFS variants (hell, ext2 is one), so limits differ. They are also kernel-dependent. One hard limit is the same as in ext2 - indirect blocks contain pointers to blocks, so you get (10 + n + n^2 + n^3)*block_size, where n is block_size / pointer size. For UFS pointers are 32bit (UFS2 is trickier, but we don't support that). Another pile of fun is VM-related and that varies from kernel to kernel. FWIW, current FreeBSD has no problems with that (32bit included), but there had been 4.4BSD variants that used to.
