A better ext4 filesystem for Linux
A new Linux filesystem gets rid of the 256-petabyte limit, and adds a checksum feature for the journal. But developers want you to know that it’s not yet ready for production sytems.
Linux’s ext4 filesystem, the successor to ext3, may well be the filesystem many of us are using a few years from now. Things have been relatively quiet on that front - at least, outside of the relevant mailing lists - but the ext4 developers have not been idle. Some of their work has now come to the surface with Ted Ts’o’s posting of the ext4 merge plans for 2.6.25.
One of the changes going into ext4 is a lifting of the longstanding 4KB block size limit. That does not mean that just any block size works, though, and this feature will benefit fewer people than one might think, for one specific reason: the block size must still be no larger than the page size on the host system. So those of us running x86 systems with 4KB pages will be stuck with 4KB blocks still. And, on any system, the maximum block size is now 64KB.
One amusing effect of this change is that the size of a directory entry can now be as large as 64KB as well.