On Sat, Jul 18, 2009 at 02:52:13AM -0400, Andreas Dilger wrote: > If you aren't running a 32-bit system with this config, you shouldn't > really care. For those systems that need to run in this mode they > would rather have it work a few percent slower instead of not at all. Well, it doesn't work at all anyways due to the fsck problem. > The last test numbers I saw were 5GB of RAM for a 20TB filesystem, > but since the bitmaps used are fully-allocated arrays that isn't > surprising. We are planning to replace this with a tree, since the > majority of bitmaps used by e2fsck have large contiguous ranges of > set or unset bits and can be represented much more efficiently. You would need to get <~2.5GB for 32bit. In practice that's the limit you have there. > Also, for filesystems like btrfs or ZFS the checking can be done > online and incrementally without storing a full representation of > the state in memory. You could, but I suspect it would be cheaper to just use a 64bit system than to rewrite fsck. 64bit is available for a lot of embedded setups these days too. -Andi -- ak@xxxxxxxxxxxxxxx -- Speaking for myself only. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
