On Sun, Nov 11, 2012 at 04:55:12AM -0500, George Spelvin wrote: > Now, it turns out that I have to rebuild it with 64-bit block numbers > in order to grow it past 16 TB (wow, was *that* a nasty surprise), > and I intend to use a somewhat saner bytes/inode ratio. > > (Ignoring the slight space gain, fewer inodes means faster e2fsck.) Actually, with ext4, we keep track of the last used inode in each block group, so there isn't a speed gain for using a smaller number of inodes. It did make a difference for ext3, but not for ext4. > I could just use that, so the FS will run out of data blocks at about > the same time as it runs out of inodes, but I wonder: does the FS benefit > from more slack in inode allocation? The file system doesn't actually gain anything one way or another in terms of slack space in the inode table. The major downside is that if you guess wrong, and you have many more smaller files than you had estimated, there's no way to change the inode ratio afterwards, sort of backing up and reformatting. So that's why historically we've tended to massively overprivision the number of inodes available to the file system. Regards, - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
