On Fri, Jun 09, 2006 at 10:11:59PM -0400, Jeff Garzik wrote: > Trivial to prove false, by your statement above if nothing else. But > anyway: > Run mke2fs on a blkdev of size 500MB, and one of 500GB. Note values. > Now resize blkdev formatted for size 500MB to 500GB, and note differences. OK, so *that's* what you were trying to get at. I wish you had said that from the first, since most people who are creating filesystems to resize (i.e., on LVM or RAID systems), don't start them as small as 500MB. Yes, the default inode ratio and blocksize is different for filesystems under 512MB. But that's largely irrelevant for the use cases of online resizing, where people will generally be starting with a filesystem *far* larger than 512megs. They might starting with an LVM sized to be 2 gigs and resize it to 5 gigs. Or 100 gigs and resizing it 200 gigs; or 500gigs; or a terrabyte. In all of those cases, the results are identical. It also by the way has nothing to do with the "inode allocation algorithm", as you caleimd. The biggest difference will come from the use of a 1k blocksize instead of 4k blocksize, but that's a matter of the defaults that were selected for "small" filesystems. If someone was creating a file system that they knew they were likely to resize to 500GB, they could always create it with an explicitly specified blocksize of 4k, and also specify a different inode ratio. And this is your argument that on-line resizing is a horrible hack, and ext3 should be thrown out and rewritten from scratch? That's weak. One other thought --- people do *care* about backwards compatibility from a filesystem format level, and they do appreciate being able to easily upgrade and take advantage of new filesystem features without needing to do a dump/restore. If you don't care about compatibility, but want a scalable filesystem, take a look at JFS. It's very, very, good at what it does (and has support for extents and large block numbers) --- and it's smaller than XFS and doesn't have the VNODE and System V/IRIX API compatibility crud of XFS. The only downside with it is that you do have to do a backup, reformat, and restore, and of course, the lack of support from pretty much all of the major distributions. - Ted - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
