On Wed, 2002-04-17 at 09:26, Richard Troy wrote: > > Here's my imperative: Every change to the structure on disk _must_be_ > written to disk that very instant. On-disk structure changes are _the_ > most critical aspect. Caching disk structure is fine, but having changes > in cache that are not yet reflected on disk is, OK, I'll say it: STUPID. "disk structure" = metadata Aren't all journalised filesystems doing exactly this? Ok, changes in metadata will not appear in the final place right from the beginning, but they _are_ written on disk immediately. They are just written in the journal instead of the actual metadata structures, but the information is moved from there later. But as long as they are on disk, it doesn't really matter where they actually are. In case of a failure, the journal is replayed and metadata ends up being written where it should. > Yes, I have even turned on sync, but from a performance standpoint, it's a > dumb way to go since _all_ data is written synchronously - it's only a > move of desperation. Still, for some of our more critical systems, sync is > left ON! That's how important this issue is. I certainly understand your concern. I did that too, back in the days of Ext2. > Please note that in my experience, ext3 doesn't work. When I upgraded my > systems from RH 6.2 to 7.2, I tried to tell it to use ext3, the default, > on several systems and each time was rewarded with a system that wouldn't > boot. (I don't recall just what the errors were, unfortunately.) If you're > going to propose an alternative file system, please give me some practical > advice about how I'm going to apply it. Looks like an installer problem, not a FS problem. I've seen that in the past, even when keeping the same FS. In the last couple of years, I ALWAYS avoid upgrades, and tell others to do the same. Instead, back-up everything, format, then install from scratch. Much safer this way. Also, much more work, but hey, if you go to such great lenghts as to turn SYNC on, you would certainly accept the extra effort of reinstalling from scratch. No to mention it's a good oportunity to clean up the system. -- Florin Andrei The ability to remember useless stuff is inversely related to the useful knowledge in one's head.
