(Illustration by Gaich Muramatsu)
shivers_at_cc.gatech.edu writes: > - Would coda have trouble with large filesystems, in the range 600Gb - 1.5Tb? > (E.g., a raid) There is a limit on RVM size, which holds metadata. So for moderate numbers of huge files it will be ok, but not huge numbers of moderate files (this is all per server). See the spiffy new 'rvmsizer' program in coda CVS. > rvmsizer /usr/ANONCVS/netbsd-1-6 9219 directories, 68400 files, 9622 directory pages total file size 476470597 bytes (454.40MB) average file size 6965 bytes total directory size 5288448 bytes (5.04MB) average directory size 573 bytes estimated RVM usage based on object counts, 37938188 bytes (36.18MB) estimated RVM usage based on 4% rule, 19270361 bytes (18.38MB) > - If I were to set up a coda server, and I was just as willing to run > Free/Net/OpenBsd or linux, is there a best candidate? I would run NetBSD. As a coda server, the real issue is 'anonymous rvm mapping', and I think that works better on BSD. But others can speak up and that may not be an issue any more. Aside from that, I think it's easier to deal with, more reliable, etc. but that doesn't have anything to do with coda. There is also the issue of the underlying fs for the coda files, and stability. I don't know about reiserfs, but I recall that with ext2fs the norm is to run async which means no ordered metadata updates. This is vulnerable to real trouble on power fail/crash, and I have heard stories that indicate this really happens. With BSD, you get synchronous metadata by default, and ordered metadata (softupdates) if you want. As long as your hw doesn't reorder writes (beware IDE, or check out write caching), big corruption should not happen. Plus, get a UPS for your server of course. There is a small minus that 1.6.2 doesn't have the 'realms' stuff in the kernel. -current does, and it's easy to patch the 1.6 seriies kernels. > + Were one to choose between lustre, coda & intermezzo, can anyone > give me a rough picture of the tradeoffs? My criteria are: > + private use, can't pay $$$ > + disconnected use over WAN > + replicated servers good > + clients for Win, BSD, linux & Mac good Coda works mostly ok, except that when you are write-disconncted over a thin pipe (28.8k) you will lose often with repair fake conflicts that require a full client reinit. The server is quite stable, but has limitations on sizes that are annoying but not crazy. > Perhaps this coda/intermezzo/lustre question is a politically charged > question of the sort that makes regular members of this mailing list roll > their eyes in a here-we-go-again sort of way, and if so, please excuse my > ignorance. I don't think this is the case. Basically no one here has played with it, I suspect. The problem with systems like this is that they require a significant investment to understand them and set them up. I've been running coda since 1997 or so, and would be inclined to play with intermezzo, but haven't had spare time or motivation. I also have the impression that it is mored tied to Linux. Being a BSD weenie, the lack of BSD support is a big drawback. -- Greg Troxel <gdt_at_ir.bbn.com>Received on 2004-01-14 16:08:24