(Illustration by Gaich Muramatsu)
On Wed, Jan 19, 2005 at 08:02:13PM +0500, Khalid Mehmood Khan wrote: > Pardon me if I sound a bit irrelevant, but after skimming through > coda's documentation and mailing list archives, I still find myself > somewhat sketchy regarding coda's implementation and hardware > requirements. I need to know: > > 1) Can we use some sort of a RAID for a coda server? (silly I guess) A Coda server is a normal userspace process, it stores metadata and file data in regular files on the local filesystem. There is no reason why RAID wouldn't work. > 2) Can I use coda for cyrus-imapd mail-boxes and configdirectory? Config directory definitely, I'm not sure about the mailboxes. Coda uses optimistic replication without locking, so there will be conflicts. But we only repair most types of directory conflicts automatically. So the best way to store email in Coda is in maildir format. Several of my mailboxes are stored in that format. If I am on a client that isn't running Coda (which doesn't happen often), I access them remotely through a courier-imap daemon which can handle maildir as the underlying storage. Another caveat with storing email in Coda in separate files is the limited directory size. With the typical file name lengths of maildir files we can only fit between 4000 and 5000 file names in a directory before it hits the 256KB boundary. So my linux-kernel mail still has to go to a folder on the local disk. Finally, when the mail-delivery process loses it's authentication tokens it cannot write to the email folders. For that I have my procmail scripts set up so that any failed mail goes into a 'retry-delivery' folder on the local disk. When I renew an expired token I run a script that feeds all the emails in that folder back through procmail so that they get redelivered in the right place. > 3) What hardware would be sufficient ( good) for a coda server? Not sure, our testserver ran for several years on a classic pentium 90 with only 64MB of memory or something like that. Ofcourse testserver was only infrequently accessed. Until last summer our main production servers were 200MHz PPro (or PII?) machines with 128-256MB of main memory. During the summer we replaced all machines with 3GHz P4's with gobs of memory. Comparitively they seem to be almost idle most of the time, but startup times are great. > 4) Is it necessary to have identical storage on SCM and non-SCM? I > mean if master is setup on a machine with three hard disks and > completely or partially replicated to some other machine, do we need > three hard disks on that machine too? Not really. If you want to keep everything replicated you might want to keep the amount of diskspace in the /vicepX partitions, which store the file data, roughly the same. JanReceived on 2005-01-21 11:56:22