Mercurial > dovecot > original-hg > dovecot-1.2
changeset 1259:3be1497e09b9 HEAD
updated
author | Timo Sirainen <tss@iki.fi> |
---|---|
date | Wed, 26 Feb 2003 03:01:57 +0200 |
parents | 8672f9897066 |
children | e6e81ce8210b |
files | doc/nfs.txt |
diffstat | 1 files changed, 22 insertions(+), 8 deletions(-) [+] |
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--- a/doc/nfs.txt Wed Feb 26 01:12:55 2003 +0200 +++ b/doc/nfs.txt Wed Feb 26 03:01:57 2003 +0200 @@ -1,12 +1,10 @@ - - In general, we should be NFS-safe. - - - NFS server must support fcntl() locking currently. It's possible to - add file-based locking code, but I haven't bothered. +Indexe files aren't really NFS safe, and they likely won't be made. You can +access the actual mailboxes via NFS, but place the indexes into local hard +disk (see mail-storage.txt). - - Modifylog uses fcntl() for figuring out when to delete the log file, and - assumes that changing file locking between F_RDLCK / F_WRLCK is atomic - (not sure if this is the case with all operating systems, I hope so). - This anyway could be more difficult to change not to use fcntl(). + - .customflags and .subscriptions files require fcntl() locking currently. + Many NFS servers don't support it, at least without a separate lockd + daemon. I'll add optional support for .lock files later. - gethostname() must return different name for each IMAP server accessing a user's mailboxes @@ -16,3 +14,19 @@ new mail to get temporarily lost until more mail arrives. - One hour is enough to create a problem when two imap servers try to open the same mailbox at the same time. + +If you _really_ wish to try using indexes via NFS: + + - Indexes are shared mmap()ed and we rely on noticing changes made by others. + If your OS doesn't perform some magical mmap() updates (likely won't), + you'll need to modify the code so that each index update will update + sync_id in the header, and each time when index is accessed, the sync_id + should be read(). If it has changed, the file has to be re-mmap()ed. + + - Indexes require fcntl() locking. .lock files would be pretty slow, but + possible. + + - Modifylog uses fcntl() for figuring out when to delete the log file, and + assumes that changing file locking between F_RDLCK / F_WRLCK is atomic + (not sure if this is the case with all operating systems, I hope so). + This anyway would be more difficult to change not to use fcntl().