我有以下错误消息出现3连续的相同的邮箱
> (delivery failed to mailbox > /var/spool/postfix/vhosts/<user>/mail/inbox: > > unable to lock for exclusive access: Resource temporarily unavailable 我不明白发生了什么事。你能为我解释一下吗？
我能做些什么来避免这样的错误信息呢？
另外，我有以下设置：
# used only for creating mbox dotlock files when creation fails for INBOX. # Rely on O_EXCL to work when creating dotlock files. The default is to use # hard linking. O_EXCL makes the dotlocking faster, but it doesn't always #dotlock_use_excl = no # Locking method for index files. Alternatives are fcntl, flock and dotlock. # Dotlocking uses some tricks which may create more disk I/O than other locking # methods. NFS users: flock doesn't work, remember to change mmap_disable. #lock_method = fcntl # Which locking methods to use for locking mbox. There are four available: # dotlock: Create <mailbox>.lock file. This is the oldest and most NFS-safe # fcntl : Use this if possible. Works with NFS too if lockd is used. # flock : May not exist in all systems. Doesn't work with NFS. # lockf : May not exist in all systems. Doesn't work with NFS. # You can use multiple locking methods; if you do the order they're declared # in is important to avoid deadlocks if other MTAs/MUAs are using multiple # locking methods as well. Some operating systems don't allow using some of #mbox_read_locks = fcntl #mbox_write_locks = fcntl # Maximum time in seconds to wait for lock (all of them) before aborting. #mbox_lock_timeout = 300 # If dotlock exists but the mailbox isn't modified in any way, override the # lock file after this many seconds. #mbox_dotlock_change_timeout = 120 # Keep the mailbox locked for the entire POP3 session. #pop3_lock_session = no # blocking passdb and userdb queries (eg. MySQL and PAM). They're # [blocking=yes] [session=yes] [setcred=yes] # Setting blocking=yes uses the alternative way: dovecot-auth worker # [blocking=yes] - See userdb passwd for explanation # [blocking=yes] - See userdb passwd for explanation # [blocking=yes] - By default the lookups are done in the main dovecot-auth # proceses. Useful with remote NSS lookups that may block. # used either directly or though a dictionary server. The following dict block
这意味着postfix已经尝试同时向用户的邮箱传递四条消息。 至于你已经使用mbox作为邮箱格式，每个交付应按照操作顺序执行。 消息应该被存储，索引应该被更新，等等。 为了防止同时交付，可以打破mbox结构，每个交付首先尝试locking邮箱进行排他性操作。 之后的其他交付将看到该邮箱已被locking，并在当时不可能交付。 这就是为什么你在日志中看到三个警告 – 第一次交付已经locking邮箱，接下来三个失败。
没有发生危险。 当递送失败时， postfix推迟队列中的消息。 按时间排队的时间被处理，并且每个消息被再次递送。 导致来自队列的消息逐个传递，每次传递仅在前一个完成后才发生，日志文件中没有新的警告。 当然，如果因为某种原因再次发货失败，邮件将被放在队列中，并且会被logging下来。