Here is a bit more feedback. (1) Due to the need to respond within 45 seconds to any CIFS request with either success or failure, the RX timeout values on the Windows client are very short when compared to the UNIX AFS clients. If there are network congestion issues, packet loss, or large amounts of latency this can contribute to delays in responding promptly to the CIFS client. Failure to respond within 45 seconds will result in the CIFS client breaking the virtual circuit with the AFS cache manager. If overlapped I/O is being used, a delayed write error message will be displayed by the system process.
(2) When compiling code out of AFS using the Windows client, try to minimize the use of INCLUDE search paths, or Java CLASSPATH search paths that include paths within AFS. The AFS directory structure uses case sensitive hash tables to speed the access to directory entries. The hash tables are useless on Windows because Windows treats file names without case sensitivity. Multiple entries that differ only by case must be detected by the Windows client. The behavior of the IBM AFS client was particularly dangerous in that if you said "DEL foo" and there were two entries "Foo" and "FOO" both would be deleted. If you said "TYPE foo" and "Foo" and "FOO" existed, you would get the one listed first in the directory. First in the directory does not mean the one created first but simply the one that is discovered first. Without the hash tables, directory searches are linear scans of all directory entries. This is very CPU intensive and time consuming to perform repeatedly. (3) If you have a router that does not maintain port mappings for UDP sessions, there will be long delays with the file and volume servers. I have a Netopia 4686XL v8.6.1r4 router. When the Stateful Packet Inspection is disabled it uses an extremely short inactivity timeout (< two minutes) which causes AFS significant problems. Whenever there is a pause in access to a particular AFS server the port mapping changes causing the AFS server to treat the connection as new. To do otherwise would open AFS to connection hijacking. When Stateful Packet Inspection is enabled and the UDP inactivity timeout set beyond ten minutes, the performance of AFS is exceptional. --- In summary, the OpenAFS Windows client is very sensitive to the network performance. If you are having issues, the behavior of the network is a good place to start looking. Jeffrey Altman Secure Endpoints Inc.
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