The mechanism JBB for Windows uses for monitoring the file system requires allocating a buffer to place file system change notifications in.
The Journal daemon file system monitor uses to two threads for monitoring file system change activity - one thread for directory name changes (directory creations and deletions) and one thread for all other changes. The size of the notify buffers for these threads are specified by the NotifyBufferSize and DirNotifyBufferSize journal configuration settings. If notification are placed in the buffers faster than the file system monitor threads can process them a buffer overflow condition occurs and the journal must be reset since file system changes have been missed and the integrity of the journal has been compromised. Note that a singe file change may generate multiple change notifications, and each of these notifications will be placed in the notify buffer and must be processed. Typically buffer overflows when the file system changes rapidly over a short period of time, such as when where large directory trees are copied, deleted, or replicated. The system load in terms of CPU and memory utilization and the number of running processes can also influence the likelihood of buffer overflows as file system monitor threads will be preempted more and scheduled less on a heavily loaded system. In may cases the identical amount of file system change activity on a lighter loaded system won't cause buffer overflows which would occur on a more heavily loaded system. The mechanism file system monitoring mechanism JBB for Unix uses doesn't suffer this limitation and development is considering replacing the current Windows mechanism in a future release but there are no definite plans or commitments. Hope this helps ..... Pete Tanenhaus Tivoli Storage Manager Client Development email: [EMAIL PROTECTED] tieline: 320.8778, external: 607.754.4213 "Those who refuse to challenge authority are condemned to conform to it" ---------------------- Forwarded by Pete Tanenhaus/San Jose/IBM on 12/28/2006 11:34 AM --------------------------- Please respond to "ADSM: Dist Stor Manager" <[email protected]> Sent by: "ADSM: Dist Stor Manager" <[email protected]> To: [email protected] cc: Subject: Re: JBB Notification Buffer overflow ? On Dec 28, 2006, at 6:18 AM, Otto Chvosta wrote: > 12/28/2006 09:21:11 ReadFsChangesThread(tid 10236): > ReadDirectoryChangesW: > exiting thread due to buffer overflow error. You can research error messages... Search for "buffer overflow" at the TSM Support Page http://www-306.ibm.com/software/sysmgmt/products/support/ IBMTivoliStorageManager.html Richard Sims http://people.bu.edu/rbs/
