Hi,

Thank you for that details :-)

Thats the reason why I asked for the actual jbbtools.
We've got our version from IBM support a jear ago.

We used the filemon tool to find out the right size of our notification
buffers.
In filemon.exe in our version there is only one option for the buffer size
(NotifyBuffer) but no one for directory change notification.

I did some tests with filemon using different filters (fn only, fd only ...
Each filter type only) and different buffer sizes on different domains with
ever same effect -> overflow

System load on the server is very low at the moment (Xmas holidays 80% Idle)

Client OS is a Microsoft Storage Server 2003 R2 ...

Is it possible that the Microsoft Managment Console/Storage Managment with
it's 'Shared Folder Extension' installed on the client is the reason for the
curious behavior of the notification mechanism ?

Do you know if there is a newer version of the jbbtools available und where
can we get them ?

Thanks for your efforts,

Otto Chvosta
_____________________________________
TSM-Administration
Medical University of Vienna, Austria

 


-----Ursprüngliche Nachricht-----
Von: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] Im Auftrag von
Pete Tanenhaus
Gesendet: Donnerstag, 28. Dezember 2006 17:55
An: ADSM-L AT VM.MARIST DOT EDU
Betreff: [ADSM-L] Fw: JBB Notification Buffer overflow ?

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: tanenhau AT us.ibm DOT com
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" <ADSM-L AT VM.MARIST DOT EDU>
Sent by:        "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
To:     ADSM-L AT VM.MARIST DOT EDU
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/