> When this problem occurs, the hard-disk is usable as I can still copy files, move files, delete files etc. so I don't believe that it is an I/O issue. We are not currently tracking any I/O performance metrics.
>
> We do use UDFs, but they should not be affecting all connections. The strange thing is that the problem occurs about once a month.
>
> Nothing is logged in firebird.log.
>
> I'm guessing that there is some kind of issue in Super-Classic where it is doing some kind of internal process that blocks all database operations for a period of time. This problem was observed with both Firebird S.C. x64 2.5.0 and 2.5.1.

Beside Vlad's suggestion, you could also run fb_lock_print when the
system is under load.

Regards,
Thomas

> Regards,
>
> Anthony
>
> --- In firebird-support@yahoogroups.com, Dmitry Kuzmenko<kdv@...> wrote:
>> Looks like storage hangs. Have you looked at
>> - windows system log
>> - Perfmon, at the physical disk counters (queue, disk read bytes/sec,
>> disk writes bytes/sec)
>> ?
>>
>> and, anything in firebird.log?
>> do you use any UDFs?
>>
>> --
>> Dmitry Kuzmenko, www.ib-aid.com
>>
>
>
>
>
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