uninterruptible sleep

[Roger Oberholtzer]

On Mon, 2007-01-08 at 13:36 +0200, Dirk Moolman wrote:

> I see what you mean, thanks.   To find these processes, will ps -aux be
> sufficient ?    I tried this, and then ran an strace on one of these
> pid's.
> They all seem to belong to our Oracle database (they are probably
> database processes which are handled by Oracle itself)  - this probably
> means I will have to do some performance monitoring within our Oracle
> system.

Oracle probably accesses the databases via a class of functions
specifically for async I/O. Such access is one of the things that Oracle
seems to require if it is going to support a given os.

> The processes also don't seem to hang anywhere (if I am interpreting
> strace correct) - if they do, it must happen in fractions of a second,
> which I won't notice, but the opsys does.

You can tell strace to print the time spent in each system call (e.g.,
-T). From that you might deduce if much time is in blocking system
calls.

> Do you think this could be normal, and just the way Oracle behaves on a
> busy system ?

No idea.

-- 
Roger Oberholtzer

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