Re: [PLUG] Pros and cons of swap in a partition vs. in a file in the file system

[Jeff McAdams <jeffm@iglou.com>]

David Colon wrote:
>> We've done this where I work, on occasion.  We have some commercial apps
>> (aren't they always the problem children?) that insist on having x
>> amount of swap space available on the system, regardless of whether
>> there's ever any real chance of even touching it.  So we use dd to
>> create a big file of the size needed, mkswap it, and swapon it at a
>> priority level that it'll never get used.  Badly behaved commercial apps
>> are happy, and the only thing we're out is some disk space that'll never
>> get touched.  Shoot...if you can swing a way to create the file as a
>> sparse file, there's a pretty good chance that most of that disk space
>> will never actually get allocated anyway!

>      Ugh, Oracle is such a commercial app.

That would be the one I was thinking of, yes.  :)

> On a machine with 16 gigs
> of RAM, the installer won't run if you don't have 16 or 32 gigs of
> swap.  Oracle support is the same way.  We have machines that had
> Oracle installed when the machine had  8 gigs of RAM and swap.  We
> later upgraded the machine to 16 gigs of RAM and left the swap as is
> because it was never used.  Recently, our DBAs had to open a case with
> Oracle because one of the databases kept crashing.  Oracle blamed the
> crashes on the fact that there wasn't enough swap even though sysstat
> and other output showed that swap was never being used.  I created a
> swap file to bring the total up to 16 gigs and the crashes continued.
> I'm waiting to hear their next response.

And that sounds about like what I would expect from Oracle support as well.

-- 
Jeff McAdams
"They that can give up essential liberty to obtain a
little temporary safety deserve neither liberty nor safety."
                                       -- Benjamin Franklin

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