[Gllug] Cloning only one of two partitions & how necessary is swapspace...

[John Edwards]

On Sun, Apr 11, 2010 at 03:53:22PM +0100, general_email at technicalbloke.com wrote:
<snip>
>> Munin is a general performance monitor system that produces web
>> pages and graphs, and includes both swap usage and I/O. It's very
>> simple to setup.
>>
> 
> Thanks John,
> 
> I was heartened to see this app is included in the Ubuntu repos and
> started setting it up but, although I'm sure you are correct that it is
> very simple for what it is, I balked when I came across the 18 page how
> to. I think this may be overkill for what I want, namely a simple count
> of how many blocks are written to the swapfile over 24 hours.

The Debian/Ubuntu packages do a good default install that just
monitors localhost and automatically runs munin-node-configure
to give you a reasonable set of .

If you want to monitor other systems then you add an "allow" line
to /etc/munin/munin-node.conf on each node machine, and add each
node to /etc/munin/munin.conf on the monitoring server.


> I'm sure something like systemtap or dtrace could tell me this but they
> look pretty involved too. Is there nothing simpler that can monitor swap io?
> 
> I was hoping there would be a bash one liner or some combination of
> switches for iotop that would give me this info, or at least create a
> log that I could extract it from with a little scripting (in a language
> I know).

Have a look at sar (part of sysstat), atsar, or atop. These are all
activity monitors that have command line only tools.

If you want to use sar from the sysstat package on Debian/Ubuntu then
you will need to enable sadc in /etc/default/sysstat. There is not
much else you need to configure to get them to start, but you will
need read to the man pages carefully in order to get the info you
want displayed.


Here is an example output from 'atsar -p':
--------
00:00:01   pagein/s pageout/s     swapin/s swapout/s         fork/s
00:10:01       0.07    285.99         0.00      0.00           5.01
00:20:01       0.07     72.65         0.00      0.00           1.92
00:30:01       0.06     66.31         0.00      0.00           1.85
00:40:01       0.03     77.63         0.00      0.00           1.94
00:50:02       0.07     83.83         0.00      0.00           1.93
01:00:01       0.09     87.23         0.00      0.00           1.81
01:10:02       0.08    296.51         0.00      0.00           5.04
01:20:01    4750.55    122.64         0.00      0.00           1.90
01:30:01       0.18     70.01         0.00      0.00           1.88
--------



-- 
#---------------------------------------------------------#
|    John Edwards   Email: john at cornerstonelinux.co.uk    |
#---------------------------------------------------------#
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 204 bytes
Desc: Digital signature
URL: <http://mailman.lug.org.uk/pipermail/gllug/attachments/20100411/88e9580a/attachment.pgp>
-------------- next part --------------
-- 
Gllug mailing list  -  Gllug at gllug.org.uk
http://lists.gllug.org.uk/mailman/listinfo/gllug