PDT/paging space questions

PDT/paging space questions

Post by Scott Hammo » Sat, 11 Aug 2001 21:54:56



Hello Everyone,

I am running PDT on my AIX 4.3.3 boxes, and getting some reports back
with the following messages:

  VIRTUAL MEMORY
   -  VMM has identified 49 bad frames

  -  Paging space hd6 on volume group rootvg is fragmented

What does the "49 bad frames" message refer to, and what corrective
action can I take?

And how can I un-fragment a paging space?  Can I use defragfs, and can
I do it with the system running.

Thanks for the info,

Scott

 
 
 

PDT/paging space questions

Post by Chris Snyder » Tue, 14 Aug 2001 08:20:00


It seems the only way to defrag the paging space is a reboot. On
recommendation of IBM we reboot our servers once a week to address the
paging space growth issue. Best is to see how it grows by using lsps -s and
set a reboot frequency according to the results.obtained over a period of
time.

Any other suggestions anyone?


Quote:> Hello Everyone,

> I am running PDT on my AIX 4.3.3 boxes, and getting some reports back
> with the following messages:

>   VIRTUAL MEMORY
>    -  VMM has identified 49 bad frames

>   -  Paging space hd6 on volume group rootvg is fragmented

> What does the "49 bad frames" message refer to, and what corrective
> action can I take?

> And how can I un-fragment a paging space?  Can I use defragfs, and can
> I do it with the system running.

> Thanks for the info,

> Scott


 
 
 

PDT/paging space questions

Post by Jose Pina Coelh » Wed, 15 Aug 2001 10:43:12



Quote:> It seems the only way to defrag the paging space is a reboot. On
> recommendation of IBM we reboot our servers once a week to address the
> paging space growth issue. Best is to see how it grows by using lsps -s
and
> set a reboot frequency according to the results.obtained over a period of
> time.

> Any other suggestions anyone?

Yes, find the program that is eating up memory.  Get the vendor to fix it.
If it's not a program, it's the OS, so get IBM to fix it.



> > Hello Everyone,

> > I am running PDT on my AIX 4.3.3 boxes, and getting some reports back
> > with the following messages:

> >   VIRTUAL MEMORY
> >    -  VMM has identified 49 bad frames

> >   -  Paging space hd6 on volume group rootvg is fragmented

> > What does the "49 bad frames" message refer to, and what corrective
> > action can I take

man pdtreport ?

Quote:> > And how can I un-fragment a paging space?  Can I use defragfs, and can
> > I do it with the system running.

#1 - The paging space is not a filesystem.
#2 - It means that hd6 is fragmented at the LVM level (i.e. LP's scattered
        instead of contiguous).
so reorgvg

Also:
-  Never have more than one paging space per disk.
-  A paging space should be made of contiguous PP's.
-  If you have a VG with two paging spaces (one on each disk) and
   decide to mirror the vg, don't forget to remove one of the paging spaces.

--
Doing AIX support was the most monty-pythonesque
activity available at the time.

 
 
 

1. Paging space size (NOT swap space size)

Linux device/file is a paging file, Linux does not swap processes out to
disk [slow 386 I/O on AT bus would cause swapping to take longer than
reading process from orig exec].

The BSD rule for swapping size DOES NOT APPLY.

SunOS uses both swapping and paging [SUNOS 3.x was about 4 times as fast
as present 4.x OS --- of course SUN is selling SPARC 4 vice SUN 2 or SUN
3 hardware]

For Linux:  Add actual memory and swap (really paging) space for maximum
you need.  Personally, I have 8 MB memory and overkill on paging file of
10 MB.  I think top(1) or something can monitor amount of paging used.
Luckily, we don't thrash like SunOS so don't need as good a utility to
monitor swapping and paging.

John

2. Diamond Viper Pro HELP!

3. VMWare = Swap space on Host Linux and paging space for Guest OS

4. Problem with Logs

5. Paging space & File System space

6. SCCS question

7. memory space vs page space

8. Appletalk through a Linux Router

9. heap space vs. paging space (what does free() do?)

10. Resizing space of paging space

11. PDT question

12. Question about PDT error message