Jason Bradfield wrote:
Sorry if this comes through as a duplicate response but I responded from
a different email account earlier...
Thanks Bob and Jeff...
Therefore here is my confusion..
From Bob
* swap: the amount of disk space set aside to copy physical memory to
when copying it out of RAM
From Jeff
set swap= this is VM - the total address space available to the zone
Ok.. to solve my immediate problem 16GB Physical and 16GB disk = total
of 32GB Virtual
If I were to create 3 zones and wanted to evenly allocate memory to all
3 and the global zone, would this config be ok
zonecfg:host30> add capped-memory
zonecfg:host30:capped-memory> set physical=4G
zonecfg:host30:capped-memory> set swap=8G
zonecfg:host30:capped-memory> end
Memory capping isn't really intended to solve the 'problem' of allocating
memory, because usually there isn't a problem. Memory capping is intended to
prevent memory hogs (accidental or otherwise) from impacting proper operation
of other workloads. This allows you to choose large caps, improving resource
usage efficiency.
With some v12n solutions, allocating memory is required. This has the
potential of wasting memory - if one virtual server is not using all of its
memory, another cannot.
With zones, memory allocation (and its wastefulness) is not necessary.
Further, choosing a physical memory cap that is too low will result in
unnecessary paging activity, which will significantly reduce performance on
that one zone, and also affect performance of other zones, to some extent.
However, if you want to ensure that one zone does not use too much and impact
other zones, measure (or estimate) its normal memory usage, and choose a value
larger than that. After the zone is running, "prstat -Z" can be used to
measure memory usage, both physical and swap.
With all of that in mind, in your situation I would choose much larger numbers
than the ones shown above. But without understanding the normal resource
consumption of your workloads, I can't guess at good values.
Finally, it usually helps to know that those caps can be changed while the
zone is running, using rcapadm from the global zone.
Thanks.
Bob Bownes wrote:
>> Can anyone, in lamens (ex linux) terms explain the differences between
>> virtual/swap/rss/size/physical etc or recomend a good
>> blog/article/document.
>
>I don't know Linux terms, so I'll define terms for this conversation:
>* physical memory: RAM, memory chips
>* VM (virtual memory): the total memory space available, both in RAM and
> on disk
>
I'll add:
* swap: the amount of disk space set aside to copy physical memory to
when copying it out of RAM
* rss: Resident Set Size - the part of a process address space which
is currently resident in RAM
* size: The total address space used by a process
* physical - various definitions, most common one i've seen is the
total amount of RAM in the system. Also refered to as 'real' in some
places
And a link I found that might be of some use:
http://www.memorymanagement.org/
>The terms in zonecfg are:
>* set physical= this is what I am calling "physical memory"
>* set swap= this is VM - the total address space available to
the zone
>
>So if you want to limit the zone's processes to 384MB of VM and 128MB
of RAM, use:
>
>add capped-memory
>set physical=128m
>set swap=384m
>end
>If you already have added these, you must use "select capped-memory"
instead
>of "add capped-memory".
>
>
>Does that help?
--
--------------------------------------------------------------------------
Jeff VICTOR Sun Microsystems jeff.victor @ sun.com
OS Ambassador Sr. Technical Specialist
Solaris 10 Zones FAQ: http://www.opensolaris.org/os/community/zones/faq
--------------------------------------------------------------------------
_______________________________________________
zones-discuss mailing list
zones-discuss@opensolaris.org
