Those same metrics are still applicable for determining if you're 
running tight on physical memory.
Just because ZFS is in the mix as a memory consumer doesn't change the 
behavior of what
Solaris does when freemem drops below lotsfree - the page scanner still 
runs looking for
pages to free, so the "sr" column is vmstat will go non-zero.

anon page-ins and page-outs are also still an indicator.

What changes is accounting for ZFS as a memory consumer, since any low 
memory
situation requires accounting for memory use by the consumers - the 
kernel, file system
cache (which is also the kernel, but potentially a large enough consumer 
that it warrants
monitoring), and user processes.

memstat in mdb is a good place to start getting a high-level profile (as 
per Stefan's msg).

Check out www.solarisinternals.com for advice on capping the ZFS ARC 
cache if
you determine that ZFS is consuming memory at the expense of application
processes.

Thanks,
/jim


Stefan Parvu wrote:
> Dmitry Degrave wrote:
>   
>> In pre-ZFS era, we had observable parameters like scan rate and anonymous 
>> page-in/-out counters to discover situations when a system experiences a 
>> lack of physical memory. With ZFS, it's difficult to use mentioned 
>> parameters to figure out situations like that. Has someone any idea what we 
>> can use for the same purpose now ?
>>
>>     
>
> If I understood right, you are looking to see the amount of free 
> physical memory on a system running Solaris 10+. ZFS uses kernel memory 
> so you can easily check with mdb.
>
> Run mdb -k as root and at the command prompt try:
>
> ::memstat, like below:
>
> # mdb -k
> Loading modules: [ unix genunix specfs dtrace cpu.AuthenticAMD.15 uppc 
> pcplusmp scsi_vhci ufs ip hook neti sctp arp usba s1394 fctl nca lofs 
> zfs random md audiosup cpc fcp fcip crypto logindmux ptm sppp ipc nfs ]
>  > ::memstat
>
> Page Summary                Pages                MB  %Tot
> ------------     ----------------  ----------------  ----
> Kernel                     316214              1235   30%
> Anon                       373718              1459   36%
> Exec and libs               27512               107    3%
> Page cache                  28454               111    3%
> Free (cachelist)            50557               197    5%
> Free (freelist)            249959               976   24%
>
> Total                     1046414              4087
> Physical                  1046413
>
> there you will have a nice report about memory consumers.
>
>
> stefan
> _______________________________________________
> observability-discuss mailing list
> observability-discuss at opensolaris.org
>   

Reply via email to