zfs discuss - Apr 2010 - [install-discuss] Installing Opensolaris without ZFS?

I doubt it. ZFS is meant to be used for large systems, in which memory is not an
issue

Best regards

roy
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----- "????? ????????????" <olga.kryzhanovska at gmail.com>
skrev:
> Are there plans to reduce the memory usage of ZFS in the near future?
> 
> Olga
> 
> 2010/4/2 Alan Coopersmith <alan.coopersmith at oracle.com>:
> > ????? ???????????? wrote:
> >> Does Opensolaris have an option to install without ZFS, i.e. use
> UFS
> >> for root like SXCE did?
> >
> > No.  beadm & pkg image-update rely on ZFS functionality for the
root
> > filesystem.
> >
> > --
> >        -Alan Coopersmith-        alan.coopersmith at oracle.com
> >         Oracle Solaris Platform Engineering: X Window System
> >
> >
> 
> 
> 
> --
>       ,   _                                    _   ,
>      { \/`o;====-    Olga Kryzhanovska   -====;o`\/ }
> .----''-/`-/     olga.kryzhanovska at gmail.com  
\-`\-''----.
>  `''-..-| /     Solaris/BSD//C/C++ programmer   \ |-..-''`
>       /\/\                                     /\/\
>       `--`                                      `--`
> _______________________________________________
> zfs-discuss mailing list
> zfs-discuss at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

Are there plans to reduce the memory usage of ZFS in the near future?

Olga

2010/4/2 Alan Coopersmith <alan.coopersmith at
oracle.com>:
> ????? ???????????? wrote:
>> Does Opensolaris have an option to install without ZFS, i.e. use UFS
>> for root like SXCE did?
>
> No.  beadm & pkg image-update rely on ZFS functionality for the root
> filesystem.
>
> --
>        -Alan Coopersmith-        alan.coopersmith at oracle.com
>         Oracle Solaris Platform Engineering: X Window System
>
>


-- 
      ,   _                                    _   ,
     { \/`o;====-    Olga Kryzhanovska   -====;o`\/ }
.----''-/`-/     olga.kryzhanovska at gmail.com   \-`\-''----.
 `''-..-| /     Solaris/BSD//C/C++ programmer   \ |-..-''`
      /\/\                                     /\/\
      `--`                                      `--`

[removing all lists except ZFS-discuss, as this is really pertinent only 
there]

????? ???????????? wrote:
> Are there plans to reduce the memory usage of ZFS in the near future?
>
> Olga
>
> 2010/4/2 Alan Coopersmith <alan.coopersmith at oracle.com>:
>   
>> ????? ???????????? wrote:
>>     
>>> Does Opensolaris have an option to install without ZFS, i.e. use
UFS
>>> for root like SXCE did?
>>>       
>> No.  beadm & pkg image-update rely on ZFS functionality for the
root
>> filesystem.
>>
>> --
>>        -Alan Coopersmith-        alan.coopersmith at oracle.com
>>         Oracle Solaris Platform Engineering: X Window System
>>     
The vast majority of ZFS memory consumption is for caching, which can be 
manually reduced if it''s impinging on your application. See the tuning 
guide for more info:

http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide

As pointed out elsewhere, these tuning parameters are generally for 
highwater marks - ZFS will return RAM back to the system if it''s needed
for applications. So, in your original problem, the likelihood is /not/ 
that ZFS is consuming RAM and not releasing it, but rather than your 
other apps are overloading the system.


That said, there are certain minimum allocations that can''t be reduced 
and must be held in RAM, but they''re not generally significant.
UFS''s
memory usage is really not measurably different than ZFS''s, so far as I
can measure from a kernel standpoint.  It''s all the caching that makes 
ZFS look like a RAM pig.

One thing though:  taking away all of ZFS''s caching hurts performance 
more than removing all of UFS''s file cache, because ZFS stores more
than
simple data in it''s filecache (ARC).

Realistically speaking, I can''t see running ZFS on a machine with less 
than 1GB of RAM.  I also can''t see modifying ZFS to work well in such 
circumstances, as (a) ZFS isn''t targeted at such limited platforms and 
(b) you''d seriously compromise a major chunk of performance trying to 
make it fit. These days, 4GB is really more of a minimum for a 64-bit 
machine/OS in any case.

I certainly would be interested in seeing what a large L2ARC cache would 
mean for reduction in RAM footprint;  on one hand, having an L2ARC 
requires ARC (i.e. DRAM) allocations for each entry in the L2ARC, but on 
the other hand, it would reduce/eliminate storage of actual data and 
metadata in DRAM.

Anyone up for running tests for a box with say 512MB of RAM and a 10GB+ 
L2ARC (in say an SSD)?

-- 
Erik Trimble
Java System Support
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Phone:  x17195
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