Hi;
I've just went through the following URL
http://blogs.sun.com/roller/page/roch?entry=the_dynamics_of_zfs
For those interested, I got to the above URL from
http://www.solarisinternals.com/wiki/index.php/Solaris_Internals_and_Performance_FAQ
Under the section ("DOES ZFS REALLY USE MORE RAM ?"), he clearly
elaborated ZFS's memory requirements.
For the offtopic query "How can ZFS require more VM address space but
not more VM ?", my simple explanation (which may be wrong) would be
That Solaris VM immediately "reserves" swap space upon memory request.
This takes place even though no actual physical page (and also VM page?)
is yet assigned to the malloc call. It was made very clear in the first
Edition of Solaris Internals that Solaris avoids the "lazy" method of
memory assignment used by AIX and Linux (which may result in things like
OOM described clearly in http://lwn.net/Articles/104179/
Am I right? Or completely off course?
Warmest Regards
Steven Sim
Pramod Batni wrote:
Darren J Moffat wrote:
Steven Sim wrote:
Casper;
Does this mean it would be a good practice to say increase the
amount of memory and/or swap space we usually recommend if the
customer intends to use ZFS very heavily?
ZFS doesn't necessarily use more memory (physical or virtual) than
UFS it needs more VM *address space* (not the same as more VM) hence
the 64 bit processor.
offtopic query :
How can ZFS require more VM address space but not more VM ?
thanks.
Pramod
Fujitsu Asia Pte. Ltd.
_____________________________________________________
This e-mail is confidential and may also be privileged. If you are not the intended recipient, please notify us immediately. You should not copy or use it for any purpose, nor disclose its contents to any other person.
Opinions, conclusions and other information in this message that do not relate
to the official business of my firm shall be understood as neither given nor
endorsed by it.
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
