Fwd: Tomcat6 port keeps locking up??
kayasaman at gmail.com
Fri Sep 17 11:12:00 UTC 2010
On 17/09/2010 13:07, Jeremy Chadwick wrote:
> On Fri, Sep 17, 2010 at 12:53:09PM +0300, Andriy Gapon wrote:
>> on 17/09/2010 12:42 Jeremy Chadwick said the following:
>>> On Fri, Sep 17, 2010 at 12:19:00PM +0300, Andriy Gapon wrote:
>>>> on 17/09/2010 11:56 Jeremy Chadwick said the following:
>>>>> I don't think you understand how Solaris's VM behaves with ZFS. It
>>>>> behaves very differently than FreeBSD. On Solaris/OpenSolaris with ZFS,
>>>>> you'll see the ARC taking up as much memory as possible -- but unlike
>>>>> FreeBSD (AFAIK), when a userland or kernel application requires more
>>>>> memory, the Solaris kernel dynamically releases portions of the ARC.
>>>> Can you please explain that "unlike" part?
>>> When ZFS was first introduced to FreeBSD, I was given the impression
>>> from continual posts on the mailing lists that memory which was
>>> allocated to the ARC was never released in the situation that a userland
>>> program wanted memory.
>>> An example scenario. These numbers are in no way accurate given many
>>> other things (network mbufs, UFS and VFS cache, etc.):
>>> - amd64 system has 2GB physical RAM (assume ~1920MB usable)
>>> - vm.kmem_size="1536M" + vfs.zfs.arc_max="1400M"
>>> - Heavy ZFS I/O results in ARC maxing out at ~1400MB
>>> - Userland application runs, requests malloc() of 1024MB
>>> - Userland gets 384MB from physical RAM, remaining 640MB from swap
>>> - ARC remains at 1400MB
>>> Is this no longer the case?
>> I am not sure if this has even been the case :-)
>> It is definitely not the case now.
> I trust your experience with it *much* more than mine. :-) It's very
> likely that I'm basing the "ARC remains at 1400MB" claim entirely off of
> what top(1) was showing under either "Inact" or "Wired".
> The terminology in top(1) for memory on BSD has always confused the hell
> out of me. That might sound crazy coming from someone that's been using
> *IX since 1990 and BSD since 1996, but it's true. The man page does go
> over what's what, but the descriptions are short one-liners (ex. "wired
> down" doesn't mean anything to me). This just circles back to my lack
> of knowledge about the VM.
Aren't there supposed to be 2 versions of 'top'??
Unix top and Linux top??
Both with slightly different handles on the representation of information?
I just recall reading somewhere!!
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