[j-nsp] DRAM for M7 / crash of M7

[Jonathan Looney]

On Tue, Aug 26, 2008 at 6:33 AM, Matthias Gelbhardt <matthias at commy.de>wrote:

> I think this clearly states, that the 256 MB of memory are not enough. So
> we are now trying to upgrade it. I am surprised, that 600000 routes are
> obviously too much for this router. Will 786 MB do the trick also for a
> higher count of routes?
>

Here are my general thoughts on memory (not specific to Juniper):

1) Extra memory is one of the best ways to improve the performance of a slow
device, or maintain the performance of a fast device.  (There are limits to
this, but swapping can drag down performance in a hurry.)
2) Extra memory provides headroom for new services added to existing
devices.
3) Extra memory provides headroom for unexpected increases in the memory
requirements for existing services (sudden transient spike in the number of
received routes, sudden route churn, etc.).
4) New SW releases will almost always require more memory.  The amount of
memory seems to grow at an exponential, rather than linear rate, although
the rate certainly varies by OS (JUNOS would be closer to linear than
Windows, for example).

For all these reasons, I generally prefer to install double, triple, or
quadruple the amount of memory I think I need today.  (And, I try to do this
for everything: laptops, routers, firewalls, etc.)  In some cases, that has
come in very handy.  In others, it probably came in handy and I didn't even
notice.  And, that's kind of the point, isn't it? :-)

Memory is cheap insurance.

(Just my opinion...)

-Jon