Re: [SSI] SSI vs. openMosix

[<mar...@pv...>]

Hello again,

I've now had the time to test SSI-linux on a two node cluster. Some
small quirkes during the install: In the INSTALL-doc, it should be
noted that it is assumed that the /-fs is the first line in /etc/fstab.
Otherwise, the addnode script fails.

It should also note that the first node must not have /boot on a
separate partition. Otherwise, the cluster_lilo script fails.

Quoting Bruce Walker <br...@ka...>:
>
> > > the absolute pathname for programs that should be migrated needs
> > > to be added to the /proc/cluster/loadlevellist file.
> > 
> > This sounds very cumbersome to ordinary users. If they compile
> > their own programs, their likely to have a different names each
> > time.
>
> The good news is that it is not too hard to revise the policy. 
> I'd like to leave it this way for awhile and gather more input on
> the most convenient mechanism.

I tried adding /usr/bin/sshd to the loadlevellist, but no joy.
I'm sorry to say that in the current setup, SSI-linux is not usable
to us, as our users have different names for their programs each time.
Also, I can't see any advantages of restricting migration to a defined
list of programs.

How hard would it be for me to change the behaviour to allow migration 
for all processes by default (perhaps restrict some daemons)?

> > > For example, if /usr/bin/make is added to the list then by 
> > > inheritance, all the children make forks will also be migratable.

While I haven't tested this with make, it is not true for sshd.

Having said those negative comments, I must say I like SSI (but only 
from an administrators point of view this far). We have just ordered 7
dual Xeon 1U servers from SuperMicro, and if the default migration 
issue is solved, they'll be running SSI-linux for sure. And if that 
should work out OK, we might even convert our present 8+4 node 
openMosix cluster to SSI-linux.


Regards,

Martin
-- 
"Computer science is not about computers any more than astronomy
is about telescopes." -- EW Dijkstra