[Info-vax] free shell accounts?

[Jan-Erik Soderholm]

Stan Radford skrev den 2015-01-23 13:51:
> On 2015-01-22, Phillip Helbig (undress to reply) <helbig at asclothestro.multivax.de> wrote:
>> In article <m9r1cq$p2q$1 at speranza.aioe.org>, Stan Radford
>> <sradford at noemail.net> writes:
>>
>>> As long as they're all physically attached to the same drives. But if
>>> they're attached to network drives and the owning box goes down then there's
>>> a problem.
>>
>> Not if the disks the applications see consist of more than one physical
>> disk and/or connected to more than one node.
>
> If the file you want is on the portion of a volume that's only partially
> available now that the only owning box went down...

I think shadowing was ment here. In that case all volumes are
the same (has the same content) and the surviving mode will
simply go on running using the volume it still sees.

Whenever the other node come back up again, there will be a
"shadow copy" or "shadow merge" to sync the devices again.
A totaly transparent operation with only some additional
disk I/Os but to interuptions of other kind.


> However it is interesting that the rest of the volume or disk group
> or whatever it's called in VMS is still around.

Yes, in the case of shadowing. And it is called
"shadow set", the indivndual disks that makes up
one shadow disk, 6 maximum.

There is a kind striping available also, but that it not used
very much with todays disk capacities. But that will break if
one of the disk in the stripe-set failes (for any reason).


Jan-Erik.

>
> Stan
>