3 ms·

Don't look into BSD, you gotta look at mainframes. Some of the mainframes at banks have been running since they bought the very first one in the 90s or even 80s

by zaarn 7y ago

Don't look into BSD, you gotta look at mainframes. Some of the mainframes at banks have been running since they bought the very first one in the 90s or even 80s. Since stuff like VMS allowed to simply clustering, you could simply add modern machines, transfer over and shutdown the old hardware without having to shutdown the system itself. These are probably the only machines with a chance to reach 30+ years of uptime.

dogma1138 7y ago
Many if not all of these mainframes have been fully upgraded or at least serviced due to hardware failure while still running. I’m not entirely sure how you define uptime for these machines if none of the original parts are still there.
- pinkfoot 7y ago
  Trivially: 100%
- verisimilitude 7y ago
  Philosophers ask a similar question to yours: https://en.wikipedia.org/wiki/Ship_of_Theseus https://en.wikipedia.org/wiki/Ship_of_Theseus
  - dogma1138 7y ago
    I was hinting at that, which is why we should define an uptime of a system rather than a machine because with distributed systems that uptime of the system isn't dependent on the uptime of a single "machine" and a mainframe is a distributed system even if it's in a single rack. The question is then where you define the boundaries of a system and it's uptime. At least from my recollection for mainframes they defined uptime based on the execution of batch jobs and availability of services not the OS/Hardware which if it crashed often involved Big Blue coming to investigate WTF happened and how it happened since System Z machines are designed with so much redundancy that you can swam RAM modules without interrupting the workflow. Today with RAIM (RAID for Memory) IBM System Z machines even support an entire memory channel dying without interruption.
zamadatix 7y ago
But the topic is safe uptime for a computer connected to the internet. I have no doubt a mainframe has a chance to reach 30+ years of lifetime but I also have no doubt it'd also be done for if attacked.
giancarlostoro 7y ago
Dont forget some of those systems are highly firewalled to middle-men who then send back data to the web or other UIs.

by zaarn 7y ago

dogma1138 7y ago

Many if not all of these mainframes have been fully upgraded or at least serviced due to hardware failure while still running. I’m not entirely sure how you define uptime for these machines if none of the original parts are still there.

pinkfoot 7y ago
Trivially: 100%
verisimilitude 7y ago
Philosophers ask a similar question to yours: https://en.wikipedia.org/wiki/Ship_of_Theseus https://en.wikipedia.org/wiki/Ship_of_Theseus
- dogma1138 7y ago
  I was hinting at that, which is why we should define an uptime of a system rather than a machine because with distributed systems that uptime of the system isn't dependent on the uptime of a single "machine" and a mainframe is a distributed system even if it's in a single rack. The question is then where you define the boundaries of a system and it's uptime. At least from my recollection for mainframes they defined uptime based on the execution of batch jobs and availability of services not the OS/Hardware which if it crashed often involved Big Blue coming to investigate WTF happened and how it happened since System Z machines are designed with so much redundancy that you can swam RAM modules without interrupting the workflow. Today with RAIM (RAID for Memory) IBM System Z machines even support an entire memory channel dying without interruption.

zamadatix 7y ago

But the topic is safe uptime for a computer connected to the internet. I have no doubt a mainframe has a chance to reach 30+ years of lifetime but I also have no doubt it'd also be done for if attacked.

giancarlostoro 7y ago

Dont forget some of those systems are highly firewalled to middle-men who then send back data to the web or other UIs.