4 ms·
ZFS developers like to do this with hard drives :) But how did IBM do that with RAM? Do mainframes have… redundant RAM? Like literally sticks mirroring others?
by floatboth 8y ago
ZFS developers like to do this with hard drives :) But how did IBM do that with RAM? Do mainframes have… redundant RAM? Like literally sticks mirroring others?
- dralley 8y agoApparently, they can. https://en.wikipedia.org/wiki/Redundant_array_of_independent_memory https://en.wikipedia.org/wiki/Redundant_array_of_independent... But that was only introduced in 2010, so either the timeframe I was guessing at is wrong, or I'm misremembering what component it was. Could have been disk drives maybe.
- AnIdiotOnTheNet 8y agoSee [0] for an example of how people who are serious about fault tolerance design things. [0] https://en.wikipedia.org/wiki/Tandem_Computers https://en.wikipedia.org/wiki/Tandem_Computers
- krylon 8y agoI have seen one PC-based server that had redundant RAM. I never tried pulling out RAM modules, but I guess there is not much point in having a RAID1-like arrangement for RAM if the machine cannot handle random RAM modules dying without crashing the OS. And it wasn't even a super high-end system.
- forapurpose 8y ago> I have seen one PC-based server that had redundant RAM Yes, I've seen this too, and on lowish-end servers.
- snuxoll 8y agoMemory mirroring is a pretty common feature on basically every x86 server I've used (going back to the Core 2-based Xeon's, no experience with older platforms), though I've never tried just yanking DIMM's out and wouldn't recommend trying it.
- tolle 8y agoYes.
- rodgerd 8y agoYes. Doesn't help when your mainframe's infiniband controllers shit the bed and take the whole box down (a thing which has happened to me).