NVMe is not a hard disk

Re:NVMe is not a hard disk by ahupp on Friday June 11, 2021 @01:47PM (#27476379)

Not sure what to say, but this is how it works on all the large systems I'm familiar with.

Image you have two servers, each with two 1TB disks (4TB physical storage). And you have two distinct services with 1TB datasets, and want some storage redundancy.

One option is to put each pair of discs in a RAID-1 configuration, and so each RAID instance holds one dataset. This protects against a disk failure, but not against server or network failures.

Your other option is to put one copy of the dataset on each server. Now you are protected from the failure of any single disk, server, or the network to that server.

In both cases you have 2TB of logical storage available.

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Re:NVMe is not a hard disk by wafflespotato on Friday June 11, 2021 @04:32PM (#27478113)

you're putting yourself at risk of split-brain though (or downtime due to fail-over (or the lack of it)).

In either case what you're describing isn't really the 'cloud' alternative.

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Re:NVMe is not a hard disk by dan_quixote on Friday June 11, 2021 @05:05PM (#27478485)

Yeah, that's a complication/cost of HA that a significant portion of industry has long accepted. Everywhere I've been in the last 5 years has had this assumption baked in across all distributed systems.

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Re:NVMe is not a hard disk by nightfly on Friday June 11, 2021 @05:49PM (#27478918)

Where possible, my organization tries and have services deployed in sets of three (and try and require a quorum) to reduce/eliminate split-brain situations. And we're very small scale.

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