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SSDs have become fast, except in the cloud

databasearchitects.blogspot.com

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Re: SSDs have become fast, except in the cloud

#271

Post by e12e »

Twirrim wrote: post #57

Disclaimer: I work for OCI, opinion my own etc. We offer faster NVMe drives in instances. Our E4 Dense shapes ship with SAMSUNG MZWLJ7T6HALA-00AU3, which supports Sequential Reads of 7000 MB/s, and Sequential Write 3800 MB/s. From a general perspective, I would say the _likely_ answer to why AWS doesn't have faster NVMes at the moment is likely to be lack of specific demand. That's a guess, but that's generally how t…

> I work for OCI

Ah: Oracle cloud infra

https://blogs.oracle.com/cloud-infrastructure/post/announcin...

I keep forgetting Oracle is in the cloud business too.

"Make it rain", I guess :)

Re: SSDs have become fast, except in the cloud

#272

Post by karmakaze »

jsnell wrote: post #28
pclmulqdq wrote: post #11

This was a huge technical problem I worked on at Google, and is sort of fundamental to a cloud. I believe this is actually a big deal that drives peoples' technology directions. SSDs in the cloud are attached over a network, and fundamentally have to be. The problem is that this network is so large and slow that it can't give you anywhere near the performance of a local SSD. This wasn't a problem for hard drives, whi…

According to the submitted article, the numbers are from AWS instance types where the SSD is "physically attached" to the host, not about SSD-backed NAS solutions. Also, the article isn't just about SSDs being no faster than a network. It's about SSDs being two orders of magnitude slower than datacenter networks.

I've run CI/CD pipelines on EC2 machines with local storage, typically running Raid-0, btrfs, noaccestime. I didn't care if the filesystem got corrupt or whatever, I had a script that would rebuild it in under 30mins. In addition to the performance you're not paying by IOPs.

Re: SSDs have become fast, except in the cloud

#273

Post by mr_toad »

manquer wrote: post #112
rfoo wrote: post #86

Earlier quoted context omitted.

Why would I lose all data on these SSDs when I initiate a power off of the VM on console, then? I believe local SSDs are definitely attached to the host. They are just not exposed via NVMe ZNS hence the performance hit.

It is because on reboot you may not get the same physical server . They are not rebooting the physical server for you , just the VM Same VM is not allocated for a variety of reasons , scheduled maintenance, proximity to other hosts on the vpc , balancing quiet and noisy neighbors so on. It is not that the disk will always wiped , sometimes the data is still there on reboot just that there is no guarantee allowing the…

Data persists between reboots, but not shutdowns:

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-inst...

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-inst...

Re: SSDs have become fast, except in the cloud

#276

Post by zokier »

bombcar wrote: post #84
_Rabs_ wrote: post #8

Earlier quoted context omitted.

Sure, but it does make me wonder what kind of speeds we are paying for if we can't even get raw hardware speeds... Sounds like one more excuse for AWS to obfuscate any meaning in their billing structure and take control of the narrative. How much are they getting away with by virtualization. (Think how banks use your money for loans and stuff) You actually don't get to really see the internals other than IOPS which d…

The biggest "scam" if you can call it that is reducing all factors of CPU performance to "cores".

AWS is pretty transparent about what sort of cores you are exactly getting, and has different types available for different use-cases; typical example would something like r7iz that is aimed for peak single-threaded perf https://aws.amazon.com/ec2/instance-types/r7iz/

Re: SSDs have become fast, except in the cloud

#277

Post by tptacek »

kiwijamo wrote: post #275
tptacek wrote: post #235

Earlier quoted context omitted.

Yes! That is confusing! Tell them to stop it!

FYI it's not a AWS term, it's a DigitalOcean term.

I could not be more confused. Does EC2 quietly call their hosting machines "droplets"? I knew "droplets" to be a DigitalOcean team, but DigitalOcean doesn't have Nitro cards.

Re: SSDs have become fast, except in the cloud

#278

Post by ReflectedImage »

solardev wrote: post #223
hathawsh wrote: post #201

Earlier quoted context omitted.

That seems like a big opportunity for other cloud providers. They could provide SSDs that are actually physically attached and boast (rightfully) that their SSDs are a lot faster, drawing away business from older cloud providers.

For what kind of workloads would a slower SSD be a significant bottleneck?

Pretty much all work loads, work loads that are not affected would be the exception

Re: SSDs have become fast, except in the cloud

#279

Post by waynesonfire »

pclmulqdq wrote: post #11

This was a huge technical problem I worked on at Google, and is sort of fundamental to a cloud. I believe this is actually a big deal that drives peoples' technology directions. SSDs in the cloud are attached over a network, and fundamentally have to be. The problem is that this network is so large and slow that it can't give you anywhere near the performance of a local SSD. This wasn't a problem for hard drives, whi…

In other words, they're saving money. This is a fundamental problem with cloud providers. Value created from technological innovation is captured by the cloud provider and bare minimum is shared to reduce prices. The margins are ridiculous.

Re: SSDs have become fast, except in the cloud

#280

Post by bravetraveler »

magicalhippo wrote: post #270
bravetraveler wrote: post #245

Earlier quoted context omitted.

The storage driver may have more impact on VBox. You can get very impressive results with 'virtio' on KVM

Yeah I've yet to try that. I know I get a similar lack of performance with Bhyve (FreeBSD) using VirtIO, so it's not a given it's fast. I have no idea how AWS run their VMs, was just saying a slow storage driver could give such results.

> just saying a slow storage driver could give such results

Oh, absolutely - not to contest that! There's a whole lot of academia on 'para-virtualized' and so on in this light.

That's interesting to hear about FreeBSD; basically all of my experience has been with Linux/Windows.

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