
Running DC/OS on Small Digital Ocean Droplets - djsumdog
http://penguindreams.org/blog/installing-mesosphere-dcos-on-small-digital-ocean-droplets/
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josep2
Great write up!

I've had similar experience with startup and installation while running on
Packet with much more beefy machines. Overall, DCOS is really nice to have but
it is not without it's headaches so far.

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justinholmes
I switched off as soon as I saw 'swapon'

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Alupis
> I switched off as soon as I saw 'swapon'

Why? We're discussing running systems with as little at 512MB of RAM, but have
60GB of HDD.

Swap may not be as fast as RAM, but it's sure a heck of a lot better than
crashing when your system needs 513MB for an instant...

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sgloutnikov
"Although swap is generally recommended for systems utilizing traditional
spinning hard drives, using swap with SSDs can cause issues with hardware
degradation over time. Due to this consideration, we do not recommend enabling
swap on DigitalOcean or any other provider that utilizes SSD storage. Doing so
can impact the reliability of the underlying hardware for you and your
neighbors. This guide is provided as reference for users who may have spinning
disk systems elsewhere.

If you need to improve the performance of your server on DigitalOcean, we
recommend upgrading your Droplet. This will lead to better results in general
and will decrease the likelihood of contributing to hardware issues that can
affect your service."

~~~
Alupis
1) Hardware degradation is not for you to worry about as a user. That's for
DigitalOcean (or any other cloud provider) to worry about. You specifically
pay them so you don't have to worry about hardware issues.

2) I have serious doubts that a rarely-used small 512MB swap file is going to
degrade hardware and lead to performance issues for either your VM or your
neighbors. Even if it did, see point #1 above.

> Doing so can impact the reliability of the underlying hardware for you and
> your neighbors

This sounds like they're concerned about thrashing disk I/O... to which I'd
say it sounds like they've under-spec'd/over-sold the host server if one VM
swapping can degrade performance for all guests. Do they not have upper-
bounded I/O quotas or I/O balancing? Can a single VM doing heavy disk I/O that
is not Swap cause the same performance degradation? It seems so...

> If you need to improve the performance of your server on DigitalOcean

No, having Swap is not about improving performance, it's about keeping your
system up and running in the rare event it exceeds the allocated RAM. Kernel
Panics are not fun, and it's generally better to run with reduced-performance
than not to run at all - at least until the Admin has time to make the
appropriate changes to either rein-in the runaway RAM usage, or upgrade to
more RAM.

> we recommend upgrading your Droplet

They would recommend that, wouldn't they...

