Minimum Recommended Ram for Docker usage


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Hey Folks,

 

I'm just setting up a new server for a friend, and am wondering what I can comfortably get away with as far as Docker and Ram are concerned.

 

This server is going to serve documents and video (No transcoding. Just a repository that XBMC grabs from), and run 2 dockers (Sabnzbd and Sickbeard).

 

i3-4150 cpu and 2GB of ram. Would that be sufficient to comfortably run?

 

I have exactly 0 experience using Docker, so any real life experience with only 2GB of ram and Docker, or, barring that, recommended best practices, would be appreciated! :).

 

I checked out JonP's post, and it looks like around 1250MBs on fresh start, but that table doesn't include usage...

 

My biggest concern would be when par checks or unrar is occurring, will it impact other actions (Like streaming video). I could buy more ram, but I'm trying to keep the cost down, and even 1 4GB stick of ecc ram for this server looks to run around $90 with shipping and tax...

 

Thanks for any advice!

 

DB

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There is no real minimum ram required for docker usage.

 

It all depends on which applications you're running. This is no different if you use plug-ins instead of dockers. So the question is how do those applications you plan on using perform, can they be configured to use minimal resources, can you replace them with apps that require less resources.  I think it's been said that nzbget uses less resources than sabnzbd.

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Hey Folks,

 

I'm just setting up a new server for a friend, and am wondering what I can comfortably get away with as far as Docker and Ram are concerned.

 

This server is going to serve documents and video (No transcoding. Just a repository that XBMC grabs from), and run 2 dockers (Sabnzbd and Sickbeard).

 

i3-4150 cpu and 2GB of ram. Would that be sufficient to comfortably run?

 

I have exactly 0 experience using Docker, so any real life experience with only 2GB of ram and Docker, or, barring that, recommended best practices, would be appreciated! :).

 

I checked out JonP's post, and it looks like around 1250MBs on fresh start, but that table doesn't include usage...

 

My biggest concern would be when par checks or unrar is occurring, will it impact other actions (Like streaming video). I could buy more ram, but I'm trying to keep the cost down, and even 1 4GB stick of ecc ram for this server looks to run around $90 with shipping and tax...

 

Thanks for any advice!

 

DB

 

2GB RAM is going to be cutting it close, but you might be ok.  I would be more comfortable with 4GB on that system, but you're really close to the threshold.  As BRiT indicated, it really comes down to the apps and your usage.

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There is no real minimum ram required for docker usage.

 

It all depends on which applications you're running. This is no different if you use plug-ins instead of dockers. So the question is how do those applications you plan on using perform, can they be configured to use minimal resources, can you replace them with apps that require less resources.  I think it's been said that nzbget uses less resources than sabnzbd.

 

2GB RAM is going to be cutting it close, but you might be ok.  I would be more comfortable with 4GB on that system, but you're really close to the threshold.  As BRiT indicated, it really comes down to the apps and your usage.

 

Thanks for the input guys. I think it might be less hassle to just add some extra ram now, rather than trying to do it remotely a year from now if he starts adding a bunch of applications...

 

 

 

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IMHO its a false economy skimping on RAM. Not that long ago many Linux distros were all about how little RAM could be used and unRAID was no different. 512MB at one point worked fine.

 

However since the 64bit kernel came in the more RAM you have the better unRAID "feels" especially if you use cache_dirs. Why? because Linux is very god at using RAM if it has it so disks stay spun down more unless you need them. Resuming videos feel slicker cause last nights cache is still in RAM. NZBGET works better cause it has more ram to unpack and manipulate Usenet posts.

 

I could go on but simply put you will feel a difference between 2GB and 16GB... way more than if you chose a worse CPU and massively more than if you chose a cheap ass MB.

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IMHO its a false economy skimping on RAM. Not that long ago many Linux distros were all about how little RAM could be used and unRAID was no different. 512MB at one point worked fine.

 

However since the 64bit kernel came in the more RAM you have the better unRAID "feels" especially if you use cache_dirs. Why? because Linux is very god at using RAM if it has it so disks stay spun down more unless you need them. Resuming videos feel slicker cause last nights cache is still in RAM. NZBGET works better cause it has more ram to unpack and manipulate Usenet posts.

 

I could go on but simply put you will feel a difference between 2GB and 16GB... way more than if you chose a worse CPU and massively more than if you chose a cheap ass MB.

 

Some good points.

 

As much as I'd like to go with 16GB, I think I'll go with 6GB. Trying to get it up to 16GB will cost me more than the price of the server. This will be replacing an old Synology unit with 128MB of ram, so I'm pretty sure he'll be happy with the upgrade! :)

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I know it doesn't exactly answer your question, but I thought I would echo the sentiments NAS expressed earlier on RAM economy.

 

My initial rig had a stack of apps and 4GB of RAM, but would grind / stutter a bit under heavy load (it's now running 8GB without a hitch).

 

As a contrast, the new rig I'm toying with runs a Core i5, 16GB RAM and the following docker apps :

 

  • Plex (w/ Transcoding in Ram)
  • Headless XBMC
  • Sabnzbd
  • SickRage
  • CouchPotato
  • Headphones
  • TVHeadEnd
  • Maraschino
  • Transmission
  • WebGrab++
  • DUC

 

I'm serving up HD streams to 3-4 devices simultaneously, *while* running PAR2 checks, unZIP/unRAR operations and downloading new media streams @ 2-3Mbps in the background.

 

All of this runs as smooth as butter, using only 3-10% CPU on average.

 

Grab every bit of RAM you can afford early on.... it makes a considerable difference when running a number of apps. 

 

You'll always end up adding more apps than you originally intended  ;D

 

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So I've been experimenting with the existing 2GBs, and I'm not seeing any performance issues with Sickbeard and Sabnzbd dockers running... Though ram usage is @ 93% in the new Dynamix tab in unRaid...

 

Is that an accurate representation of ram being used, or does it reflect the OS using up any free ram for disk caching?

 

[EDIT] For the record, this was not a true representation of normal usage, as they were mostly empty instances, and no unraring or streaming going on at the same time... [/EDIT]

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A quick google shows this is one way to do it (still cmd line though.... Is there a better/visual way?):

 

To see how much ram is free to use for your applications, run free -m and look at the row that says "-/+ buffers/cache" in the column that says "free". That is your answer in megabytes

 

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Install the Dynamix System Stat plugin and then you'll get a new tab where you can see the CPU and memory usage curves.

 

http://lime-technology.com/forum/index.php?topic=36543.0

 

 

FYI, I have 6 dockers running and am only using 1.3gig of ram.

 

I thought that came built in now with v6.12? Or would the stand-alone plugin offer different info?

 

There are additional plugins you can add to Dynamix to add other features.

See here:

http://lime-technology.com/forum/index.php?topic=36543.0

 

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