Why did Meteor v0.4.x (MongoDB?) use to take up ~3GiB of disk space for a very simple app? [duplicate]

Question

UPDATE: this was fixed after Meteor v0.4 (2012). For historical purposes:

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I'm testing Meteor on a micro EC2 Ubuntu 11.10 instance (8GiB) and upon installing it and logging in I ran the df command to see how much memory had been consumed by core files (about 10%):

Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/xvda1             8256952    782068   7055456  10% /
udev                    295276         4    295272   1% /dev
tmpfs                   121248       148    121100   1% /run
none                      5120         0      5120   0% /run/lock
none                    303112         0    303112   0% /run/shm

Upon installing NodeJS & NPM I again ran df to determine how much more room had been consumed and it didn't look like much (an additional 2%):

Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/xvda1             8256952    919444   6918080  12% /
udev                    295276         4    295272   1% /dev
tmpfs                   121248       148    121100   1% /run
none                      5120         0      5120   0% /run/lock
none                    303112         0    303112   0% /run/shm

I then went about installing MongoDB, and as expected, this took quite a lot more memory (59% of disk space in use):

Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/xvda1             8256952   4585884   3251640  59% /
udev                    295276         4    295272   1% /dev
tmpfs                   121248       148    121100   1% /run
none                      5120         0      5120   0% /run/lock
none                    303112         0    303112   0% /run/shm

However, upon installing Meteor, curl install.meteor.com | /bin/sh creating the sample myapp from their site meteor create myapp and running myapp cd myapp & meteor I successfully saw the app in the browser displaying "Hello World" (etc), on the terminal side I saw this:

[[[[[ ~/myapp ]]]]]

Initializing mongo database... this may take a moment.
Running on: http://localhost:3000/
^C

Upon closing the server I checked df one last time and was surprised to see a disk full!?

Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/xvda1             8256952   7778748     58776 100% /
udev                    295276         4    295272   1% /dev
tmpfs                   121248       148    121100   1% /run
none                      5120         0      5120   0% /run/lock
none                    303112         0    303112   0% /run/shm

My question is: why did Meteor (MongoDB?) take up ~3GiB disk space for a very simple app?

Is there a way of reducing this consumption of disk space?

Thanks!

Answer 1

This is fixed on the development branch of meteor and will be in the next release.

https://github.com/meteor/meteor/commit/6042b91a9ca75fc47b2477e613da093f1c9b943e

It seems mongo defaults to using huge files and has to be told not to. Understandable for the normal use case of mongo, I guess. By preallocating big files they can improve performance in some cases.