Understanding Linode

You can only run one instance at a time on a linode.

@glg:

You can only run one instance at a time on a linode.

By that, you mean I can only run one disk image at a time?

One configuration profile at a time.

For multiple concurrently running instances you'll want multiple Linodes.

Hope that helps!

-Chris

@caker:

One configuration profile at a time.

For multiple concurrently running instances you'll want multiple Linodes.

Hope that helps!

-Chris

Thanks! That made sense!

OK, so Chris said you can run only one configuration profile at a time … but a configuration profile can have multiple disk images. So, just to be sure, is Chris saying you can only run one disk image at a time?

You can have multiple disk images mounted at once but only one operating system running.

Think of a Linode instance as a computer, and disk images as real physical disks. You can have many disks attached to it (via configuration profile), or many operating systems installed, but on one computer only one OS will run at the same time.

> Think of a Linode instance as a computer, and disk images as real physical disks. You can have many disks attached to it (via configuration profile), or many operating systems installed, but on one computer only one OS will run at the same time.

So I can have One Linode with two disks running at the same time? How do I ssh to the different disk images?

And what are the advantages of doing this instead of one image with several VPS'es for different sites?

@thorandre:

> Think of a Linode instance as a computer, and disk images as real physical disks. You can have many disks attached to it (via configuration profile), or many operating systems installed, but on one computer only one OS will run at the same time.

So I can have One Linode with two disks running at the same time? How do I ssh to the different disk images?

And what are the advantages of doing this instead of one image with several VPS'es for different sites?

2 disks != 2 OS's running at the same time.

@thorandre:

So I can have One Linode with two disks running at the same time? How do I ssh to the different disk images?

Yes, "running", but you can only boot from one, or the other, just like in a physical computer, not from both at the same time.

So what is the benefit of using for example two ext3 disks?

@thorandre:

So what is the benefit of using for example two ext3 disks?

There isn't one! (For what you're thinking of)

@thorandre:

So what is the benefit of using for example two ext3 disks?

Each Linode disk image contains single partition, so if you wanted different partitions, you'd need more than one disk image, unless you want to roll your own partitioning solution on single disk image, which is not something I would advise because you lose backup ability for that image and you essentially run an abstraction atop abstraction atop abstraction.

Having said that, whether or not having multiple partitions is a benefit is open to discussion. Personally I like to separate stuff that requires journaling from temporary data, ro (root) vs rw (var and similar), etc…

@thorandre:

So what is the benefit of using for example two ext3 disks?
If you're only going to have a single system, there isn't one. (Such as production environment websites.)

But if you're trying out two different Linux distros, but are going to use the exact same data (directory structure and files for websites, etc), both these distro installations can use the same partition for data (ie. one profile boots with distro X and mounts the data partition, and another profile boots with distro Y, also mounting the same data partition).

I don't do it with linode but I like to have multiple partitions on physical computers I admin:

/ - duh

/boot - kernel, grub

/home - home directories

/srv - databases, torrents (only the FOSS kind, I swear!), web content, etc

/usr/local - I don't use it much, some custom shell scripts

/opt/texlive - where I install the TeX Live system

The advantage to having them be different partitions for me primarily is OS upgrade. I can format / for a clean install but leave the others alone.

Since I use LVM (except for /boot - it's ext2 primary, don't even see point of journaling for that) I can adjust partition sizes as needed.

With Linode, I think the easiest way to upgrade is to buy another linode, set it up, migrate data (rsync over ssh, use IPv6 and within same data center it is free), test it, change DNS (or bring up old IPs on new box), delete old Linode.

So I don't see a personally need to use different disk images in Linode.

Backing up data using Linode's backup service could be considered a valid reason to some. I'm sure there are other valid reasons some have as well.

The first time you'll have a runaway process spamming into /var/log and filling your disk to 100% you'll learn to put that directory on a separate disk/partition…

… or not, I stil don't do it after experiencing such incident. ;)