It seems that every cloud service of note has a free tier nowadays and the Oracle Cloud is the latest that I’ve discovered (thanks to r/homelab which I highly recommend reading). Here’s Oracle’s summary of what they offer for free [1].
Oracle’s “always free” tier (where presumable “always” is defined as “until we change our contract”) currently offers ARM64 VMs to a total capacity of 4 CPU cores, 24G of RAM, and 200G of storage with a default VM size of 1/4 that (1 CPU core and 6G of RAM). It also includes 2 AMD64 VMs that each have 1G of RAM, but a 64bit VM with 1G of RAM isn’t that useful nowadays.
Table of Contents
Web Interface
The first thing to note is that the management interface is a massive pain to use. When a login times out for security reasons it redirects to a web page that gives a 404 error, maybe the redirection works OK if you are using it when it times out, but if you go off and spend an hour doing something else you will return to a 404 page. A web interface should never refer you to a page with a 404.
There doesn’t seem to be a way of bookmarking the commonly used links (as AWS does) and the set of links on the left depend on the section you are in with no obvious way of going between sections. Sometimes I got stuck in a set of pages about authentication controls (the “identity cloud”) and there seems to be no link I could click on to get me back to cloud computing, I had to go to a bookmarked link for the main cloud login page. A web interface should never force the user to type in the main URL or go to a bookmark, you should be able to navigate from every page to every other page in a logical manner. An advanced user might have their own bookmarks in their browser to suit their workflow. But a beginner should be able to go to anywhere without breaking the session.
Some parts of the interface appear to be copied from AWS, but unfortunately not the good parts. The way AWS manages IP access control is not easy to manage and it’s not clear why packets are dropped, Oracle copies all this. On the upside Oracle has some good Datadog style analytics so for a new deployment you can debug IP access control by seeing records of rejected packets. Just to make it extra annoying when you create a rule with multiple ports specified the web interface will expand it out to multiple rules for one port each, having ports 80 and 443 on separate lines doesn’t make things easier. Also it forces you to have IPv4 and IPv6 as separate rules, so if you want HTTP and HTTPS on both IPv4 and IPv6 (a common requirement) then you need 4 separate rules.
One final annoying thing is that the web interface doesn’t make your previous settings a default. As I’ve created many ARM images and haven’t created a single AMD image it should know that the probability that I want to create an AMD image is very low and stop defaulting to that.
Recovery
When trying a new system you will inevitably break things and have to recover things. The way to recover from a configuration error that prevents your VM from booting and getting to a state of allowing a login is to go to stop the VM, then go to the “Boot volume” section under “Resources” and use the settings button to detach the boot volume. Then you go to another VM (which must be running), go to the “Attached block volumes” menu and attach it as Paravirtualised (not iSCSI and not default which will probably be iSCSI). After some time the block device will appear and you can mount it and do stuff to it. Then after umounting it you detach it from the recovery VM and attach it again to the original VM (where it will still have an entry in the “Boot volume” section) and boot the original VM.
As an aside it’s really annoying that you can’t attach a volume to a VM that isn’t running.
My first attempt at image recovery started with making a snapshot of the Boot volume, this didn’t work well because the image uses EFI and therefore GPT and because the snapshot was larger than the original block device (which incidentally was the default size). I admit that I might have made a mistake making the snapshot, but if so it shouldn’t be so easy to do. With GPT if you have a larger block device then partitioning tools complain about the backup partition table not being found, and they complain even more if you try to go back to the smaller size later on. Generally GPT partition tables are a bad idea for VMs, when I run the host I don’t use partition tables, I have a separate block device for each filesystem or swap space.
Snapshots aren’t needed for recovery, they don’t seem to work very well, and if it’s possible to attach a snapshot to a VM in place of it’s original “Boot volume” I haven’t figured out how to do it.
Console Connection
If you boot Oracle Linux a derivative of RHEL that has SE Linux enabled in enforcing mode (yay) then you can go to the “Console connection”. The console is a Javascript console which allows you to login on a virtual serial console on device /dev/ttyAMA0. It tells you to type “help” but that isn’t accepted, you have a straight Linux console login prompt.
If you boot Ubuntu then you don’t get a working serial console, it tells you to type “help” for help but doesn’t respond to that.
It seems that the Oracle Linux kernel 5.4.17-2102.204.4.4.el7uek.aarch64 is compiled with support for /dev/ttyAMA0 (the default ARM serial device) while the kernel 5.11.0-1016-oracle compiled by Oracle for their Ubuntu VMs doesn’t have it.
Performance
I haven’t done any detailed tests of VM performance. As a quick test I used zstd to compress a 154MB file, on my home workstation (E5-2620 v4 @ 2.10GHz) it took 11.3 seconds of CPU time to compress with zstd -9 and 7.2s to decompress. On the Oracle cloud it took 7.2s and 5.4s. So it seems that for some single core operations the ARM CPU used by the Oracle cloud is about 30% to 50% faster than a E5-2620 v4 (a slightly out of date server processor that uses DDR4 RAM).
If you ran all the free resources in a single VM that would make a respectable build server. If you want to contribute to free software development and only have a laptop with 4G of RAM then an ARM build/test server with 24G of RAM and 4 cores would be very useful.
Ubuntu Configuration
The advantage of using EFI is that you can manage the kernel from within the VM. The default Oracle kernel for Ubuntu has a lot of modules included and is compiled with a lot of security options including SE Linux.
Competitors
AWS offers 750 hours (just over 31 days) per month of free usage of a t2.micro or t3.micro EC2 instance (which means 1GB of RAM). But that only lasts for 12 months and it’s still only 1GB of RAM. AWS has some other things that could be useful like 1 million free Lambda requests per month. If you want to run your personal web site on Lambda you shouldn’t hit that limit. They also apparently have some good offers for students.
The Google Cloud Project (GCP) offers $300 of credit.
https://cloud.google.com/free/docs/gcp-free-tier#free-tier-usage-limits
GCP also has ongoing free tier usage for some services. Some of them are pretty much unlimited use (50GB of storage for “Cloud Source Repositories” is a heap of source code). But for VMs you get the equivalent of 1*e2-micro instance running 24*7. A e2-micro has 1G of RAM. You also only get 30G of storage and 1GB of outbound data. It’s clearly not as generous an offer as Oracle, but Oracle is the underdog so they have to try harder.
https://azure.microsoft.com/en-us/free/
Azure appears to be much the same as AWS, free Linux VM for a year and then other less popular services free forever (or until they change the contract).
https://www.ibm.com/cloud/free
The IBM cloud free tier is the least generous offer, a VM is only free for 30 days. But what they offer for 30 days is pretty decent. If you want to try the IBM cloud and see if it can do what your company needs then this will do well. If you want to have free hosting for your hobby stuff then it’s no good.
Oracle seems like the most generous offer if you want to do stuff, but also one of the least valuable if you want to learn things that will help you at a job interview. For job interviews AWS seems the most useful and then GCP and Azure vying for second place.
One important aspect of the free offerings is traffic allowance. I’ve tried to summarize the offerings in a table https://gitlab.com/ptman/matrix-docs/-/tree/master/free-matrix-server#get-a-free-server . There’s also the list at https://free-for.dev/
Paul: Thanks for those quality links!
Also Oracle has a limit to the number of free tier VMs available in a region. If that limit is hit (like 2 days ago for Melbourne Australia) then no more can be created. I had 2 VMs running each with 1 CPU core, I wanted a VM with 2 cores and it wouldn’t let me create it. I killed the second VM (thinking it was a limit for me) and tried creating another but that failed, I couldn’t even create a VM with 1 core after that.
Now I’m being careful with my running VM, if I stop it I might not be able to start it again until Oracle buys more hardware!