Linux, politics, and other interesting things
I’ve just been setting up new virtual servers at Linode  and Slicehost . I have previously written a review of both those services , based on that review (and some other discussions) one of my clients now has a policy of setting up pairs of virtual servers for various projects, one server at Linode and one at Slicehost.
Now both virtual hosting providers work very well and I’m generally happy with both of them.
But Linode seems to be a better offering.
Linode has graphs of various types of usage, I can look at graphs of disk IO, CPU use, and network IO for the last 24 hours, 30 days, or for previous months. The three graphs have the same scale of the X axis so I can correlate them. The stats on Slicehost just allow you to get the current raw numbers, which doesn’t help if I want to know what happened last night when performance sucked.
When I build a Linode instance I can have multiple filesystems configured (Slicehost can’t do any of this). I can use less disk space than is available to reserve space for other filesystems. Separating filesystems makes it easier to track IO performance and also allows some bounds to be set on the amount of disk space used for various tasks. Nowadays the use of multiple partitions is not as popular as it once was, but it’s still a real benefit. Of course one of the benefits of this is that I can have two partitions on Linode that are suitable for running as the root filesystem. If an upgrade fails then it would be an option to boot with the other filesystem (I haven’t actually done this but it’s good to have the option).
I believe that this feature of Linode could do with some improvements. Firstly when creating or resizing filesystem it should be possible to specify the number of Inodes when using Ext3. The fsck time for a large Ext3 filesystem that has the default number of Inodes is quite unreasonable. It would also be good if other filesystems such as XFS were supported, for some use cases XFS can significantly outperform Ext3 – and choice is always good. When BTRFS becomes stable I expect that every hosting provider will be compelled to support it (any provider that wants my continued business will do so).
Now Linode and Slicehost both allow sharing bandwidth allowances between virtual servers. So if you run one server that uses little bandwidth you can run a second server that needs a lot of bandwidth and reduce the potential for excess bandwidth use problems. The next logical extension to this is to allow sharing disk allocation between servers on the same physical system. So for example I might want to run a web server for the purpose of sending out large files, 360M of RAM as provided by the Linode 360 offering would be plenty. But the 128G of storage and 1600GB per month of bandwidth usage that is provided with the Linode 2880 plan would be really useful. At the same time a system that does computationally expensive tasks (such as a build and test server) might require a large amount of RAM such as 2880MB while requiring little disk space or bandwidth. Currently Linode allows sharing bandwidth arbitrarily between the various servers but not disk space or RAM. I don’t think that this would be a really difficult feature to implement.
Finally Linode has a “Pending Jobs Queue” that shows the last few requests to the management system and their status. It’s not really necessary, but it is handy to see what has been done and it gives the sysadmin a feeling of control over the process.
These management features provide enough value to me that if I was going to use a single virtual hosting provider then I would choose Linode. For certain reliability requirements it simply wouldn’t be a responsible decision to trust any single hosting company. In that case I’m happy to recommend both Linode and Slicehost as providers.