Since Cloud Block Storage is a relatively new product offering at Rackspace, I thought it might be helpful to give you three best practices as you start using it with your cloud configuration.
First, it is important to understand the differences between throughput and random I/O. Throughput is very important for the general use cases of writing sequential data to your drives, such as having extra space for logging, streaming data or basic file access. It is important to note that throughput will be roughly the same for both our Standard volumes (SATA) and Solid State Drive (SSD) offerings. If you are just looking for a way to store extra data, you will be best served with the Standard Cloud Block Storage volume.
Random I/O is very important for application, database and NoSQL servers – essentially, it is important for any server that needs to be able to quickly write to random parts on the disk. In this case, our SSD offering is many times faster than our Standard offering, and will be the best solution when you are looking to improve performance of random I/O.
Another best practice considers when to place your Cloud Block Storage drives in a RAID configuration. If you are in a High Availability (HA) environment and you want to make sure that your data is available, you would generally follow the same best practices for setting up a RAID array as you would with a dedicated environment. You can set up your Cloud Block Storage volumes in a RAID array, usually a mirrored configuration, to help provide extra redundancy and durability. This means that if a drive goes away or fails, you can easily replicate your data and replace another drive in the RAID array.
However, we do not recommend using RAID to enhance the performance of your Cloud Block Storage volumes. Setting up the Stanard drives in a RAID array will not give you as good of an experience as using the SSD Cloud Block Storage volumes. So remember: when you need extra performance, be sure to use SSDs.
Finally, whether you are using RAID or not, it is always a good idea to back up your data, and there are two different ways you can do this. Using the control panel or API, you can back up your Cloud Block Storage volumes to Cloud Files. This will give you a durable backup and you can use that to create new volumes down the road. The other option is to use Cloud Backup to make a file level backup of your block device. This will give you the capability to restore a specific file (such as a document) at any point in time; you won’t have to restore your entire drive just to restore that one file.
These are some of the best practices I’ve seen while using Cloud Block Storage. If you come across any others, be sure to comment on this post and let us know!
Previously, Chuck discussed some of the differences between Cloud Files and Cloud Block Storage. Be sure to check out this page to find out how to get started with Cloud Block Storage on the Rackspace Cloud powered by OpenStack.