Building the IDrive platform: How we use RAID

RAID stands for Redundant Array of Independent Disks – it is a standard method used to cluster many hard drives together into one unit for the purposes of space, speed and security. At IDrive, we use RAID to configure large amounts of fast storage that is many–many times more reliable than the hard drive in an off-the-shelf computer.

IDrive Online Backup uses a method of incremental transfers to backup and restore files. Our software automatically breaks up files into half-megabyte sections known as blocks and moves those around instead – it’s much more effective and reliable than attempting to transfer large whole files. RAID arrays use a similar function to break up files into small, manageable pieces.

Let’s discuss how RAID stores and protects blocks of data.

Since RAID arrays are made up of more than one disk it is possible to spread blocks out, this technique in knows as striping. Striping leads to a key advantage: blocks can be read from multiple disks at the same time, significantly reducing access times. IDrive Online Backup customers consistently rave about the speed of our network – RAID is one of the ways we are able to provide this kind of performance. Striping blocks across multiple disks introduces a disadvantage however: should one disk in the array fail, the data from the entire RAID is at risk of being lost. We overcome this with an important RAID feature known as parity.

At IDrive we used advanced storage techniques to safeguard our customers' data.
This diagram illustrates four physical disks that would appear to a computer as one large disk. Data is striped (blue) across the array and parity information (green) is distributed across the drives to safeguard files in the event of a failure.

A RAID configured to parity data creates one or more copies of special blocks that are used to reconstruct files that might otherwise be lost if one or more of the disks in the array fail; somewhat like a backup. IDrive RAID setups are very secure! Multiple disks would have to fail at the same time in order to result in files being lost – a highly-rare event. Our advanced storage arrays help us provide impressive performance and enterprise-level reliability to our nearly 700K customers.

For IDrive Pro and IDrive Basic customers we hold data on one of these sophisticated arrays in one of our SAS 70 certified data-centers. We periodically backup IDrive Pro customers’ data onto a second RAID array as an extra layer of protection in the unlikely event of a failure. The IDrive Pro solution is perfect for businesses interested in regulation compliance.

IDrive Unlimited customers’ data is also held on one of our RAID servers however we don’t perform a secondary backup to a secondary array.

Send your online backup, cloud storage and other data questions to!

Have a great Wednesday – S. Gold, Business Dev. Manager

UPDATE on 3/24/2011

Brad C. e-mailed regarding the past experiences a few other online backup companies have had trusting RAID: RAID is one of the most powerful and safe methods of storing large amounts of data, however, it is certainly not bulletproof. IDrive’s performance and security measures go far beyond the hard disks that safeguard our clients’ files. The heart of IDrive is our software which was built by us to constantly error-check and verify data – it’s very good at it too. Our storage facilities have always maintained a very high level of reliability.