USB RAID Array on Ubuntu 14.04 LTS - Part Three
For some time now, I have felt the need for a relatively cheap RAID array for my Ubuntu Linux Machine that would be reliable and fast but not break the bank. Almost all the RAID solutions I came across were quite expensive and so I decided to build my own.
Part One - Covered the alternatives and the selection of USB Thumb Drives with a USB hub as a RAID Level 5 Array and also how to install the software utilities we would need later.
Part Two - Goes over basics of RAID arrays and the rationale behind selecting RAID 5.
Part Three - In this part we will go over the procedure to take some "before" performance benchmarks against which we can compare the performance of the RAID array.
Part Four - Procedure to creating your software controlled RAID array using the utilities we installed in Part One.
Part Five - Goes over the performance benchmarks of the RAID Level 5 array we created and also take a look at some applications of such arrays.
Benchmarking Procedures
- IMPORTANT - Ensure that you don’t have any precious data on your thumb drives as all data will be lost once you begin the process of Benchmarking.
- On Ubuntu find the Disks utility using Ubuntu Search on the toolbar and click on the application to open it.
Disks Utility showing Thumb Drive
- Insert One of the Thumb drives into the USB port of the computer [Directly connect the Thumb Drive to the computer without using a Hub]
- Select the Thumb Drive in the Disks utility and replace the W95 FAT32 partition that is typically on Thumb Drives by Linux Ext4. You can do by clicking on the meshed gearwheels icon with the tooltip “More actions” that is located below the Volumes information on the right side of the application and selecting Format in the dropdown list and then selecting Ext4 in the Type drop down.
- Once the Thumb Drive is ready, again click on “More actions” and select Benchmark. Leave the defaults and click on Start Benchmark.
Benchmark for Thumb Drive connected directly to Computer
- Now safely eject the Thumb drive by dismounting and then ejecting it. Reconnect it to the USB port of the computer via the hub that you will be using to create the RAID Array.
- Once the Thumb Drive is recognized, again click on “More actions” and select Benchmark. Leave the defaults and click on Start Benchmark.
Benchmark for Thumb Drive connected via Hub to Computer
Summary
Looking at the two benchmark charts, we can see that the Read performance via the Hub has dropped but the Write performance is identical. This could be because I used a low-cost hub to keep the array compact. However we will look into this in greater detail in Part Five when we have the "after" benchmarks for the RAID array as well.
Finally, it is time to create our software RAID array.