What is RAID?
RAID is a “Redundant Array of Independent Disks” and as its name suggests, it is an array of hard disks connected together so that data can be replicated automatically without the user having to do it manually.
Why redundancy?
Storage devices are not always very reliable. Hard disk failure is still one of the common causes of data loss. Redundancy increases reliability by replicating the data across multiple disks.
There are two types of reliability
- Reliability of the data being safe.
- Reliability of data being available when you need it. The availability of data is the amount of time when the data is “online”.
Data backed up on a DVD or an external hard disk satisfies the first type of reliability, that it is being kept safe, but not the second one as it is not “online”.
This is where RAID comes into picture. RAID being a redundant array of disks, data will always be stored on more than one disk (except for RAID 0).
If one disk fails, the RAID controller will automatically start pulling data from the other disk. So that means, even if one disk fails, the data is still “online”. When the faulty disk is replaced with the new one, the RAID controller will automatically start replicating the data to the new disk.
Did you say RAID 1?
There are different levels of RAID, like RAID 0 through 5. “RAID 1” is a setting where there are 2 hard disks in the RAID array. Data on one hard disk is replicated exactly on the other one. This is probably not the best of the RAID arrays, however, for a home setting I think this would more than suffice.
Do we need a RAID server in a home setting?
The quick answer would be no. But if you are like me who has a ton of photos accumulated over the past many years and plenty of home videos of family, friends and kids and really care about all those data not getting lost, a RAID will give that additional layer of protection to your data.
Can RAIDs fail too?
Of course it can! If you have a 2 disk RAID array and if both the disks goes bad (like a power surge), or if there is a hardware failure on your RAID controller, then all the data will be gone. Even if you have a RAID, you will still need a good backup strategy. A RAID cannot replace a good backup strategy, but can only complement it.
What is NAS?
NAS or a Network Attached Storage is a device that can connect to your network, in this case your home network. Multiple computers and devices in your home can access all the files stored in the NAS.
Can’t you connect your storage device directly to your computer?
Well, yes. However, it will be limited to just one computer. I wanted a solution where all the computers at home can access all the files on the storage device. Network Attached Storage is what makes this possible. Your storage device is directly connected to your home network through the router. All your computers are also connected to the home network through the router, which in turn can connect to the storage device.
Hardware Setup
After evaluating a lot of RAID systems, I finally decided on a Synology DS210j. This has 2 drive bays in it and allows wither RAID 0 or a RAID 1 setup.
It turned out that setting this up was the easiest part. The model that I bought does not come bundled with hard disks. So I bought 2 x 1TB hard disks separately and installed it. It supports a maximum of 4TB. The installation of the hard disks was a breeze. Remove couple of screws, slide the hard disks in the slot one at a time and then put the screws back on.
Then I connected this to my router through an ethernet cable, connected the power supply and switched it on.
In a RAID 1 setting, 2TB of storage space would give me effective storage of 1TB, as the rest will be used for redundancy.
Software Setup
Synology’s management user interface is just incredible. It is web based, very user friendly and ajax supported. Multi-tasking is also supported in the management web page.
See the control panel, shown in Figure A, to get a glimpse of what features are being supported on this device. It has its own embedded Web Server running on php and a MySql database. It also supports dynamic DNS notifications. It has a lot of other nicer features like a Media Server, iTunes Server, Audio Station, Photo Station, Download Station and a Surveillance Station.
Figure A
I connected to the Synolgy’s managemet software, which I installed on my computer. It allows me to manage the device including the hard disks, the RAID configuration and other network settings.
To start with, I formatted both the hard disks on RAID1 configuration. Configured the network to use DHCP. Created users and groups and assigned permissions to each of them.
Then I moved all the data from my computer / external hard drives / CDs / DVDs etc. The copying out is not all that fast as I’m connecting to this device from my computer over a wireless connection. However, when I connected my computer over ethernet, the file transfer was reasonably fast.
Please see a sample screenshot of the management user interface below in Figure B.
Figure B
I’m very glad that all my scattered data is now stored in a central location. All my computers including our xbox media center can access all the photos, videos and other data anytime and anywhere in the house.
I love it!
Footnotes:
You can find out more about RAID in this wiki:
http://en.wikipedia.org/wiki/RAID
You can find more about NAS in this wiki:
http://en.wikipedia.org/wiki/Network-attached_storage
Synology link:
http://www.synology.com/enu/products/DS210j/index.php