Know How... 78

Got a few old computers lying around? Want an enterprise-level storage box? Expert guest Patrick Norton shows us how to create a FreeNAS using old system parts.

Feedback!

Thanks for our listeners who participate in the KH Community!

Featured Users

• Mike Marien wanted to know if we should use the same SSID on multiple APs.
• Warren Blesofsky was wondering if "Windows Defender" is the only malware defense he should run on his Windows PC.
• Vivek Dhutia has a great "Solar Pi" server that he NEEDS to send a picture of.
• Neil Tsubota asked about the practical reasons for using static IP addresses.
• Lee Roche is thinking about making an advanced test bench.

** If you plan to reuse an old ATX Power Supply, connect pins 14 & 15.

RAID

Here's a bunch of RAID stuff from Wikipedia.

RAID 0 comprises striping (but no parity or mirroring). This level provides no data redundancy nor fault tolerance, but improves performance through parallelism of read and write operations across multiple drives. RAID 0 has no error detection mechanism, so the failure of one disk causes the loss of all data on the array.

RAID 1 comprises mirroring (without parity or striping). Data are written identically to two (or more) drives, thereby producing a "mirrored set". The read request is serviced by any of the drives containing the requested data. This can improve performance if data is read from the disk with the least seek latency and rotational latency. Conversely, write performance can be degraded because all drives must be updated; thus the write performance is determined by the slowest drive. The array continues to operate as long as at least one drive is functioning.

RAID 2 comprises bit-level striping with dedicated Hamming-code parity. All disk spindle rotation is synchronized and data is striped such that each sequential bit is on a different drive. Hamming-code parity is calculated across corresponding bits and stored on at least one parity drive. This level is of historical significance only. Although it was used on some early machines (e.g. the Thinking Machines CM-2), it is not used by any current commercially available systems.

RAID 3 comprises byte-level striping with dedicated parity. All disk spindle rotation is synchronized and data is striped such that each sequential byte is on a different drive. Parity is calculated across corresponding bytes and stored on a dedicated parity drive. Although implementations exist, RAID 3 is not commonly used in practice.

RAID 4 comprises block-level striping with dedicated parity.

RAID 5 comprises block-level striping with distributed parity. Unlike in RAID 4, parity information is distributed among the drives. It requires that all drives but one be present to operate. Upon failure of a single drive, subsequent reads can be calculated from the distributed parity such that no data is lost. RAID 5 requires at least three disks.

RAID 6 comprises block-level striping with double distributed parity. Double parity provides fault tolerance up to two failed drives. This makes larger RAID groups more practical, especially for high-availability systems, as large-capacity drives take longer to restore. As with RAID 5, a single drive failure results in reduced performance of the entire array until the failed drive has been replaced.

FreeNAS

Network Attached Storage products have become more commonplace as users demand access to their data on all their network-connected devices. FreeNAS is a FreeBSD-based operating system that installs in 2GB of space and can turn your old hardware into an enterprise-level storage box.

What you'll need

• Computer: You want the fastest processor you can salvage, a motherboard that supports AT LEAST 4GB of memory and has multiple SATA ports, a case with many drive bays, and a 300W and Power Supply.
• DRIVES!: You can use any drives you've got running around while you're learning FreeNAS, but when you decide to build a FreeNAS box that will serve as your permanent storage you should consider using either the WD GREEN or WD RED series of drives. They run cooler, quieter and use less power.
• PCI SATA card (Optional)
• Flash Drive: 4GB
• Monitor + Keyboard
• Blank CD
• USB CD-ROM drive
• A second network-connected computer that can be used to configure the FreeNAS box

What you'll do

1. Download the latest FreeNAS disto and burn it to CD-ROM
2. Open the computer and strip out the hard drives and optical drives. You want to save all the drive bays and SATA ports for the array drives.
3. Plug the Flash drive into a USB port
4. Connect all your drives to the motherboard. You MAY need additional SATA power breakout cables. You may also need a PCI SATA board if you want to install more drives in the case than the motherboard supports.
5. Connect the monitor and keyboard to the computer, the connect the computer to your network.
6. Power up the PC: Load the CD into your USB optical drive and make sure it's set to boot from that optical drive
7. Install FreeNAS on the USB Key
8. Log into the FreeNAS box. (The IP address will show up on the screen connected to the FreeNAS box.)

Connect with us!

Don't forget to check out our large library of projects on this site. If you want to search for a topic, try this custom search engine.

• Tweet at us using the hashtag #twitkh
• Email us at knowhow@twit.tv