tailieunhanh - Smart Home Automation with Linux- P12

Smart Home Automation with Linux- P12:I will end on a note of carefree abandon—learn to steal! Once you’ve learned the pieces of the puzzle and how to combine them, there is very little new to invent. Every new idea you discover is a mere permutation of the old ideas. And ideas are free! Every cool feature discussed on TV shows or presented in the brochures or web sites of commercial HA companies can be taken, adapted, and implemented with the information presented here using very little effort | CHAPTER 3 MEDIA SYSTEMS Note Using hardware RAID solutions is a double-edged sword for some system administrators. They work seamlessly and take no effort to set up and maintain. However if the RAID system has a problem and uses a custom disk format then it might be impossible to recover the data on the disk. You can solve this by buying two pieces of hardware and verifying that you can swap the disks without a problem before they are put into active service. Alternatively you can check with the manufacturer that the disk format used either is known or comes with suitable software recovery tools. Backing up data such as DVD or music rips doesn t and shouldn t require RAID although having one does no harm. Since this type of data changes less frequently you can make do with an external USB hard drive plugged into your desktop machine. You can then run the backup software of your choice see Chapter 6 for some possibilities here to copy only those files that have changed and then unplug and store the drive. This prolongs the life of the drive and is worthy of the extra effort. As with all backups they are useless unless tested regularly so make sure that you do test them. Some people will test them by copying their backups to a new drive every 6 to 12 months. The cost is negligible compared to the many hours spent ripping and organizing the data. Furthermore the price per gigabyte comes down every year allowing you store more data in a smaller form factor. If you are desperate for extra space you can then reuse the older drive elsewhere in your system. Although tape backup systems are a favorite of most businesses the cost and convenience of USB hard drives render them unnecessary for the home market. Note Hard drives either fail in the first few weeks or the day before you remember to back up. Therefore when buying disks always buy from different manufacturers and at different times so if you get one disk from a bad batch IBM Death Star hang your head you minimize .