Raid, what and why do you care?
Siig Sata Raid : RAID stands for Redundant Array of hard intelligence. Sometimes the acronym is referred to as Redundant Array of smart devices or Redundant Array of Independent Disks. In any case, is a group of hard drives are ready to optimize their storage to meet your individual needs. The optimization is performed with the software (RAID) or hardware (Hardware RAID). Hard drives configured in a RAID configuration is called the matrix. There are many types of RAID arrays, some of which you can see that it relates is RAID 0, RAID 1, RAID 5, RAID 6, JBOD and then merge the arrays are sometimes referred to a series of two-digit and sometimes as the number one + another number. i. e. RAID 0 +1 or RAID 10, RAID 1, 5 or RAID 15. Because of different sources to identify these different settings, so do not try to identify all possible configurations and all possible acronyms for them. However, I try to explain what the most common type of RAID are, and how they may affect small business.
RAID 1 provides redundancy of the disk. Two identical hard drives installed, it is loaded with the operating system and all programs and data, other copies of the first unit consistently. This is known as a mirror and if a disk can not set the other unit to take over, without any data loss or downtime. The unit can not be replaced later, or even while the computer is running in some configurations (which would be the most expensive).
Mirroring is highly recommended for the operations of small businesses can not risk losing your data or your network closure while trying to retrieve data. The disadvantage is a reflection that the backup process slows the system a little '. If you are running a RAID mirror, the slowdown will be noticeable but not excessive. Reflection of hardware is almost imperceptible.
RAID 0 provides high performance, commonly called segmentation. Two (or more) identical units are installed and configured the RAID controller, either as a unit of about twice the size. When the system to read or write new data to the hard one, which reads or writes in place on both tape drives simultaneously. This reduces the time required to access or store data. The disadvantage of segmentation is that if one disk fails, you lose all your data. (Bummer!)
Shared commitment RAID 10 bands used by two sets of two units of speed, and thus reflects a broken record to another. The end result is faster than a normal mirror, and slower than a systematic recording broken. If one disk fails, the mirror band continues to operate. The disadvantage is that you need 4 or more units, driving up the cost.
RAID 5 is designed to resolve all issues. RAID 5 over three or more units of the process, give an extra band of recovery. Case of failure, the other units are able to reconstruct the data recovery information bandwidth. Again, this is often offered on a "Hot Swap Agreement" for the unity of deaths can be replaced and rebuilt without even rebooting the machine. Until recently, RAID 5 is available only in high-end SCSI configurations are not commonly found in the offices of the Small Business Administration. The only disadvantage of RAID 5 is that you lose about 1 / 3 of the units of the total capacity of the strip of recovery. (A small price to pay!)
RAID 6 is a new configuration to be promoted by Intel and others as the next generation. At this point I leave the benefits of RAID 6 to determine for yourself if you're interested. Read more here.
JBOD is "just a bunch of disks." Basically you have a RAID controller and use this technique to increase the number of units it has. There is no real function in RAID JBOD, in the traditional sense.
What makes a raid on a point of interest is the development of standard SATA II controller and the introduction of low cost SATA RAID integrated directly into the motherboard. In the past this was not unknown for RAID 0, 1, 0 +1, RAID 5, but only SCSI. Today you can buy a motherboard for $ 200 or less with SATA II RAID 0, 1 and 5 (and all combinations), built right into. Plus you can buy SATA II controllers from companies like Adaptec that allows you to run any SATA RAID configuration you want in almost all modern motherboards that you want.
The real kicker is that SATA drives are inexpensive. In the past, in a RAID configuration includes a SCSI hard disk that cost in the neighborhood of $ 500 each, now that will get about 146GB. So take a five-disk RAID 5, the solution as an example: five units of 146 GB hard drive @ $ 500 = $ 2500 you get about 487 GB of space. In addition to a SCSI RAID 5 controllers would be necessary, they are typically run over $ 350 to $ 700. Badge server grade controllers come with built in SCSI RAID 5, but the cost is $ 300 more easily than a motherboard without a driver. So here is the final cost between $ 2800 and $ 3200, or a minimum of $ 5. 75 GB.
Now let's look at the new SATA II RAID 5 configuration: you can buy a motherboard for less than $ 150 with onboard RAID 5 or RAID 5 SATA II for about $ 200 to $ 250. You can buy five 250-GB SATA II hard drives for something like $ 300. This would involve approximately 833 space. The final cost is then between $ 650 and $ 750 or $ 0. GB 78 on the bottom.
Now let's look at the cost of mirroring. If you have a Windows 2000 or higher can run a mirror server software that integrates with the OS, as I said there will be a significant slowdown of the system. Alternatively, you can run a mirror server hardware, or even a single desktop. The cost of two hard drives and a controller that arrive in the neighborhood of $ 300 to $ 350. SATA II RAID cards like the Adaptec 1420SA RAID 5 without function, are about $ 150, 500GB is about $ 100 each.
Consider what would happen if tomorrow we were working out and the hard drive fails. If you've read this site you will probably have a backup, but for how long it will be down while it was replaced the drive, reinstall the software backup and restore data? Have a backup, right?
Would you be willing to pay $ 300 to make sure you never lose your data and do not have to shut off power during a hard day of work due to a failure?
I (and not).
Sincerely. Here are a couple of website with more information on RAID. I remember some details, like the signs an agreement by one author to another, but the concept and execution are the same.
University of Massachusetts
Adaptec
Siig Sata Raid