RAID stands for Redundant Array of Independent Disks.
In this case 'array' means a bunch of disks working together for two main reasons—either to keep your data safe, or provide you with faster data access.
Your data is spread accross all the disks used in your RAID system. The data is distributed among the disks in different ways according to the RAID level you have.
How does a RAID system keep your data safer?
Having your data spread across more than one disk means that, if one of your disks fails, your data is still safe on the others. If you have all your data on a single disk and it fails you've lost the lot.
Why would using RAID system make data access faster?With all RAID levels except RAID 0, parts of a single file are spread across more than one disk. Because of this, the different parts of that file can all be accessed at the same time, speeding up read and write speeds considerably. It's like using a multi-lane highway rather than a single lane road—on the highway cars are spread across different lanes and can get to their destination much faster.
When you create a RAID array using SoftRAID, our software keeps track of which disks are in your array, and where all your data is.
SoftRAID provides 5 RAID levels:
In order to use space on different disks, SoftRAID creates what's called a RAID volume.
You can think of a volume as a container for your files. Each disk in your RAID volume contributes some of its space to that container.
With RAID 4, 5 and 1+0 (aka 10), you can lose a disk and carry on working—though SoftRAID will warn you well in advance if your disk looks likely to fail. With RAID 0 you'll get lightning fast disk access, though your data won't be protected against disk failure.
The great thing about SoftRAID is that, because you can have more than one RAID volume on your disks, you don't have to choose between speed of access and data safety: you can have both!
A SoftRAID RAID system allows you to 'bundle' up to 16 disks to work together—so you get faster data access and data safety, protecting you against disk failure.*
SoftRAID RAID Stripe Volume
RAID 0 stripe volumes provide the fastest possible access to your data. However they won't protect your files against disk failure—when a disk fails* on a stripe volume, you will lose all the files on the entire volume. RIAD 0 should only be used for temporary storage.
In order to achieve lightening fast access speeds, stripe volumes spread your data across 2 or more disks—each disk contains just part of your data. They're called 'stripes' because your files are, in effect, 'striped' across all the disks in your volume—ie. parts of a single file are spread across all the disks.
RAID 0 allows you to read to, and write from, all the disks in a volume at the same time, so each part of a single file can be accessed simultaneously. If you have four disks in your RAID 0 volume you'll be reading that file approximately 4 times as fast, quadrupling the amount of data you can access in a given time. It's like using a multi-lane highway rather than a single-track road—the highway allows more vehicles through at any one time.
RAID 0 is not a good solution for long-term storage as it won't protect you against disk failure. If any disk fails in a RAID 0 volume all your data is lost; because single files are split between disk, any failed disk will take part of that file away with it and the file can't be rebuilt.
SoftRAID Mirror Volume
RAID 1 mirror volumes are the safest RAID you can choose. You should use RAID 0 whenever you have critically important information to store.
RAID 1 are known as mirrors, because each disk in your RAID 1 system contains a volume with identical data; ie. a mirror. As you work on disk A, SoftRAID updates the volume on disk B to be an exact copy of disk A. If you have more than one mirror disk (which is recommended), the extra disks will also be updated so they too are an exact copy of disk A.
With a mirror volume, if a disk fails, you can keep right on working as the remaining disk, or disks, will take over. Because SoftRAID constantly ensures that the data on all your disks is identical, you won't lose a beat…or any data!
For complete reliability, create a RAID 1 system with your main disk, plus 2 or more mirrors. Extra mirror disks can be removed and stored off-site, in different locations, for extra safety. Whenever you plug one of those disks back in, SoftRAID will recognise it as a mirror disk, work out what has changed and quickly update the data so it's once again identical to your working disk. In addition, SoftRAID uses a system which rebuilds mirror volumes incredibly fast, unlike many other RAID 1 systems.
Mirror volumes are generally slower than other RAID volumes, because they are constantly ensuring that each volume is an exact copy of the volume on your working disk. One way to create a faster mirror volume is by using an SSD for your working disk, and a mechanical hard drive for your mirror volume. The SSD gives you incredibly fast read speeds and the hard drive gives you safer storage, protecting your mirrored files from disk failure. (SoftRAID has complete support for SSDs)
You can read more about the best uses for RAID 1 volumes here
You can read a more detailed explanation of how RAID 1 works here
SoftRAID RAID 4 Volume
SoftRAID RAID 5 Volume
RAID 4 and RAID 5 volumes give you the best combination for maximizing disk space, fastest access speeds and protection against disk failure. While other RAID levels may give you faster data access, or fail-safe data protection, no other RAID level combines speed, space and safety so well.
With RAID 4 and RAID 5, you'll be able to keep working even after a disk gets an error or fails completely. You won't lose hours retrieving data from the cloud or a backup disk.
How do RAID 4 and RAID 5 allow you to carry on working even with a failed disk? With RAID 4 & 5, each disk contains either a section of a data file, or a piece of 'parity' data, calculated (by SoftRAID) from your actual data. If the disk storing a segment of a data file fails, the parity data is used to reconstruct the missing piece of that file.
RAID 4 and RAID 5 are great if you need to frequently access (read) a lot of fairly small files. However they are much slower at writing many small files to disk, since they have to create 'parity data' for each file. If you need to write many small files, we suggest you use RAID 1+0
Use RAID 4 if you are using SSDs for your RAID system. If you are using mechanical hard drives RAID 5 is best.
You can read more about the best uses for RAID 4 & 5 volumes here
SoftRAID RAID 1+0 Volume
If you have 4 or more disks for your RAID volume, this is the best RAID solution there is.
RAID 1+0 combines the speed of RAID 0 stripes, with the safety of RAID 1 mirrors so it's ideal if you need both super fast data access and increased data safety.
RAID 1+0 volumes are made up of pairs of disks. Each pair, called a mirror pair, contains two disks which have identical information. If one disk in a mirror pair fails, the volume can keep reading and writing your files because it will use the other disk in the mirror pair instead.
The increased speed of RAID 1+0 volumes comes from striping mirrored pairs of disks together. Instead of striping together individual disks, like a stripe (RAID 0) volume, a RAID 1+0 volume treats each mirror pair just like a single disk of a stripe volume. RAID 1+0 volumes can only be made with even numbers of disks and require at least 4 disks. With SoftRAID, you can create RAID 1+0 volumes with up to 16 disks ie. 8 mirrored pairs.
You can read more about the best uses for RAID 1+0 volumes here
You can read a more detailed explanation of how RAID 1+0 works here
* All disks fail at some rate. Good disks fail at a rate of about 3% a year, bad ones at 25% a year or more. Even SSDs (Solid State Disks) fail at about the same rate.
After more than 500 hours of testing three popular disk brands, SoftRAID staff found - though most worked fine - one brand and model had a 33% failure rate. Your disk could be one that fails at a 3% rate, a 25% rate, or even higher; you won't know till it happens.
Even if you have one of the safer disks, over time, and with more disks, risk of failure increases to as much as 25%. This is why you should only use a RAID 0 volume as part of a larger backup system. If all your data is only on a RAID 0 volume, it's unprotected; if your disk fails, you could lose it all. top…