RAID technology is almost one that that can guarantee good data consistency and prevent data lost. Therefore it became standard when you need to feel yourself in safety. Additional plus of this technology is possibility to speed up data access when you use big arrays of disks. But problem is that not every RAID array can give confidence in your data safety. Working with a lot of raid arrays I found that some solutions may create more problems for you than if didn’t use RAID at all. In this post I want to analyze the pros and cons of software and hardware RAIDs.
Hardware RAID’s pros:
- Hardware RAIDs is good when you have important system that costs a lot. In that case you will probably get quite reliable raid controller that will work for longer and really give you confidence about your data.
- Good hardware raids are fast and you can expect that will not loose speed if you will combine a lot of hard drives.
- If one of your hard drives will crash than rebuilding of the array won’t create any load on your main CPU or other hardware in your server.
Hardware RAID’s cons:
- If have to save your money than selecting hardware solution is not a good decision. The reliability of chosen raid card may be hard to check and you will have very risky solution.
- Reliable cards cost a lot of money.
- If your card will ever fail and you will have to replace it you may find out that to buy the same card is not an easy task. The manufacturer may cease its production or simply disappeared. The problem that you can’t simply buy another card of other manufacturer. The data structure on your hard drives combined in RAID very specific for each manufacturer or even RAID cards.
- Managing options of hardware RAIDs very specific for each card and may be very limited.
Software RAID’s Pros:
- They are cheap
They simply have no cost because they use your server cpu and software that you’ve already buy or free software as Linux or FreeBSD. - They are quite reliable because they have been tested by a lot of people that use them in their systems for ages. And to my opinion the number of them greatly overcomes of those who use hardware solutions.
- You always have a lot of tools and options for managing you raid arrays.
- You will not have any problem if your motherboard or any other hardware will fail. You will simply replace it and will proceed running your system. Our you can move your hards on other hardware and easily launch the stumbled system.
Software RAID’s Cons:
- They consume your CPU to replicate data on other hard drives. So if you have to create an array with a lot of hard drives than select hardware solution. But in that case the hardware solution will worth it’s cost.
- If your software array containing a lot of drives will fail it may be hard and long task to recreate the whole array.
- You will not have any warranties from manufacture for failed array
Conclusion:
So if you plan to use a few hard drives in your array it’s better to choose software solution. It’s cheap, reliable and easily repairable. Another case if you have big system with hard load and a lot of hard drives. The software solution will fail in this case and you have the only way to chose hardware solution.