Which one is better for my CentOS? Hardware RAID using Dell PERC 6 or Software RAID? [closed]

I would like to setup RAID 0 for my Dell 2900 server. Which one is better, using hardware RAID (using installed Dell PERC 6 controller) or software RAID? The RAID 0 is for database.

Hardware RAID is the only way to go, if your pockets allow.

See my other answer regarding raid to get the concept.

Dell PERC 6 although a real hardware raid is a "cheap" one. You should avoid that one and use software raid instead (if you can). If you end up using it as a hardware raid no worries, it is not that bad. Just do not expect too much from it (e.g. bad performance). There are also binary utilities that can be used to manage the controller from linux. They all suck compared to good hw raid or software raid.

My comment is based on my experince with a 1 or 2 generation older card. It could have been improved since, but I do not think so.

It depends on what you know and what you buy. Back in the day, I managed FC arrays on Sun servers with Veritas Volume Manager and software RAID. Things worked great and performance was excellent. I had a similar experience with AIX 4 servers a few years later.

Hardware RAID should be faster; but in reality the trashy RAID controllers that you often find negate that, and you'd be better off with a maintainable software RAID and lvm. Mr. Atwood's experience with the IBM ServerRAID 8k isn't an isolated incident. We had an incident where a defective RAID controller firmware forced us to visit over 400 remote locations to perform a manual upgrade.

If you don't know whether your RAID controller is junk or not, test, test, test.

This Stackoverflow posting talks about RAID layout for database servers. You should not use RAID-0 as it has no redundancy. RAID-0 is interesting for performance at the expense of everything else; you might use it on a video editing system (for example) but it is not appropriate for databases.

Linux has much better support for software RAID than Windows does. I would almost never recommend software RAID on a windows server. Linux is a different proposition. The software RAID on Linux is quite good and is certainly worth considering. On Linux, a fast CPU might result in better RAID performance than a slower RAID controller, but most SATA or SAS RAID controllers have fairly beefy RISC cores with hardware XOR units. Some even have multi-core CPUs clocked at more than 1GHz.

Most Dell PERCs are rebadged LSI or Adaptec controllers. One point to note is that they can take a battery backed cache, which is a feature that is not supported on software RAID. This gives you extra resilience to certain failure modes.

My suggestion would be to run some benchmarks with bonnie++ or something similar on both H/W and S/W RAID. If either configuration is noticeably faster go with that. However, if the server is currently in use and not causing any problems you may want to stick with your current configuration. The configuration is not likely to make enough of a difference to warrant rebuilding a server that is already in production.

Running a software RAID seems kind of like asking a airline pilot to fly the plane and serve drinks and peanuts to all the passengers at the same time :-)

In my opinion it's always better to use hardware that's dedicated to a specific task, thus I would choose the PERC RAID controller over the software RAID, regardless of the OS you are running.