Which RAID setup & hard drives do you use, and why?

<font color="yellow">Which RAID setup & hard drives do you use, and why (or do you not use RAID at all)?</font>

My large forum server currently uses a SCSI RAID 5 array with 3 10,000 RPM drives. However, I am starting to regret that choice as I understand the performance of RAID 5 writes is not really any better than a stand alone drive. RAID 5 arrays are fast at reads and there is hardware failure protection of course. I now wish I went with RAID 0+1 or a RAID 10 array, which improves both read and write performance and includes fault tolerance. Does anyone know the difference between the two (0+1 vs 10)?

I've decided to add a single large 4th SCSI drive outside the array for daily backups and possibly log files. Of course, I do regular external backups as well. It seems the log file creation (over 2GB every few days) is one of the most intensive write operations that generates a significant constant load -- especially since RAID 5 is not as fast at writes. If I offload those less important files to a secondary drive I'm hoping it will take a lot of the writes off the array. Plus, backups on my server are the single biggest load generator, take several hours, and slow down the forum more than anything else. I believe backing up from the array to another drive could reduce the load and significantly and greatly decrease the time it takes.

-vissa

[dbembibre]

I have two 2X 73 GB SCSI in raid 1

[BoardTracker]

Depends what you will use it for but generally RAID10 is a good choice.. safer and faster than raid5 although costs a bit more.

We used to use raid5 on a fileserver with a fairly big array (nearly 5TB in 24 disks) but performance sucked and when so many disks are involved things can and do go wrong. We switched to raid10 and its all so much better.. server loads are down, traffic is up and data is safer.. everyone is happy.

[silvrhand]

New cards in the market are removing this problem, see the Netcell SPU for an example of that.

"Revolution storage processing cards feature a revolutionary 100% hardware-based 64-bit RAID engine that offers a mainstream RAID solution with the simultaneous benefits of both RAID 0-class performance and RAID 5-class data protection."

Originally Posted by MarcoH64

RAID 5 will very likely perform less then RAID-10 for write operations, this even get worse when adding more disks (reason, a checksum of the sector for all disks must be calculated and written, the more disks, the more sectors to calculate). Some of the performance downgrade can be reduced by proper configuration and write back cache.

RAID-10 will (depending on the hardware implementation of the RAID-controller) be faster with writes simply because there is no checksum to calculate.

What performs better greatly depends on your Read/Write ratio and how sequential the data is that is read. For a board, writes are often much lower then reads, so the performance on writes should not have such a big impact.

http://tweakers.net/reviews/557/25

There is a great review there, and look at the mySQL results, this is in a mixed environment as well, so lots of read and writes where I'm mostly in the 25-30% write for our forums.

This is a very thorough test and the Areca ARC-1160 with 1GB cache shows a huge lead over most other cards in the test.

RAID 10 will beat RAID5 in HEAVY write tests, but in our scenario RAID5/10 arrays are very close to the same, at least for me in my < 30% write scenario. Your mileage MAY vary, I generalized a bit too much in my earlier posts.

FYI also:

The new ARC-1220/1230/1260 uses Intel? IOP333 I/O processor. So XOR calculations should be even better improving database performance. The review above was on the 1160, which uses an older I/O processor.

[vantage255]

with 8 or more drives, they are close. The big speed issue that most people here will see isnt a processor based issue though. Most people dealing with hosting on a non enterprise level will have issues due to their raid arrays being only 3 or 4 drives. As this forces 2 writes onto one drive for every write to the array. This hurts write performance badly.

With enough drives raid5 is certainly a good choice. And a lot of buffer help. some EMC sans I work with have 32 or 64 GB of buffering. that makes a huge performance boost.

[silvrhand]

EMC/Netapps are great, wish I could afford to run MySQL on that hehe.

Originally Posted by vantage255

with 8 or more drives, they are close. The big speed issue that most people here will see isnt a processor based issue though. Most people dealing with hosting on a non enterprise level will have issues due to their raid arrays being only 3 or 4 drives. As this forces 2 writes onto one drive for every write to the array. This hurts write performance badly.

With enough drives raid5 is certainly a good choice. And a lot of buffer help. some EMC sans I work with have 32 or 64 GB of buffering. that makes a huge performance boost.

[BoardTracker]

EMC/Netapps are great, wish I could afford to run MySQL on that hehe.

I've had a netapp before and its only great until it comes time to buy another shelf of disks and then they slap you with the $25k bill.. :ermm:

These days I'd go for a SATABlade or some other Nexsan servers.. the SATABeast is truely a beast.

[vantage255]

I am buying up Sun D-1000 and A-1000 drive arrays at the moment. cheap on ebay and they are solid hardware. Good for hosting.

EMC is nice... but not the price point you want for hosting.

[DevilYellow]

My webserver runs 10k dual SATA drives (RAID 1) for backup purposes.

I am going to start building a deciated DB server. The DB is over 1GB as it sits and I dont see it going anywhere but up.

Right now my vauge plans were just dual dual-core Opterons, nice Tyan mobo, 4GB RAM, and some sort hard drive solution.

What would be best? U320, SAS, or SATAII?

For a DB server RAID 10 would be the best for performance and
redundancy?