Raid Levels Compared

[songokussm]

I have always used raid 5, for better or for worse.
Now that 6 and 10 are quite cheap, I thought i would check them out.
This is for the house storage. So mostly video and document files.

Disks: 4x Seagate Barracuda ST2000DM001 2TB 7200 RPM 64MB Cache
Controller: Highpoint 2720













I knew 0 and 5 would be the fastest, I just assumed that 10 would be faster then 6.
I hope this helps someone.
Your thoughts?

 

[Eug]

It's interesting to see that the random writes of RAID 5 are slower than single disk.

As for RAID 10 vs. RAID 6, the random read/writes are much faster with RAID 10.

BTW, I run just single disks (with several backups) for my 4-bay NAS, since I'm held back by the Gigabit network connection anyway. That means I max out at around 110 MB/s.

 

[smitbret]

Interesting how low the read times are from the RAID 1. I've never used a hardware RAID 1, but I had always heard that read speeds were great because it could pull from both mirrors at the same time.

 

[Phynaz]

It's interesting to see that the random writes of RAID 5 are slower than single disk.

This is expected, parity has to be read, calculated an re-written for each of the writes.

 

[Eug]

This is expected, parity has to be read, calculated an re-written for each of the writes.

Well, for some of the standalone units, RAID 5 random write speeds are quite decent.

 

[songokussm]

I decided to try out raid 10, mainly for the rebuild times. Raid 5 has always burned me more then once, with its 72 hour rebuild time (highpoint controllers are not fast).

So far my choice has been fantastic. Using Windows server 2012, I made 6 Virtual disks and their respective 6 targets. When having all 6 computers do a full backup their respective iSCSI drive, The average write was 20-35 mb/s each , or 120 - 200mb/s total. It took just two hours to backup all six computers, which was roughly 610gb total.

Secondly, I instigated two simultaneous failures. Rebuild took just over 10 hours.

Thirdly, The random access, is where the speed is at. It feels like i'm using a solid state drive. Its instant.