RAID 10 slower than RAID 1

[jakehaas]

Hello,

 

Need some help with a weird issue I'm running into...

 

I have 2 Dell R900 servers both with a H700 raid controller. One has 2 Samsung pro SATA SSDs in RAID 1 and the other has 4 in RIAD 10.

 

On the RAID 1 I am consistently getting much faster disk write speeds than on the RAID 10. I don't believe this should be the case as the whole reason I chose raid 10 was for the better performance over raid 1.

 

Both systems are running the same version of ubuntu. I have tried fresh installs to make sure its not a software issue.

 

On the RAID 1:

dd if=/dev/zero of=/home/jake/test bs=1M count=2k conv=fdatasync

2048+0 records in

2048+0 records out

2147483648 bytes (2.1 GB, 2.0 GiB) copied, 7.80604 s, 275 MB/s

 

On the RAID 10:

dd if=/dev/zero of=/home/jake/test bs=1M count=2k conv=fdatasync

2048+0 records in

2048+0 records out

2147483648 bytes (2.1 GB, 2.0 GiB) copied, 12.1799 s, 176 MB/s

 

I have been troubleshooting this for a while and hoping someone here has run into something similar and could lend a hand.

 

Many thanks!