[PVE-User] software RAID in 4.2

[Miguel González]

Dear all,

  I´m running Proxmox 4.2 onto a software RAID of 2 Tb SATA disks of
7200 RPM.

  I have set it up using OVH Proxmox installer with ext4. I have
realized that another server with just one SATA disk has writes of about
140 MB/s while this server with 2 disks has just writes around 40 MB/s:

  root at nyserver:~# hdparm -Tt /dev/sda

/dev/sda:
 Timing cached reads:   11800 MB in  2.00 seconds = 5903.84 MB/sec
 Timing buffered disk reads: 136 MB in  3.17 seconds =  42.94 MB/sec

root at myserver:~# hdparm -Tt /dev/md4

/dev/md4:
 Timing cached reads:   11356 MB in  2.00 seconds = 5682.49 MB/sec
 Timing buffered disk reads: 132 MB in  3.10 seconds =  42.52 MB/sec

 I´m running 4.4.15-1-pve kernel.

 Is there any way to improve the performance of writes?

 Thanks!

 Miguel