Low disk system performance in linux, reasons?

Question

linux

Hello,
I'm not very strong in * nix, but I set some task and ran into a problem while solving it.
The task is that there is an
HP Proliant DL360e Gen8 server, it has 8 disks: 4 SSDs assembled in RAID 1 + 0, and 4 regular terobyte HDDs in RAID 5. The
space in the RAID 5 array has run out.
The RAID controller is used HP Dynamic Smart Array B320i, since it does not know how to change the size of the array on the fly, the scheme of work turned out to be as follows:
1) I connect a regular SATA 5TB to the ODD port.
2) I copy the data from the array there
3) I delete the array
4) I change hards
5) I create a new array
6) I transfer the data to a new array.
At the second stage, a problem arose: an extremely low data transfer rate.
Copying goes at a speed of ~ 30 megabytes per second. At first I thought it was because the disc was inserted into the ODD.
But I tried to copy to /dev/null from both hard and ssd arrays. All the same, the speed is around 30 megabytes.
Actually the question is, because of what it can be, and what to do, how to fix it?
Linux Ubuntu 14.04.1, kernel 3.19.0-32-generic is installed on the server

Answer 1

Stop using Linux 2.4! It is 10 years outdated.