I have a CentOS server with 2 hard drives configured to use LVM over RAID1.
How do I benchmark my hard drive? As seen in this question, I have used the following commands:
# check read performance sudo hdparm -Tt /dev/sda # check write performance dd if=/dev/zero of=/tmp/output bs=8k count=100k; rm -f /tmp/output
But I got roughly the same figures as I got on a single disk, before configuring the RAID array. Now I figured that I should be explicitly using the LVM drive instead of /dev/sda and /tmp/output. I must have done something wrong here, as the system stopped finding crucial system files such as yum. I failed to write down the exact commands I used and I had to reinstall the system at this point.
So, what commands should I use to check disk perfomance of LVM drive? And, most important, what kind of commands should I not use?