On 6/9/2011 1:26 PM, John R Pierce wrote:
On 06/09/11 2:24 AM, Emmanuel Noobadmin wrote:
Alternatively, if I mdraid mirror the existing disk, would md be smart enough to read using the other disk while the first's tied up with the first process?
that woudl be my first choice, and yes, queued read IO could be satisfied by either mirror, hence they'd have double the read performance.
next step would be a raid 1+0 with yet more disks.
mdadm is good, but you'll never get double the read performance. Even on our 3-way mirrors (RAID 1, 3 active disks), we don't come close to twice the performance gain.
RAID 1+0 with 4/6/8 spindles is the best way to ensure that you get better performance.
Adding RAM to the server so that you have a larger read buffer might also be an option.