Alan Cox wrote:
The raw read speed on a RAID1 array is the speed of a single drive. The
No. A smart raid1 driver will use both source disks. The raw write speed
is that of the slowest drive (plus overhead).
Does this mean that the Linux software RAID is not smart, or there's a
way to make it actually do this? Current FC[678] doesn't seem to be
"smart."
RAID 10 gives you better write throughput which on a modern PC normally
means that with PCI Express your bridge/memory bandwidth becomes the
limit.
This is what I measure running an E6600 CPU and 3xSeagate 320 with
Recent FC7 kernel. All reads and writes to the raw array using dd, 1MB
buffer, 1GB i/o to/from /dev/{zero,null} for raw speed. Units are MB/s,
64k chunks, speed as reported by dd.
RAID lvl read write
0 110 143
1 52.1 49.5
10 79.6 76.3
10f2 145 64.5
raw one disk 53.5 54.7
Alan
--
Bill Davidsen <davidsen@xxxxxxx>
"Woe unto the statesman who makes war without a reason that will still
be valid when the war is over..." Otto von Bismark
