Re: [ADMIN] H/W RAID 5 on slower disks versus no raid on faster HDDs

> Does anyone one if linux software raid 1 supports this method (reading from
> both disks, thus doubling performance)?
>

From memory of reading slightly old (1999) howtos, I believe that the answer is yes, at least for the md system. Not sure about LVM, or even if mirroring is supported under LVM.

I would guess that it shouldn't be too hard to test:

1) set up dataset on mirred system.
2) run pg_bench or one of the tpc benches.
3) fail one of the drives in the mirror.
4) run the test again.

If the read latency goes down, it should be reflected in the benchmark.

eric