On Fri, Jun 24, 2022 at 08:35:31AM -0400, John Mellor wrote:
On 2022-06-23 23:04, ToddAndMargo via users wrote:
> Any of you guys know of a PCIe card that will do
> hardware RAID 1 with two NVMe drives?
>
> I have found some, but they are way to elaborate,
> and as such, way too expensive.
Maybe you have a weird hardware requirement that explains the question, but
why do you want a RAID-1 card?� Software RAID is much cheaper, faster, uses
less power and is considerably more reliable.� If you run BTRFS or ZFS, then
it is also easier on the drives, and recovery times are hundreds of times
lower than what you can do with hardware.� That translates directly into
hundreds of times better reliability numbers.� Best of all, you do not need
matching drives or drive sizes to implement RAID-1.� For a long time now,
the only reason to run hardware RAID has been underneath back-level versions
of Windows or VMware.
When I last tried about two years ago, using RAID-5 via LVM with no file system
I was unable to come close to maximum performance for sequential only writes,
where you do not need to read data off of the disks - it was still reading and
writing.
I couldn't find any details on how to get this to work or if it was possible.
I tried tuning various settings (I can't recall specifics, but generally
increasing the memory it uses) but with little change in performance.
-- Patrick