[CentOS-virt] LVM mirror database to ramdisk

[NightLightHosts Admin]

On Fri, Jan 22, 2016 at 4:54 PM, Ed Heron <Ed at heron-ent.com> wrote:
>   Yes, but it isn't that simple.  One copy of the mirror would be on a
> physical disk.  The other copy of the mirror would be on RAM disk.
> Since data in RAM doesn't generally survive reboot, the RAM piece would
> need to be turned off before shutdown and created on startup.
>
>> Is there something about LVM mirroring that can handle disks of
>> different speeds?
>
>   With newer LVM, there appears to be some settings that might help with
> that a bit.  With this older verion, I'd be hoping that the next
> available disk would handle each request.  If the physical disk takes
> longer to deal with the writes, the RAM disk might be the one that is
> available most of the time.
>
>   I'd much prefer a method of pre-filling a 35G cache but I saw a
> reference to creating a disk mirror in RAM and decided to explore it.
>

Can you post the results of your test when you get it working?