[CentOS] ssacli start rebuild?

Thu Nov 12 00:00:07 UTC 2020
John Pierce <jhn.pierce at gmail.com>

On Wed, Nov 11, 2020 at 3:38 PM Warren Young <warren at etr-usa.com> wrote:

> On Nov 11, 2020, at 2:01 PM, hw <hw at gc-24.de> wrote:
> >
> > I have yet to see software RAID that doesn't kill the performance.
> When was the last time you tried it?
> Why would you expect that a modern 8-core Intel CPU would impede I/O in
> any measureable way as compared to the outdated single-core 32-bit RISC CPU
> typically found on hardware RAID cards?  These are the same CPUs, mind,
> that regularly crunch through TLS 1.3 on line-rate fiber Ethernet links, a
> much tougher task than mediating spinning disk I/O.

the only 'advantage' hardware raid has is write-back caching.

with ZFS you can get much the same performance boost out of a small fast
SSD used as a ZIL / SLOG.

-john r pierce
  recycling used bits in santa cruz