[mythtv-users] Replace backend 3.5 system disk with 2 2.5 raid1?

[Gary Buhrmaster]

On Thu, Sep 25, 2014 at 5:54 PM, Mike Rice <mikerice1969 at gmail.com> wrote:
> ... Would I notice any significant performance change?

"It depends".  Could get worse, could get better, depending
on your existing, and replacement drives, and your existing
utilization (if you are running at 80% I/O wait all day, then
any little change can make a huge difference).  All else being
equal (i.e. you are not changing filesystem integrity options
such as enabling barriers where before they were disabled),
the most likely potential issue is one of database
performance, because while you did not indicate where the
database was, it is most common that it is on the system
drive.  Typically, unless your database is especially badly
configured(*) you will probably not notice significant differences
due to average differences in drive performance, but your
mileage will vary.  They only way to be sure is to try it, and
monitor, monitor, and, of course, monitor.

Note that another option may be a SSD for your system
drive.  Even SSDs fail (so backups and a recovery plan
are always necessary), but they do not have the usual
failure modes of spinning rust, and smaller SSDs with
power failure protection are getting reasonably cheap.

Note that another option may be to pxe boot your BE.
No system drive to fail at all.

Lastly, it should be noted that protecting the system drive
may be goodness, but many people are just as worried
about their content drives.  Those drives can just as easily
fail as a system drive.  Be sure to invest your effort in
protecting what you value the most.  Everything fails.
Plan accordingly.

Gary

(*) Note that mysql/mariadb start with configurations
that are not especially good, although some packagers
override those configurations with better choices.  Be
sure to visit the wiki for database performance tuning tips.