[mythtv-users] Some master/slave backend advise required

[Jean-Yves Avenard]

On 3 June 2014 15:35, Johan Van der Kolk <johan.vanderkolk at gmail.com> wrote:

> For those who understand bonnie ( i don’t). This is a command line taken
> from https://calomel.org/zfs_raid_speed_capacity.html.
> I ran it on my zfspool.
>
> Version  1.97       ------Sequential Output------ --Sequential Input-
> --Random-
> Concurrency   1     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block--
> --Seeks--
> Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec
> %CP
> Zolder-server   80G           318688  37 136544  25           269337  20
> 38.6   2
> Latency                        4301ms    1176ms               549ms
> 658ms
>

beware with Bonnie, more often than not (and that's certainly the case
with the calomel review), due to the arguments provided what they are
really testing is the cache and memory speed, and rarely the actual
raw I/O to the disk.

136MB/s on 6 disks in RAIDZ2 is rather low, much lower than I would
have expected (mine gives me over 400MB/s of raw I/O under similar
conditions)