[zfs-discuss] recommendations for a 50 TB zpool?

Ulli Horlacher framstag at rus.uni-stuttgart.de
Sat Nov 3 20:32:04 EDT 2018

On Sun 2018-11-04 (00:13), Gordan Bobic via zfs-discuss wrote:
> IMO, disks much over 4TB are bad news. I suggest you stick with 4TB disks.

The server host has not so many disk bays.
Why are disks bigger than 4 TB bad?
Because of seek times?

> Avoid shingled or helium filled disks, or those under 7200rpm.

Avoiding SMR and <7200rpm is evident, but why are helium filled disks a

> Consult last few years worth of Backblaze statistics when choosing the
> disk brand and model to get.


HGST looks like a good choice.

> I concur with you that RAIDZ2 is a reasonable choice for reliability, but
> bear in mind that while this will be a reasonable choice for sequential
> workloads, performance will be very poor for random read workloads (with
> 7200 rpm disks, you will get 120 IOPS per vdev).

A F*EX server does mostly sequential reads and writes, there are no
databases or something like this.

Ullrich Horlacher              Server und Virtualisierung
Rechenzentrum TIK         
Universitaet Stuttgart         E-Mail: horlacher at tik.uni-stuttgart.de
Allmandring 30a                Tel:    ++49-711-68565868
70569 Stuttgart (Germany)      WWW:    http://www.tik.uni-stuttgart.de/
REF:<CAMx4oe2QBmd5oPCr1PrygEo7P-7C9eUFeTYUcL0DvhbHNcoAHA at mail.gmail.com>

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