what is the best Hammer setup to taclke the bitrot problem + DRP

[Tomohiro Kusumi]

In short, hammer doesn't solve (or fix) what you call bit-rot.


2016-12-26 20:30 GMT+09:00 vincent delft <vincent.delft at gmail.com>:
> Hello,
>
> First of all I'm new to DF.
> Thanks for the nice install process. It's a quite easy to have DF running.
> But my concerns are more linked to HammerFS.
>
> My context is the following:
> - I would like to have a NAS system running on a small machine: 4GB RAM
> having a celeron CPU of 1.6GHz.
> - This NAS host +- 700GB of data
> - I plan to install 1 disk of 1TB in the NAS and keep a second disk of 1TB
> outside the NAS for DRP reasons.
> - I'm looking for a solution tackling the bit-rot problem.
>
>
> Concerning HammerFS, I've still read lot of DF manuals, pages, ... :
>
> http://lists.dragonflybsd.org/pipermail/users/2015-March/207585.html
> http://lists.dragonflybsd.org/pipermail/users/2006-June/297848.html
> http://lists.dragonflybsd.org/pipermail/users/2016-March/228659.html
> http://lists.dragonflybsd.org/pipermail/users/2015-January/311705.html
> https://www.dragonflybsd.org/hammer/
>
> So basically, I've understood that I must install DF on a small SSD disk and
> will dedicated the 1TB disk to HammerFS.
>
> But I have some questions:
> - What must be the setup of HammerFS to solve "bit-rot" ? Should it be Raid1
> or Raid5, ... ? Can it be done on 1 physical disk (thus 2 filesystems) ?
> Should it be 2 PFS in 1 HammerFS located on 1 slice or should I create 2
> slices on the disk?
>
> - For DRP reasons, how can I perform a backup on an external disk ? (the
> disk is only connected 1x per month on the NAS). Should I do a "dd" ? should
> I use the master-slave concepts ? Should I use cpdup ?
>
> Many thanks for your replies.
>
> Vincent
>
>