RFC: Suggesting ZFS "best practices" in FreeBSD - mapping logical to physical drives

[Michael DeMan]

Except that does not work when the technician just needs to know which darn physical disk to remove/replace by looking at the front of the box?

I think possibly on this thread we are discussing some major topics - all of which would be good categories within a 'best practices' document?

#1.  Best practices for design.
#2.  Best practices for maintenance (logical)  - ZFS 'halt scrub' would be awesome), when to scrub, etc - how to label your disks, blends into #3...
#3.  Best practices for physical maintenance - i.e at the end of the day ZFS theoretical break down if somebody can't look at the front of the machine and figure out which disk was the bad one?

Maintenance (in my definition) including the scenario where the guy changing the disk is not necessarily a FreeBSD wizard and all-knowledgable about gpart, gnop, glabel and such?

Some idea that whoever designs, builds, deploys and then maintains the physical server over a 3-7 year service life - that one person is supposed to do all of that does not work well either for small businesses or large businesses?

Sorta off topic on this - sorry.




On Jan 23, 2013, at 12:58 AM, Peter Jeremy <peter at rulingia.com> wrote:

> On 2013-Jan-22 18:06:27 -0800, Michael DeMan <freebsd at deman.com> wrote:
>> # OAIMFD 2011.04.13 adding this to force ordering on adaX disks 
>> # dev.mvs.0.%desc: Marvell 88SX6081 SATA controller 
>> # dev.mvs.1.%desc: Marvell 88SX6081 SATA controller 
>> 
>> hint.scbus.0.at="mvsch0"
>> hint.ada.0.at="scbus0" 
> ...
> 
> That only works until a BIOS or OS change alters the probe order and
> reverses the controller numbers.
> 
> The correct solution to the problem is gpart labels - which rely on
> on-disk metadata and so don't care about changes in the path to the
> disk.
> 
> -- 
> Peter Jeremy