RFC: Suggesting ZFS "best practices" in FreeBSD

[Ronald Klop]

On Tue, 26 Feb 2013 08:33:58 +0100, Daniel Kalchev <daniel at digsys.bg>  
wrote:

>
>
> On 25.02.13 18:44, Karl Denninger wrote:
>> On 2/25/2013 8:31 AM, Tom Evans wrote:
>>> Using GPT labels is easy to do, and provides a cast iron guarantee
>>> that your disk will not EVER be mistaken for a different drive.
>>>
>>> I put a GPT label on the drive, and then write it in permanent marker
>>> on the top of the drive and on a sticky label that is stuck on the
>>> front of the chassis. The disk label never changes in its lifetime, so
>>> you only get issues if you insert a drive without labelling it first.
>>>
>>> Cheers
>>>
>>> Tom
>>>
>> Listen to this man.  Either do it in gpart or do it with glabel
>> (depending on where you want it to show up); once done the drive will
>> always have the same name in the device tree no matter what slot it
>> shows up in.
>>
>> Then stick that label on the front of the drive carrier, and you never
>> have this problem.
>>
>> Do that or suffer.  Your choice.
>>
>
> I can only second this advice.
>
> Learn to make your setups as generic as possible. Wiring down device  
> names using CAM etc, only complicates matters, at least because that  
> knowledge is contained within the system you boot, not the drive. If you  
> boot from an "recovery media", all of your "fine crafted" CAM wire-down  
> system will be gone and you will suffer. You will suffer exactly at the  
> moment when you need those labels most. Not wise.
> Yes, Jeremy, there is always the first time.
>
> Both glabel and GPT labels do the trick. Both behave differently and  
> depending on your habits and intended usage one or the other is good.  
> Just don't be inclined to use both at the same time. My personal  
> preference as of later is GPT labels.
>
> By the way, "glabel" is a generic term in FreeBSD. It refers to all  
> label types, including those created with glabel, gpart and  
> newfs/tunefs. The later are not really "geom labels", these are volume  
> labels, but glabel is smart enough to detect/report them, even if it  
> can't manipulate these labels. I don't find the glabel documentation all  
> that confusing.
>
> Daniel

I second that.

Ronald