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Date: Tue, 12 Aug 2014 08:00:34 -0600 (MDT)
From: Warren Block <wblock@wonkity.com>
To: RW <rwmaillists@googlemail.com>
Subject: Re: gpt label missing after adding gjournal
In-Reply-To: <20140812131123.5a0f79fb@gumby.homeunix.com>
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On Tue, 12 Aug 2014, RW wrote:

>
>
> I followed Warren Block's howto:
> http://www.wonkity.com/~wblock/docs/html/disksetup.html
> to partition a new drive like this:
>
> $ gpart show -l ada1
> =>        34  5860533101  ada1  GPT  (2.7T)
>          34           6        - free -  (3.0K)
>          40        1024     1  gp0boot  (512K)
>        1064         984        - free -  (492K)
>        2048     8388608     2  gp0root  (4.0G)
>     8390656    33554432     3  gp0swap  (16G)
>    41945088     4194304     4  gp0var  (2.0G)
>    46139392   100663296     5  gp0usr  (48G)
>   146802688  1468006400     6  gp0home  (700G)
>  1614809088  4245723136     7  gp0rest  (2.0T)
>  5860532224         911        - free -  (456K)
>
> and then I created gp0home.journal and  gp0rest.eli.journal
>
> when I rebooted gp0home was missing from /dev/gpt
>
> $ ls  /dev/gpt
> gp0boot gp0rest gp0root gp0swap gp0usr  gp0var
>
> The gjournal partition is recognized as
> /dev/ada1p6.journal and can be mounted, but I can't mount it with the
> gpt label.
>
> Anyone know what's going on?

Mounting a device, or that device being used by another device, can 
cause the labels to be hidden.  The gp0home.journal device is using 
/dev/gpt/gp0home, so that device label "withers" and disappears.  If you 
unmount /dev/ada1p6.journal, does /dev/gpt/gp0home become visible again?