gpart labels - why arent't some showing up in /dev/gpt/?

Wed May 2 09:11:42 UTC 2012

On Wed, May 2, 2012 at 9:46 AM, Peter Maloney
<peter.maloney at brockmann-consult.de> wrote:
> I have the same problem. Any time you boot off a CD/DVD and use import -f
> (and then don't export), or I guess use import -f a pool from anywhere, it
> does that. I don't know any non-zfs causes for the problem.
>
> Here are some relevant /boot/loader.conf settings (I don't know how accurate
> the comments are... I wrote them myself, without fully testing them):
>
> # Setting this to 0 will get rid of the /dev/gptid directory and you will
> see your /dev/gpt directory again if it bugged out and gpt labels
> disappeared.
> #kern.geom.label.gptid.enable=0
>
> # Not sure what this does; I assume it means to forget about /dev/gpt/* and
> probably either show gptid (if not disabled above) or the original device
> name (eg. da0p2)
> #kern.geom.label.gpt.enable=0
>
>
> However, that is a lame workaround, disabling a feature to get another back.
> I would love to see a good fix.
>
>
>
> On 05/02/2012 08:39 AM, Andrew Reilly wrote:
>>
>> Hi there,
>>
>> I like being able to label my drives and partitions with gpart,
>> so that I can (putatively) replace drives or move them around
>> or have the new ata drivers move them around for me, and still
>> have fstab find them.
>>
>> So, for example, I have (in fstab):
>> /dev/gpt/root           /               ufs     rw,async,noatime 1      1
>>
>> Which derives from an appropriate label on ada2p1:
>> Geom name: ada2
>> modified: false
>> state: OK
>> fwheads: 16
>> fwsectors: 63
>> last: 117231374
>> first: 34
>> entries: 128
>> scheme: GPT
>> Providers:
>> 1. Name: ada2p1
>>    Mediasize: 65536 (64k)
>>    Sectorsize: 512
>>    Stripesize: 0
>>    Stripeoffset: 17408
>>    Mode: r0w0e0
>>    rawuuid: 356aefc1-92a7-11e1-ae3f-00270e0fb8e9
>>    rawtype: 83bd6b9d-7f41-11dc-be0b-001560b84f0f
>>    label: bootme
>>    length: 65536
>>    offset: 17408
>>    type: freebsd-boot
>>    index: 1
>>    end: 161
>>    start: 34
>> 2. Name: ada2p2
>>    Mediasize: 60022325248 (55G)
>>    Sectorsize: 512
>>    Stripesize: 0
>>    Stripeoffset: 131072
>>    Mode: r1w1e2
>>    rawuuid: 9995b354-92a7-11e1-ae3f-00270e0fb8e9
>>    rawtype: 516e7cb6-6ecf-11d6-8ff8-00022d09712b
>>    label: root
>>    length: 60022325248
>>    offset: 131072
>>    type: freebsd-ufs
>>    index: 2
>>    end: 117231359
>>    start: 256
>> Consumers:
>> 1. Name: ada2
>>    Mediasize: 60022480896 (55G)
>>    Sectorsize: 512
>>    Mode: r1w1e3
>>
>> Back when I first built this computer, I similarly labelled the
>> four freebsd-zfs partitions on my four main spinning disks, with
>> the intention that I could use these names in a non-confusing
>> way in subsequent zpool create commands.  This did work *once*,
>> but after using the /dev/gpt/raidz0... names to create a raidz
>> tank, they disappeared from /dev/gpt, and the names that showed
>> up in zpool status output were the long strings of digits from
>> the /dev/gptid/ directory.
>>
>> This week I had to blow my raid array and start from scratch,
>> after zpool scrub proved itself incapable of fixing or removing
>> the corruption that I have mentioned here earlier.  Even after
>> clearing the disks of their zpool, the gpt names did not show up
>> under /dev/gpt, so I have had to rebuild my zfs array with
>> old-school partition names, like ada0p1 and so on.  This does
>> work, but it seems a bit sub-optimal.
>>
>> Anyone know why the /dev/gpt/label name seems so tempramental,
>> and what might be done to make it behave as I've expected?
>>
>> FWIW here is a gpart list of the first of the raid drives (the
>> other three are essentially the same, but with the label digit
>> incremented):
>>
>> Geom name: ada0
>> modified: false
>> state: OK
>> fwheads: 16
>> fwsectors: 63
>> last: 1953525134
>> first: 34
>> entries: 128
>> scheme: GPT
>> Providers:
>> 1. Name: ada0p1
>>    Mediasize: 1000204851712 (931G)
>>    Sectorsize: 512
>>    Stripesize: 0
>>    Stripeoffset: 17408
>>    Mode: r1w1e1
>>    rawuuid: b06b6337-e511-11e0-9d62-00270e0fb8e9
>>    rawtype: 516e7cba-6ecf-11d6-8ff8-00022d09712b
>>    label: raidz1
>>    length: 1000204851712
>>    offset: 17408
>>    type: freebsd-zfs
>>    index: 1
>>    end: 1953525134
>>    start: 34
>> Consumers:
>> 1. Name: ada0
>>    Mediasize: 1000204886016 (931G)
>>    Sectorsize: 512
>>    Mode: r1w1e2
>>
>> and here's the entire contents of /dev/gpt:
>> altroot backup backup3g bootme bootme2 root
>>
>> (no raidz1, etc.)
>>
>> Cheers,
>>
>
>
> --
>
> --------------------------------------------
> Peter Maloney
> Brockmann Consult
> Max-Planck-Str. 2
> 21502 Geesthacht
> Germany
> Tel: +49 4152 889 300
> Fax: +49 4152 889 333
> E-mail: peter.maloney at brockmann-consult.de
> Internet: http://www.brockmann-consult.de
> --------------------------------------------
>
>
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You can always use: gpart show -l

That should display the label.

-- 
George Kontostanos
Aicom telecoms ltd
http://www.aisecure.net