ZFS Partition GUID all zeros?

[Jeff Rizzo <riz%tastylime.net@localhost>]

I was getting some help with related problems on IRC earlier today (I 
think they're mostly sorted) , and it didn't even think about this one:  
the `gpt` command seems to have created partitions with all-zeros GUID.

Background: I'm replacing some 4TB disks in a ZFS raidz2 with 16T disks 
- I swapped out my second one today.  I just noticed, though, that the 
GUIDs of the partitions (well, some of them) on the new disks are all zeros!

The partitions I created recently (under NetBSD 10) look like this:

cassava:riz  ~/gitsrc> gpt show -a wd0
        start         size  index  contents
            0            1         PMBR (active)
            1            1         Pri GPT header
            2           32         Pri GPT table
           34           30         Unused
           64       524288      3  GPT part - EFI System
                                 Type: efi
                                 TypeID: 
c12a7328-f81f-11d2-ba4b-00a0c93ec93b
                                 GUID: 00000000-0000-0000-0000-000000000000
                                 Size: 256 M
                                 Label: uefiboot1
                                 Attributes: None
       524352    230162368      1  GPT part - NetBSD RAIDFrame component
                                 Type: raid
                                 TypeID: 
49f48daa-b10e-11dc-b99b-0019d1879648
                                 GUID: c209ba9e-8503-4506-8e5c-c30771f60d65
                                 Size: 110 G
                                 Label: bootraid1
                                 Attributes: biosboot
    230686720  31021072351      2  GPT part - ZFS
                                 Type: zfs
                                 TypeID: 
516e7cba-6ecf-11d6-8ff8-00022d09712b
                                 GUID: 00000000-0000-0000-0000-000000000000
                                 Size: 14792 G
                                 Label: zfswd1
                                 Attributes: None
  31251759071           32         Sec GPT table
  31251759103            1         Sec GPT header


... and the older ones (created under NetBSD 9.99.86 or thereabout) look 
like this:


cassava:riz  ~/gitsrc> gpt show -a wd2
       start        size  index  contents
           0           1         PMBR (active)
           1           1         Pri GPT header
           2          32         Pri GPT table
          34          30         Unused
          64      524288      1  GPT part - EFI System
                                 Type: efi
                                 TypeID: 
c12a7328-f81f-11d2-ba4b-00a0c93ec93b
                                 GUID: 6bd04bd1-fe25-4eba-ad4d-8c0cfd711f82
                                 Size: 256 M
                                 Label: uefiboot2
                                 Attributes: None
      524352   230162368      3  GPT part - NetBSD RAIDFrame component
                                 Type: raid
                                 TypeID: 
49f48daa-b10e-11dc-b99b-0019d1879648
                                 GUID: ef4a8149-0c78-4870-bd23-fb73b3961bb1
                                 Size: 110 G
                                 Label: bootraid2
                                 Attributes: biosboot
   230686720  7583350400      2  GPT part - ZFS
                                 Type: zfs
                                 TypeID: 
516e7cba-6ecf-11d6-8ff8-00022d09712b
                                 GUID: ed2b444b-bc95-42ab-9ff2-38580ed56420
                                 Size: 3616 G
                                 Label: zfswd2
                                 Attributes: None
  7814037120          15         Unused
  7814037135          32         Sec GPT table
  7814037167           1         Sec GPT header


So... how bad is it that I have four GPT partitions with the same GUID?  
:)  Can I edit them? And how do we think this happened?

+j



--
Jeff Rizzo
riz%tastylime.net@localhost
+1 415 823 1847