how to fix "CORRUPT" partition table in mirrored drive

[William Dudley]

Warren,

Again, thanks for the reply.  Does the fact that gpart show -l reports this:

=>        63  3907029104  mirror/gm0  MBR  (1.8T) [CORRUPT]

Mean that I'm screwed and must copy all the data to a new drive and
create the mirror anew?

Can I remove the second drive from the mirror and still have the data on it
accessible?
the gmirror man page doesn't say what the disks that are removed from the
mirror "look like",
i.e. are they in some wierd format or can they be read like a normal disk.

Thanks,
Bill Dudley


This email is free of malware because I run Linux.

On Thu, Jun 25, 2015 at 7:57 PM, Warren Block <wblock at wonkity.com> wrote:

> On Thu, 25 Jun 2015, William Dudley wrote:
>
>  I have a mirrored drive:
>>
>> gpart show -l
>> =>      63  78156225  ad0  MBR  (37G)
>>        63  78156162    1  (null)  [active]  (37G)
>>  78156225        63       - free -  (31k)
>>
>> =>       0  78156162  ad0s1  BSD  (37G)
>>         0  41943040      1  (null)  (20G)
>>  41943040   2097152      2  (null)  (1.0G)
>>  44040192  34115970      4  (null)  (16G)
>>
>> =>        63  3907029104  mirror/gm0  MBR  (1.8T) [CORRUPT]
>>          63  3907029105           1  (null)  [active]  (1.8T)
>>
>> =>         0  3907029105  mirror/gm0s1  BSD  (1.8T)
>>           0   335544320             4  (null)  (160G)
>>   335544320   209715200             5  (null)  (100G)
>>   545259520   209715200             6  (null)  (100G)
>>   754974720  3152054385             7  (null)  (1.5T)
>>
>> I tried to fix the corrupt partition table like this:
>>
>> gpart recover mirror/gm0
>> gpart: recovering 'mirror/gm0' failed: Function not implemented
>>
>> So how do I fix the corrupt partition table?  Can I un-mirror the two
>> drives
>> and then do the gpart recover and then re-mirror them?
>>
>
> gpart recover only works with some partitioning schemes.  GPT has a backup
> copy of the partition table that can be used to recover the primary one.
> MBR and BSD partitioning schemes do not have redundant metadata for recover
> to use.
>