[Lustre-discuss] Recovering a reformatted OST

[Bob Ball]

Thank you, Andreas.  I feel a bit better now.

bob

On 1/30/2015 11:25 AM, Dilger, Andreas wrote:
> On 2015/01/29, 12:34 PM, "Bob Ball" <ball at umich.edu> wrote:
>
>> This is Lustre 2.1.6.
>>
>> I did a dumb thing.  I reformatted a drained OST BEFORE I saved off
>> appropriate data to re-establish it at its old index.  I don't know what
>> I was thinking?  The files that I would normally restore are,
>> LAST_ID
>> last_rcvd
>> mountdata
>> umt3-OST0020
>>
>> I know how to recreate the correct LAST_ID.  And, as this happened over
>> a year ago on this same OST, I have old copies still of each of the
>> others.  I know that "mountdata" is created when I created the lustre
>> file system, so I would guess I can just continue to use that file.
>>
>> My question, can I simply re-use these other, old file copies when I am
>> ready to once again put a Lustre file system on this volume?
> The mountdata file should be the same.  The last_rcvd file will be
> recreated during mount if it is missing, though the old one could also be
> used.  The umt3-OST0020 config file would be recreated with a --writeconf,
> but it may also be created automatically during mount if missing (it is an
> OST-local copy of the MGS file of the same name so the OST can mount even
> if the MGS is offline).
>
> Cheers, Andreas