Re: kern/57081: ZFS pool rolled back two years, all data lost since.

[Taylor R Campbell <riastradh%NetBSD.org@localhost>]

The following reply was made to PR kern/57081; it has been noted by GNATS.

From: Taylor R Campbell <riastradh%NetBSD.org@localhost>
To: Roy Marples <roy%marples.name@localhost>
Cc: gnats-bugs%NetBSD.org@localhost
Subject: Re: kern/57081: ZFS pool rolled back two years, all data lost since.
Date: Fri, 11 Nov 2022 10:29:28 +0000

 > Date: Fri, 11 Nov 2022 10:23:19 +0000
 > From: Roy Marples <roy%marples.name@localhost>
 > 
 > On 11/11/2022 10:00, Taylor R Campbell wrote:
 > > 1. Can you make an archive of the vdevs, and any zpool.cache file,
 > >     onto another medium just so that you don't lose anything more in
 > >     the event of experimentation?
 > 
 > Unsure how?
 > I will prep a spare disk to boot from in the meantime.
 
 Just dd from the raw disk onto a spare disk -- in this case, it looks
 like your zpool is just on dk5, so copy the content of dk5 to
 somewhere else.
 
 > > 4. Can you share output from `zdb -e -l <vdev>' and from `zdb -e -h
 > >     <pool>'?
 > 
 > # zdb -e -l /dev/dk0
 > cannot open '/dev/dk0': Device busy
 > # zdb -e -h rpool
 > zdb: can't open 'rpool': No such file or directory
 > # zdb rpool
 > zdb: can't open 'rpool': Device busy
 
 Can you do these from single-user mode, without the zpool imported?
 
 <vdev> here should be `/dev/rdk5', judging by your description.