[OpenIndiana-discuss] Destroying a zombie pool

[Reginald Beardsley]

sigh...

I'm just waking up.  256kb = 512 512b sectors.

It wouldn't do any harm, but I *do* try to be accurate.

--------------------------------------------
On Tue, 4/1/14, Reginald Beardsley <pulaskite at yahoo.com> wrote:

 Subject: Re: [OpenIndiana-discuss] Destroying a zombie pool
 To: "Discussion list for OpenIndiana" <openindiana-discuss at openindiana.org>
 Date: Tuesday, April 1, 2014, 8:45 AM
 
  It's actually quite safe as long as
 the target device is correct.  Cutting and pasting with
 the mouse from the output of "zfs import"
 recommended.   There are potentially two
 labels of 256 kb at the start of the slice and two at the
 end.  I use dd to clear old labels and other stuff off
 disks  all the time.  I also  used it to
 clone OS installs back in  SunOS 4.x times.
 
 For a small slice just do the whole thing:
 
 dd if=/dev/zero of=/dev/rdsk/c?d?s? bs=512
 
 NB: I was a bit numb at the time and actually specified
 bs=4096.  No harm done.  I'd just gotten a bit 4kb
 sector fixated.
 
 
 for big slices two operations are quicker:
 
 dd if=/dev/zero of=/dev/rdsk/c?d?s? bs=512 count=2048
 
 dd if=/dev/zero of=/dev/rdsk/c?d?s? bs=512 skip=NNNN
 
 where NNNN = number of sectors in  slice minus
 2048.   Do the whole slice if you're not
 going to overwrite it and are concerned about data leakage.
 
 On 4kb sector disks, the bs, skip and count values will need
 to be adjusted appropriately.
 
 dd is actually very well behaved, but  user's 
 have been known to be inattentive ;-)
 
 Here's where I found the ZFS info:
 
 https://maczfs.googlecode.com/files/ZFSOnDiskFormat.pdf‎
 
 FWIW I rebuilt my Solaris 10 system from a 2 disk  900
 GB  root pool mirror to a 3 disk 100 GB root pool
 mirror w/ a 1.6 TB RAIDZ1 pool for /export.  A bootable
 RAIDZ disk set.  I plan to repeat the process for an OI
 install and write it up for the wiki.  I just wish we
 had EFI boot so one could use disks over 2 TB this way.
 
 Have Fun!
 Reg
 
 
 --------------------------------------------
 On Tue, 4/1/14, Stefan Müller-Wilken <stefan.mueller-wilken at acando.de>
 wrote:
 
  Subject: Re: [OpenIndiana-discuss] Destroying a zombie
 pool
  To: "Discussion list for OpenIndiana" <openindiana-discuss at openindiana.org>
  Date: Tuesday, April 1, 2014, 2:51 AM
  
  Hi Reg,
  
  as this matter does not really accept failure: could you
  share the whole 'dd' command line? Experimenting on raw
  devices with dd can ruin your day too easily... ;-)
  
  Cheers
   Stefan
  
 
 _______________________________________________
 OpenIndiana-discuss mailing list
 OpenIndiana-discuss at openindiana.org
 http://openindiana.org/mailman/listinfo/openindiana-discuss