Can I trust parity or should I rebuilt?


4 posts in this topic Last Reply

Recommended Posts

The only way to have parity valid would be if you clear each and every sector on the drive to zero before it is removed.  Copying files off does not do that, and so the parity will not be valid after the drive removal.

Link to post

The following is copied from another thread that details how to remove a disk without losing parity.   VERY IMPORTANT NOTE:  The command shown will write zeroes to the selected drive (while maintaining parity) ... be CERTAIN you have selected the correct drive.     When the operation completes (it will take a few hours, as it's writing every sector on the drive), that drive will be all zeroes -- which means you can remove it and parity will still be valid.

 

While this is not any quicker than just doing a parity sync, it DOES provide a method to remove drives without impacting parity ... so you can then safely do a New Config without the zeroed drive(s) and check the "Parity is already valid" box.

 

------------------------------------------------------------------------------------------------------------------------------------------------------

 

If you really want to remove a drive and leave parity undisturbed, this will work:

1. Start array in Maintenance mode.  This ensures no file systems are mounted.

2. Identify which disk you're removing, let's say it's disk3.  Take a screen shot.

3. From the command line type:

 

dd bs=1M if=/dev/zero of=/dev/md3   <-- 'md3' here corresponds to 'disk3'
Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.