Posts: 318
Joined: Jan 2008
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What's the general concensus on preclearing a drive? Unbelievable that it takes SOO long. And it seems to put a lot of stress on a drive (which I guess is debatably good, especially if it's new).
For those of you that preclear, do you skip the pre-read and post-read stages to speed things up?
Posts: 166
Joined: Jun 2011
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I run it 2 - 3 times for new drives. It's unlikely, but there is still possibility that the new drive is a defect.. I would rather spend 24 - 32 hr pre clearing to find if it's bad or not than to find out my new hdd is bad later when I have some stuff in there.
It's also a good tool to find out if old hdd's are good enough in my opinion. i have 7 hdd's for my unraid i believe. Except for 1, i think they're at least 1 year or 2 old. I wanted to make sure those drive was good and pre_clear does the job in my opiinon.
Posts: 983
Joined: Apr 2012
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13
I agree,..
It may be a pain,..but if the dog barks, give it a bone. (sorry,..I'm just tired and need sleep)
Posts: 2,227
Joined: Dec 2010
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54
I do it for one time.... it's all good. Be safer then sorry....
Posts: 825
Joined: Oct 2009
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7
Eventually the preclear will be a standard part of Unraid. My understanding is that preclear does what Unraid does when you add a drive except that while preclearing you can use the array. Then when you actually add the drive to the array it completes in a few minutes instead of hours.
Posts: 65
Joined: Jul 2013
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I'm currently transferring data from my old unRAID to a new unRAID build. I do not have parity drive active since all my data is on my original unRAID box (with parity).
While I am transferring files, can I be running a pre-clear on a drive in the new build, as well, through a telnet 'screen' session?
Posts: 625
Joined: Aug 2010
Reputation:
23
I do pre-clear and run them the full routine 2-3 times. I also keep some extra drives available that have been pre-cleared so I can always swap out others that may be going bad.
Posts: 65
Joined: Jul 2013
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Is pre-clear a separate process in unRAID and can run concurrently with the transfer of files to other drives in the array?
Posts: 20
Joined: Feb 2014
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I have precleared the parity drive and used in one server for a couple of weeks. No errors whatsoever. Now that I plan to move just the parity disk to a new server and to assign it as a parity disk again, is it necessary to preclear the parity disk again? I guess maybe the new parity calculation in the new server will overwrite previous parity data.
Posts: 19
Joined: May 2011
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The only reason I run pre-clear is to write the file system. I always pick zero pre and post reads. Waste of time IMO.
