I have set up my unraid server, and I'm ready to start the array with 1 parity and 1 data drives, each worth 4 TB. I'm interested in checking both the drives for infant mortality. What's the recommended method to do this with Unraid v6.6? I've read about the preclear plugin, and how it might not be supported with latest versions of Unraid? Or does Unraid do the preclear steps to the parity/data drives (read, write, read cycle for e.g.,) by default?

 

If someone can point me to the current recommended way(s) of checking the drives before I start the array, that would be helpful. Thanks in advance.

As far as I know preclear plugin has been fixed. I haven't used it.

 

Unraid will only clear (write all zeros to it but nothing else is done) a disk when you add it to a new data slot in an array that already has valid parity, so parity will remain valid.

 

@trurl, thanks for your reply. I've kicked off the preclear plugin on both the parity and the data drives now. Just to confirm, after the preclear plugin finishes, when I start the array, should I check the "parity is already valid" box  (because both drives are already 0'd out) or should I go with the Unraid defaults? My understanding is that the preclear plugin writes some sort of a "signature" to the disk, which is used by Unraid subsequently, so I'm hoping I don't have to do anything special....

You should go with defaults as that is safest.    UnRAID will recognise that a pre-cleared disk will not affect parity so will not normally rebuild parity unnecessarily.    Having said that having just 1 data drive and 1 parity drive which are both per-cleared is probably a special case where you get away with selecting the :Parity is already Valid’ option.

1 minute ago, sibi78 said:

@trurl, thanks for your reply. I've kicked off the preclear plugin on both the parity and the data drives now. Just to confirm, after the preclear plugin finishes, when I start the array, should I check the "parity is already valid" box  (because both drives are already 0'd out) or should I go with the Unraid defaults? My understanding is that the preclear plugin writes some sort of a "signature" to the disk, which is used by Unraid subsequently, so I'm hoping I don't have to do anything special....

I don't think you should get to a point where you have a parity valid box to check. That only happens when you do a New Config, which isn't necessary to add a disk to a new data slot. 

 

Even if you were planning to use it as a replacement for a disk already in the array you wouldn't New Config.

 

What are your plans for the disk?

OK, forgot you were starting from scratch with a new array. I'm still not sure you will get a parity valid box though without going through New Config. Just let it sync parity.

Ok, thanks for the suggestions! 

 

I'm planning to copy over ~1 TB of data to the new data drive as opposed to moving an existing drive to the array. I'll probably use the unassigned drives plugin (or network copy - not sure how fast this would be) to do this. As per the thread below, I'm wondering if I should disable parity while copying the files over? Should I merely copy the data to the data drive *before* I start the array, and then assign the parity drive? Or would you recommend starting a new configuration with the parity drive unassigned, and copy over the data to the data drive, and then stop the array, and then assign the parity drive followed by a restart?

 

Thanks again for all your help!

Just wait until after the copy to assign parity