Hi,

 

I have just got a new 4TB WD Red

 

I am swapping this to be my cache drive.

 

When i go to preclear it,

 

I get a line that says that the drive does not have a partition table.

 

I took the drive out and attached it to my other pc, made it GPT

 

I then go to preclear and i get "Partition 1 does not start on physical sector boundary."

 

is this ok?

 

Did I need to worry about creating a partition table?

I am reasonably certain that pre-clear wipes any existing partition table, and then creates the partition for unRAID during the pre-clear process.  Therefore is unnecessary to create a partition before running pre-clear.

It's all good, as long as there is no HPA.

Preclear can't wipe that afaik.

 

It doesn't matter whether there is any partition or not before clearing.

 

After clearing, unRAID will prepare the disk as needed depending on how you assign the drive.  Note that parity drives do not have a filing system or partition on them, they are just raw parity data for the other drives in the system.

This is to be a 'cache' drive not parity. Needs to be precleared before use (i'd give a cache drive the full 3 cycles as once in use its not protected by parity as are the other data drives) and then introduced to the array. Once in the array, assign it as cache and an option to 'Format' will be presented. As you've precleared already (well done you!) this takes seconds. Away you go ...

This is to be a 'cache' drive not parity. Needs to be precleared before use (i'd give a cache drive the full 3 cycles as once in use its not protected by parity as are the other data drives) and then introduced to the array. Once in the array, assign it as cache and an option to 'Format' will be presented. As you've precleared already (well done you!) this takes seconds. Away you go ...

A cache drive does not NEED to be pre-cleared (although it is not a bad idea) as it is not part of the parity protected part of the array.

Agreed ... was more  trying to get your second point across. That the cache drive contents are NOT protected by parity which means that your drive really needs to be in good order.

And it would still be ok if I use the drive as Parity? (which I am having to do now)

 

 

And it would still be ok if I use the drive as Parity? (which I am having to do now)

 

I dont understand your question ... bit more detail please.

Ok, I will put it another way...

 

I now am going to use the drive as a parity drive.

 

Having no partition, is not a problem for any drive as pre_clear will do everything it needs.

 

And "Partition 1 does not start on physical sector boundary" does not matter?

It doesn't matter whether there is any partition or not before clearing.

 

After clearing, unRAID will prepare the disk as needed depending on how you assign the drive.  Note that parity drives do not have a filing system or partition on them, they are just raw parity data for the other drives in the system.

 

Seems to answer your question.

If you assigned the drive as parity, it makes NO difference what the partition structure is, as it's all going to be wiped out with the parity data.

 

You also don't "need" to pre-clear it ... except, as already noted, to give the drive a thorough test to confirm it's okay ==> the pre-clear won't save any time at all when you assign the drive as a parity drive -- UnRAID will still have to do a parity sync on it (which will take several hours).