I have noticed that when the parity check reaches 3TB the data drives are not read but the 4TB drive parity keeps being checked.

 

To save time can I cancel the parity check at this point?

If you do the parity will not be recorded as being correct.  Despite only a single drive being read at this point the system is still checking that what it is reading is what is expected.

But there is no data to check from 3tb to 4tb as the data drives are only 3tb.

Yes there is.  It will be zero and unRAID is checking to see that it is still zero.

Yes there is.  It will be zero and unRAID is checking to see that it is still zero.

 

That is absolutely correct.

I have noticed that when the parity check reaches 3TB the data drives are not read but the 4TB drive parity keeps being checked.

 

To save time can I cancel the parity check at this point?

 

What "time" are you saving?

 

3 - 4 hours due to upgrading my 5k3000 drives to 7k3000 drives.

3 - 4 hours due to upgrading my 5k3000 drives to 7k3000 drives.

 

So you are saying that once you hit the 3TB mark, it takes another 3-4 hrs to complete?

How much total time does it take you?

 

If all you have are 3TB and under data drives and want to "cut down" the time from the 3-4TB mark, then simplest means would be to replace your 4TB Parity drive with a 3TB drive and rebuild parity. Then you won't have to worry about parity checks going past 3TB.

 

 

It takes about 8 hours to rebuild data from the 5k3000 drives to 7k3000 drives and then about 12 hours to do a parity check.

 

I put in the 4tb parity drive last year to "future proof" my server but I never bothered with 4tb data drives as they are too expensive. I got a good deal on brand new 3tb enterprise Hitachi drives so I decided to change out the "slower" and less warranty 5k3000 hitachi drives.

It takes about 8 hours to rebuild data from the 5k3000 drives to 7k3000 drives and then about 12 hours to do a parity check.

 

I put in the 4tb parity drive last year to "future proof" my server but I never bothered with 4tb data drives as they are too expensive. I got a good deal on brand new 3tb enterprise Hitachi drives so I decided to change out the "slower" and less warranty 5k3000 hitachi drives.

So put one of your new 3TB in as parity until you start adding 4TB data drives.

To save time can I cancel the parity check at this point?

 

Yes, you can cancel it.    But you should, at least occasionally, allow it to complete, as it DOES keep checking that parity is as it should be ... i.e. at this point all it's doing is confirming that the parity drive is all zeroes.

 

 

If you do the parity will not be recorded as being correct.

 

Not correct.    It will in fact record that the parity check was done at the time it was cancelled, and will show the correct number of sync errors that were corrected.    The LOG will show the cancellation; but the status info will be recorded as if the check had run to completion.

 

I will let it complete in full this time round but for the other three times I need to do it I will cancel it at 3tb.

...  for the other three times I need to do it ...

 

What do you mean by this?  You never HAVE to do a parity check.  It's a good idea to check it occasionally [many do it once/month;  some do it once/quarter;  a few never do it; etc. ]    You certainly don't have to do it 4 times at once 

 

 

The answer to your question is further up in this thread.

 

I am upgrading drives.

The answer to your question is further up in this thread.

 

I am upgrading drives.

 

It takes about 8 hours to rebuild data from the 5k3000 drives to 7k3000 drives and then about 12 hours to do a parity check.

 

I had overlooked this line => agree, it's a good idea to do the parity check after each rebuild to confirm all's well before you switch another drive.    Since you've clearly done at least one full parity check already, I'd simply cancel the check after it passes the 3TB mark for each of the additional checks.

 

I have upgraded all drives to the enterprise versions and I have decreased parity checks from 12 to 10 hours (full 4tb check) and rebuild from 9 to 7.5 hours.

 

I stop parity checks as 3tb now, therefore is there any point in getting a 3tb enterprise parity drive?

I stop parity checks as 3tb now, therefore is there any point in getting a 3tb enterprise parity drive?

 

Not really -- it doesn't hurt anything to have the 4GB parity drive; and it does give you the option of adding 4TB drives in the future, should you need more space.

 

You should -- as I've noted before -- at least occasionally let the parity check fully complete, just to confirm that the 4TB drive is still okay between 3 & 4 TB (although in reality, that really wouldn't matter if you were doing a rebuild or data reconstruction while "at risk").    For the majority of parity checks, however, it certainly doesn't hurt to just stop them after they've passed the 3TB point.