Question about swapping a parity drive and pre-clearing

[bobalot]

Hi,

 

I have been reading the official tutorial wiki on this and watching some YouTube videos on this.

 

There is a recommendation about pre-clearing the new parity drive. Just want to confirm I'm doing this in the right order.

 

I have the following:

 

1x 8TB parity drive

2x 4TB data drives

1x 8TB data drive

 

All my SATA slots are used up.

 

I have a new 1x 16TB hard drive

 

I want to:

 

• Replace the 8TB parity drive with the 16TB hard drive.
• Replace one of the 4TB hard drives (which is currently basically empty) with the former 8TB parity drive.

 

This is what I plan to do:

 

1. Stop the array
2. un-assign the 4TB hard drive (which I want to replace with the current 8TB parity drive)
3. Start the array and check the "Yes I want to do this"
4. Stop the array
5. Power down
6. Take out the 4TB hard drive
7. Install the 16TB hard drive
8. Power On
9. Stop the array
10. Pre-Clear the the 16TB hard drive <- This is the only difference from the tutorial
11. Un-Assign the current 8TB Parity drive
12. Assign the 16TB drive in the parity slot
13. Assign the former 8TB parity drive into slot for the old 4TB hard drive (which I removed)
14. Go to the Main ->Array Operation
15. Put check in the "Yes, I want to do this" and click copy and then wait a long time
16. Once the start button is available, check "Yes, I want to do this" and click start.

 

Is this the correct way of doing this?

Edited December 20, 2023 by bobalot

[Frank1940]

 

I just did this and this was my procedure:

 

1.  Preclear the new 16TB drive.  (I don't want an 'infant mortality' failure in the subsequent operations! But this is optional depending on your tolerance for problems...) Make note of the last four digits of the 16TB drive.  Make note of the serial number of the present 8TB parity drive.

 

2.  If you haven't done a parity check recently, do one now!  (You don't want to be dealing with a undetected disk problem in the following steps...

 

3.  Shut the server down.  Remove the present Parity Drive. Verify serial number on this drive and set aside.  Install new 16TB drive.  (VERIFY that all SATA DATA and Power connectors are firmly seated!!!!)

 

4.  Power up server.  Unraid will detect that the Parity Drive is missing.  Assign the 16TB as Parity.  (Use the dropdown box...) 

 

5.  Start the array and rebuilt parity.

 

6.  Get the last four digits of serial number of the 4TB data drive you want to replace.  Shut the server down again. Pull that drive and verify its serial number.  Install the old Parity drive in its place.   (VERIFY that all SATA DATA and Power connectors are firmly seated!!!!)   Start up server.  Again, it will detect the missing drive.  Assign the old Parity Drive as its replacement. 

 

7. Start the array and rebuild the that disk.

 

All of this will take a few days, so be prepared.   Notice that you will not be losing any data using this procedure and the server will be available throughout the procedure while it is up.  (But using it will impact its performance and extend the time required to complete each step. So a bit of planning may be required to minimize the impact on users.) 

 

It appears that available storage is not currently a problem as you said you have a 4TB drive that is "basically empty".  So you can do steps 6 & 7 at a later date and still have the server running normally until you have a clear window of time to finish the job with minimal disruption.  Remember that you should now be prepared to always buy 16TB drives from this point on.  (Otherwise, you may find yourself removing a perfectly good drive to gain more storage space.  (I know this as I now find myself in this situation...) 

 

[bobalot]

17 hours ago, Frank1940 said:

 

I just did this and this was my procedure:

 

1.  Preclear the new 16TB drive.  (I don't want an 'infant mortality' failure in the subsequent operations! But this is optional depending on your tolerance for problems...) Make note of the last four digits of the 16TB drive.  Make note of the serial number of the present 8TB parity drive.

 

2.  If you haven't done a parity check recently, do one now!  (You don't want to be dealing with a undetected disk problem in the following steps...

 

3.  Shut the server down.  Remove the present Parity Drive. Verify serial number on this drive and set aside.  Install new 16TB drive.  (VERIFY that all SATA DATA and Power connectors are firmly seated!!!!)

 

4.  Power up server.  Unraid will detect that the Parity Drive is missing.  Assign the 16TB as Parity.  (Use the dropdown box...) 

 

5.  Start the array and rebuilt parity.

 

6.  Get the last four digits of serial number of the 4TB data drive you want to replace.  Shut the server down again. Pull that drive and verify its serial number.  Install the old Parity drive in its place.   (VERIFY that all SATA DATA and Power connectors are firmly seated!!!!)   Start up server.  Again, it will detect the missing drive.  Assign the old Parity Drive as its replacement. 

 

7. Start the array and rebuild the that disk.

 

All of this will take a few days, so be prepared.   Notice that you will not be losing any data using this procedure and the server will be available throughout the procedure while it is up.  (But using it will impact its performance and extend the time required to complete each step. So a bit of planning may be required to minimize the impact on users.) 

 

It appears that available storage is not currently a problem as you said you have a 4TB drive that is "basically empty".  So you can do steps 6 & 7 at a later date and still have the server running normally until you have a clear window of time to finish the job with minimal disruption.  Remember that you should now be prepared to always buy 16TB drives from this point on.  (Otherwise, you may find yourself removing a perfectly good drive to gain more storage space.  (I know this as I now find myself in this situation...) 

 

Thanks!

 

Wondering how to preclear the 16TB drive before starting this process. I have no spare SATA slots.

[foo_fighter]

Just now, bobalot said:

Thanks!

 

Wondering how to preclear the 16TB drive before starting this process. I have no spare SATA slots.

You can pre clear it over usb, with usb 3.0 it'll run just as fast as internally. 

[bobalot]

On 12/21/2023 at 6:00 PM, foo_fighter said:

You can pre clear it over usb, with usb 3.0 it'll run just as fast as internally. 

Thanks.

 

Did exactly that and it worked.

 

The preclear took 60 hours which seemed a bit excessive.

[ConnerVT]

No, for 16TB that's about right.  Perhaps even a bit faster than usual.

 

The UD Preclear runs through the entire disk three times.  It reads the entire drive, then writes zeroes, then reads again.  So right around 3x the time it would take to do a parity check on an array containing these same model drives.

 

I just recently precleared two HGST 16TB drives, mounted with a SATA HBA.  Took just over 63 hours.

Edited December 26, 2023 by ConnerVT