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Draven

Parity swap

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Hello everyone,

 

I will try to be as clear as possible. Here's the deal. I want to upgrade my parity drive (from 3TB to 4TB) because I will add a 4TB data drive soon. I would like to put the new parity drive in the same slot  as the old parity drive (SATA1 on my motherboard). Is it possible to copy the old parity drive on the new (precleared) drive, unassigned the old parity drive, shutdown the machine, replace the old parity drive with the new one (SATA1 on my motherboard), start the machine, assign the new parity drive (with the parity data on it!) and start the array?

 

Is this possible? Is this recommended? And if so, how can I copy the parity drive (drive assignments)?

 

Thank you for your time,

Draven

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Possible yes, but not much point since the server would be offline (or online without parity) during the copy, just replace the parity disk and let Unraid resync parity.

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UnRAID does not care where the drive is physically connected as it recognises disks by their serial number so you can move drives between SATA ports at any time without affecting the logical assignment within the Unraid GUI.

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ok, so, to sum it :

 

1- Stop the array

2- Shutdown the server

3-Add the new parity drive on my LSI 9207-8i card

4- Start the server

5- Preclear the drive

6- Stop the array and switch from the old 3TB to the new 4TB in the parity drive assignment

7- Start the array

8- Let unRAID rebuild parity drive on the 4TB

9- Shutdown again to put the drive from the LSI card to the SATA1 on the motherboard, removing the old 3TB

10- Start the server

11- Done?

 

Switching the drive from my LSI Card to the motherboard is not supposed to change the drive assignment in unRAID? My last parity check is about 2 weeks old, is this OK or should I do a parity check just before the swap? Then, after the rebuild, I can preclear the old parity drive (3TB) and add it to the array?

 

Sorry, a lot of questions, but I just want to be 100% sure...

 

Thank you for your time,

Draven

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Pretty much. You just have to remember take a screen shot of your drive layout. Trust me I know its something so simple, but its easy to accidentally assign the wrong drive in the wrong spot. unRAID is pretty good at remembering, but its cheap insurance. 

 

Your plan is pretty much spot on to the order of what you need to do. unRAID doesn't care which ports which drives are connected to. So if its on your LSI card or your Motherboard it simply sees a serial number and an assignment in the unRAID GUI. You could literally unplug all your drives and swap all the cables around. As long as your drive assignments in the GUI are right it will be completely fine. 

 

 

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It is worth pointing out that there is no advantage to pre-clearing a drive to be used as a parity drive (except as a confidence test of the drive) as rebuilding parity writes to every sector on the drive anyway over-writing any existing content.

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