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jacksonliam

Very slow parity copy on parity swap

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I am trying to use the parity swap procedure to upgrade my parity disk from a 2TB WD Green (5400RPM) to a 4TB WD Blue (WD40EZRZ, 5400RPM, CMR). Using the old 2TB drive to replace a data disk with SMART errors.

 

This is on an N54L microserver with the AMD Turion II Neo Dual Core @2.2Ghz. Unraid was just upgraded to 6.8.3 from 6.1 prior to starting the swap.

 

I started the array copy yesterday but it has only done 17% in 26 Hours.  CPU usage bar sitting around 60% with one core sitting near 90%.

 

Is this expected? I know this isn't the fastest hardware, but surely it shouldn't take a week to copy 2TB?

 

Is there any way to do this faster? If it is a CPU issue can I take the drives out and do the copy (e.g. with dd) on my desktop?

 

Thanks in advance!

Edited by jacksonliam

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32 minutes ago, jacksonliam said:

Is this expected?

No

 

Go to Tools - Diagnostics and attach the complete Diagnostics ZIP file to your NEXT post in this thread.

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Nothing obvious there and nothing in syslog really after parity copy begins.

 

43 minutes ago, jacksonliam said:

I know this isn't the fastest hardware

Can you tell us more about the hardware?

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4 minutes ago, trurl said:

Nothing obvious there and nothing in syslog really after parity copy begins.

 

Can you tell us more about the hardware?

Thanks for looking!

 

Not much more to add than its:

N54L HP Microserver

AMD Turion II Neo Dual Core @2.2Ghz

8GB RAM (RAM usage around 13%).

 

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Write cache is disabled for all disks, HP Microservers have a write cache setting in the BIOS that is disabled by default, enable it and try again.

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1 hour ago, johnnie.black said:

Write cache is disabled for all disks, HP Microservers have a write cache setting in the BIOS that is disabled by default, enable it and try again.

Thanks, that appears to have done the trick! Now going at about 1% every 12 minutes (so should complete in 20 hours!)

 

Do you know if there is a risk to the whole array if I leave write cache enabled? Or would it just be a case of the files being written (e.g. currently being moved by mover) becoming corrupted in the event of power failure?

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There's an increased risk of data corruption if there's a power failure, but it would only affect files being copied at the time, also you can (should) get a UPS.

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