Hi - I have recently installed unraid and have a 1tb ssd the i use as a cached drive. i manually start the cache copy and it starts of fairly quickly. when it a fair way into the copy it started getting really slow - the only way i have found to speed it up is restart the machine - then it does a parity check and goes fast again. what could this be ?

Attach Diagnostics to your NEXT post in this thread. 

Thanks - i fixed it by slowing the copy from the mac end using syncopy - limited it to copying only two file at once instead of 4. sadly the Time Machine backup dosent have this option 

 

On 1/7/2025 at 5:30 PM, loobyloo said:

restart the machine - then it does a parity check

It should not do a parity check when you restart unless you didn't shut it down cleanly.

 

And parity has nothing to do with cache. Sort of the whole point of cache is that parity is not involved. No reason parity check would speed anything up.

 

If you are copying to a cached share, then perhaps the reason for the slowdown is because you have filled cache and so it begins to write to the slower array. This is known as overflow.

 

Sounds like you may have some fundamental misunderstandings about Unraid.

 

If you want further advice

On 1/7/2025 at 7:02 PM, trurl said:

Attach Diagnostics to your NEXT post in this thread. 

 

Thanks - will attach next time - the cache wasn't full it still had 200GB. but will attach logs next time it happens