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KeithLM

Cache drive filling when running mover

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Posted (edited)

My cache has been running hot, I was thinking of swapping it with another drive, or using a different SSD as the main cache, and when I activated the mover it quickly started filling up the cache drive.  I went from having 35GB or thereabouts on the cache to having over 300GB!  This is kind of the opposite of what I wanted to have happen.  It seems to be copying a virtual disk I use as a secondary drive for my virtual machine from disk7 to the cache, and that can't possibly fit on there.  I can't see why it should want to do that.  

 

 

Edited by KeithLM

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2 minutes ago, KeithLM said:

I can't see why it should want to do that.

Neither can we. You somehow forgot to post enough information for us to be able to help.

 

Maybe you have configured cache "prefer" for some share, instead of "yes"?

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I don't recall that option.  I know I specified "yes" and "no" on some, but where did "prefer" come from?  This domains share, something I don't recall creating myself, was set to "prefer". 

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45 minutes ago, KeithLM said:

I don't recall that option.  I know I specified "yes" and "no" on some, but where did "prefer" come from?  This domains share, something I don't recall creating myself, was set to "prefer". 

The setting "prefer" means "please unRAID - move any files from the array and to the cache."

 

Visit the settings for a share and hold the mouse pointer over the "Use cache disk:" label and click, and you will see an explanation of what the different options means.

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1 hour ago, KeithLM said:

I don't recall that option.  I know I specified "yes" and "no" on some, but where did "prefer" come from?  This domains share, something I don't recall creating myself, was set to "prefer". 

The domains share is created for you to help you set up virtual machines. It is cache-prefer by default because most people want the performance provided by cache for their VMs. Similar for the shares created for use by Docker.

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And cache-prefer isn't the same as cache-only. Prefer allows overflow to the array, with moving back to cache when space is available. It also allows people who add cache after their system is configure to have files moved to cache automatically.

 

Here is a more detailed explanation of the different Use cache options:

 

https://lime-technology.com/forums/topic/46802-faq-for-unraid-v6/?page=2#comment-537383

 

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OK, thanks for the info.  For my usage cache isn't needed for the virtual drive, and it'd fill up my cache anyways.  So I changed that setting and it's working as expected now.  I added the virtual drive a year ago and hadn't noticed it consuming all the drive, but some of it was always there.  

 

One of the good things about unRAID is that for the most part I just leave it be and everything is fine and I don't even think about it for months.  One of the bad things about unRAID is that since I go so long without dealing with it I forget about some of the features and settings and how I configured them.  

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4 hours ago, KeithLM said:

For my usage cache isn't needed for the virtual drive, and it'd fill up my cache anyways. 

 

Some of us use cache only for docker / VM performance, and never use cache for writes that are destined for the array. Maybe the way you are using it is fine for you, but caching normal writes to the server isn't required, and if you don't use cache that way, you would have more space for using cache to improve performance of dockers / VMs.

 

4 hours ago, KeithLM said:

for the most part I just leave it be and everything is fine and I don't even think about it for months

 

Make sure you have setup Notifications!!!

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