Replacing Cache Disk questions

[wayner]

It looks like my Cache disk is failing (see here) so I am going to replace it.  I am going from these directions (Replacing or upgrading your Cache drive - for unRAID v6.2 and above), are those the correct instructions or are there newer instructions - note that I am currently running unRAID 6.4.1?

 

A few questions:

1. It looks like the process is to move the files from the Cache drive to the array using Mover, then to disable and remove the cache drive, install a new cache drive and then to use Mover to move the files to the new cache drive.  Is there a more direct method where you add a second cache drive, move the files from the first cache drive to the second cache drive, and then to remove the first cache drive?
2. Step 3 in these instructions is "Click on Shares and set all shares present on your Cache disk to Use cache disk: Yes. This will cause the Mover to move all shares OFF the Cache drive!"  Why do you change the Use cache disk to Yes rather than No?  How does changing the setting to Yes to cause the files to move off of the cache drive?
3. My cache drive that is failing is a 240GB SSD.  It is currently over 50% full.  Is there any reason to use a larger cache drive now that larger SSDs are cheaper?
4. Is there anything that I should do now that I have a new drive, like change how much space the dockers can use?  I occasionally get errors that my docker space is getting full .  How do I increase the space that docker uses as I don't see it in Settings-Docker (even under Advanced view - here is what it currently shows):

Label: none  uuid: 97f1537f-8546-4942-ba6b-174c665d70f3
	Total devices 1 FS bytes used 12.26GiB
	devid    1 size 20.00GiB used 17.27GiB path /dev/loop2

Is there anything else I should do while I am at this?

 

Thanks for your help!

[Frank1940]

(1) you are welcome to do anything you want to.  But you have found the instructions of a tested method will will complete the job with a minimum of 'gotcha's' for anyone who will follow the instructions.  While the the instructions are detailed with a number of short steps, many of them will be completed while you are reading the next one.  The only extra time is that required for the copying/(moving with mover) of the files back to the cache drive. 

 

(2) This goes back a number of years when the only use of the cache drive was to temporarily cache files until they could be copied onto the protected array by the mover.  There were two choices at that time-- Yes (to use the cache drive to temporarily store the files) or No (To bypass the use of the cache drive and write the files straight to the protected array).   PS-- You are not the only one who has had this question lately. 

 

(3)  Assuming you have only a single cache drive, you can replace with any drive that will hold all of the data that you need to store on it.  Now, that is a bit a smart-aleck response but I would get whatever is the best-bang-for-the-buck.  Within reason, always get the largest disk you can justify. 

 

(4)  See here:

           

You can find several more posts by Googling with these terms---   unraid increase docker .img size

Edited September 2, 2019 by Frank1940

[JorgeB]

You can do an online replacement, but note the bold comments about single cache pool:

https://forums.unraid.net/topic/46802-faq-for-unraid-v6/?do=findComment&comment=480419

 

[wayner]

Thanks Johnnie - that looks perfect.  I thought I had a spare 240GB SSD but I don't so I have to wait for a new one to come from Amazon.

[wayner]

16 hours ago, Frank1940 said:

(4)  See here:

           

You can find several more posts by Googling with these terms---   unraid increase docker .img size

I found that before but I don't appear to have an option to change the size.  The only setting I have on the Docker Setting page is Enable Docker (Yes/No).  Perhaps I have to stop all of the dockers first, or disable the dockers?