How to replace my cache drive

[xtrips]

I would like to replace my SSD cache drive with a bigger SSD drive.

I thought about launching the mover first.

Than shutdown and clone my cache drive to the new one.

And finally put the new one back in place.

 

Is that ok?

Any suggestions?

 

 

Sent from my iPad using Tapatalk Pro

[JonathanM]

If you shut down docker and VM services, so the tabs don't appear in the main GUI, you can set all shares to cache yes, run the mover, and the cache drive SHOULD be totally empty, so no need to clone.

[xtrips]

If you shut down docker and VM services, so the tabs don't appear in the main GUI, you can set all shares to cache yes, run the mover, and the cache drive SHOULD be totally empty, so no need to clone.

I didn’t get the “set all shares to cache yes”.
What does that do? How does it not write to cache then?


Sent from my iPad using Tapatalk Pro

[itimpi]

8 minutes ago, xtrips said:

I didn’t get the “set all shares to cache yes”.
What does that do? How does it not write to cache then?


Sent from my iPad using Tapatalk Pro

Shares need to be set to cache Yes to get mover to move files from cache to array (this is described in the GUI built-in Help).

Edited June 24, 2019 by itimpi

[xtrips]

Shares need to be set to cache Yes to get mover to move files from cache to share (this is described in the GUI built-in Help).

Ahhh ok
Thanks


Sent from my iPad using Tapatalk Pro

[xtrips]

Did you mean this?
After I stopped the Docker service, and launched the mover, there still the appdata folder and the .docker.img file on my cache drive.
Did I miss something?

[JonathanM]

First, do you still see the word "Docker" in the web GUI?

Second, when you click on the word "Shares" in the web GUI, and then click on each individual share listed there, are they all set to cache: yes?

[xtrips]

6 minutes ago, jonathanm said:

First, do you still see the word "Docker" in the web GUI?

Second, when you click on the word "Shares" in the web GUI, and then click on each individual share listed there, are they all set to cache: yes?

No, the Docker icon has disappeared.

The appdata was set to cache "prefer".
I now et it to yes.
Is that what you meant?

 

Update: the appdata moved,

What remains is a 20 Gb .docker.img file

Edited June 24, 2019 by xtrips

[JonathanM]

Just now, xtrips said:

No, the Docker icon has disappeared.

The appdata was set to cache "prefer".
I now et it to yes.
Is that what you meant?

Yep, Mover should now clean appdata off the cache drive and put it on the array. Are there any other folders on the cache drive?

[xtrips]

Just now, jonathanm said:

Yep, Mover should now clean appdata off the cache drive and put it on the array. Are there any other folders on the cache drive?

Just an empty backup folder and the 20 Gb .docker.img file.
I could relaunch the dockers and set the image file to be on the media.
Is that a good thing to do?

[JonathanM]

2 minutes ago, xtrips said:

Just an empty backup folder and the 20 Gb .docker.img file.
I could relaunch the dockers and set the image file to be on the media.
Is that a good thing to do?

So the docker img file is in the root of the cache drive, not inside a folder?

[xtrips]

Just now, jonathanm said:

So the docker img file is in the root of the cache drive, not inside a folder?

Exactly.
The Docker vDisk Location is     /mnt/cache/.docker.img
Should I set it at /mnt/user/ ..... ?

[JonathanM]

1 minute ago, xtrips said:

Exactly.
The Docker vDisk Location is     /mnt/cache/.docker.img
Should I set it at /mnt/user/ ..... ?

Do you have a "system" share?

[xtrips]

I think I set it there. I thought it would be wise, more reliable or accessible, or faster for the dockers to load from there. I guess I was wrong since it loads in memory anyway.

And no, no system share. 

[xtrips]

I could simply copy the dockers.img file to media and after I make the swap put it back on cache. And only after launch back the dockers. No?

[xtrips]

This is what the help file says:

 

You must specify an image file for Docker. The system will automatically create this file when the Docker service is first started.

It is recommended to create this image file outside the array, e.g. on the Cache pool. For best performance SSD devices are preferred.

 

The dockers service is stopped. How does the file remains visible then?

[JonathanM]

Just now, xtrips said:

I could simply copy the dockers.img file to media and after I make the swap put it back on cache. And only after launch back the dockers. No?

You could, but that's not ideal. Here is what I recommend.

1. Run mover, verify only things left on the old cache drive is the docker image and empty folders, no real data.

2. Stop array, unassign cache device, shut down, physically swap cache drive, power back up.

3. Assign new cache device to slot, start array, format new cache drive, set appdata share back to cache prefer, run mover.

 

Now, you have a choice to make.

Allow unraid to create the docker image file as it was, on the cache drive root. That choice will happen automatically when you enable the docker service if you make no changes.

Or, create a new cache prefer share that will hold your docker image file, and set the image file location to that new share. I think the defaults are to have a share called system, so the docker image would be /mnt/user/system/docker.img

 

Either way, after you enable the docker service, go to the apps tab and click on previous apps under menu on the left, and select all the apps you want to put back.

[JonathanM]

4 minutes ago, xtrips said:

The dockers service is stopped. How does the file remains visible then?

The docker image file is persistent, it keeps a local copy of all the common elements of the dockers you use so they don't have to be redownloaded at every boot. Recreating it is simple, and a normal part of upkeep if something goes wonky with your dockers.

[JorgeB]

If current cache is btrfs you can do an online replacement, and can even continue to use it normally during it.

[xtrips]

Hello.

The cache disk swap went well.

Importing the .dockers.img file in the end raised alerts that it might be unstable and the recommendation was to build it anew, which I did.
Surprisingly reinstalling my apps found the old config and everything returned back to where it was.
The only hiccup was and still is the appdata folder.
Remember I had to change the setting from prefer to yes, and that moved the appdata from the cache disk somewhere else (?).
Now after everything is restored I get this warning:
 

WARNINGS FOUND SUGGESTED FIX

Share appdata set to cache-only, but files / folders exist on the array You should change the share's settings appropriately  or use the dolphin / krusader docker applications to move the offending files accordingly. Note that there are some valid use cases for a set up like this. In particular: THIS

 

Move it from where? I set it to prefer again but the warning stays.
I don't see it in the array. 

[JonathanM]

It sounds like you skipped the last part of this step, or moved on and tried to complete it out of order.

18 hours ago, jonathanm said:

3. Assign new cache device to slot, start array, format new cache drive, set appdata share back to cache prefer, run mover.

Since you started docker before you completed this step properly, you now have duplicate files on one of your array disks and the cache disk. The mover won't be able to resolve duplicates, you will have to do it manually.

 

Disable the docker service again, and use mc at the console or ssh command line to move the appdata folder from /mnt/disk1 or whichever disk number it's currently on to /mnt/cache. You will get warnings that the files exist, do you want to overwrite, yes to all.

[xtrips]

Hello. I replaced my cache drive and added a faster SATA controller which brought it to 6Gb/s speed.
I was wondering, I have a second SATA port available on the controller, will I gain anything by porting my Parity drive to that higher speed port?

[itimpi]

1 hour ago, xtrips said:

Hello. I replaced my cache drive and added a faster SATA controller which brought it to 6Gb/s speed.
I was wondering, I have a second SATA port available on the controller, will I gain anything by porting my Parity drive to that higher speed port?

Unlikely as HDD type drives cannot exploit the extra speed.

[mbc0]

On 6/25/2019 at 7:22 AM, johnnie.black said:

If current cache is btrfs you can do an online replacement, and can even continue to use it normally during it.

Hi I know this is old but can you please advise the steps for carrying out an online replacement please?

 

Thank you

[John_M]

26 minutes ago, mbc0 said:

Hi I know this is old but can you please advise the steps for carrying out an online replacement please?

 

Thank you

 

From the FAQ: