Cache disk terminology

[SliMat]

Hi all

 

I have never really bothered with a cache disk and am building a new production machine, so thought I would fit a 500Gb SSD as a cache disk and then mirror this. I plan to run my dockers and VMs on here.

 

Anyway, all the info I can find on setting up a cache disk use the terminology Cache Prefer / Cache Always / Cache Yes / Cache No - which I always found confusing.

 

In the lateset versions this has changed and now in the share options I see Primary Storage Array/Cache and then Secondary Storage Array/Cache... which initially seems far more logical.

 

I want the cache disk to store my appdata/system shares so, I think, I want to set Primary Storage to Cache and then the secondary storage to array (in case the cache disk fills up)... is that right? If so, when I set this, the default mover action is set to Cache -> Array... which, to me, implies that it will by default try and move anything on the cache disk to the array... which I dont think is what I need in this instance.

 

So, am I better off setting secondary storage to None, so that as long as there is space on the cache disk everything will be fine?

 

Is there a revised Tut anywhere which someone can point me to so I can configure this the correct way?

 

I do plan to add a second 500Gb SSD as a mirror before I install this machine, so imagine I just add this as a pool device and then expect there to be a mirror option?

 

Any advice greatly received.

 

Thanks

[Kilrah]

16 minutes ago, SliMat said:

So, am I better off setting secondary storage to None, so that as long as there is space on the cache disk everything will be fine?

Either that or change mover action to Array->Cache, then it'd allow overflow.

 

 

  

16 minutes ago, SliMat said:

I do plan to add a second 500Gb SSD as a mirror before I install this machine, so imagine I just add this as a pool device and then expect there to be a mirror option?

Mirror is the default setting for a pool with 2 slots.

 

Edited November 14, 2023 by Kilrah

[SliMat]

6 minutes ago, Kilrah said:

Either that or change mover action to Array->Cache, then it'd allow overflow.

Thanks - that seemed the logical setting, but I just wanted to make sure as previously the settings haven't been intuitive. I guess the default setting is cache->array for normal shares that use the cache.

Edited November 14, 2023 by SliMat

[itimpi]

1 hour ago, SliMat said:

So, am I better off setting secondary storage to None, so that as long as there is space on the cache disk everything will be fine?

This is the best solution as it allows one to set the share up to be Exclusive which gives best performance as long as you activate the option to have Exclusive Shares under Settings->Global Share Settings.   Otherwise set the mover direction to be array->cache

 

Have you read the section of the online manual here that covers User Shares and the new terminology?   If so, any suggestions for changes that would have made things clearer to you.

 

[SliMat]

7 minutes ago, itimpi said:

Have you read the section of the online manual here that covers User Shares and the new terminology?   If so, any suggestions for changes that would have made things clearer to you.

 

Thanks @itimpi - I was looking for a new Tut to cover the new terminology and didn't find this as there is so much information pertaining to the old terminology. I will change mine to Primary Storage - Cache and Secondary Storage none as I want the performance. Also I will enable Exclusive Shares as this is not something I have seen before.  I will also have a read of the above information and if there is anything I think could be clearer I will let you know. Many thanks

Edited November 14, 2023 by SliMat