Using an array of M.2 to cache for HDD array causes M.2s to fill continuously

[PhattMatt]

Hello,

I recently purchased 3 Samsung 990 Evo Plus 4TB M.2s to server as a cache for my 109TB HDD single parity array. I setup the HDD array in Windows storage spaces as a single parity array and the Evos in a simple array no resiliency. The problem I have run into is that the drives continue to fill until they hit capacity. Even when the deferred write blocks goes back down to 0 the drives capacity does not reduce and will keep climbing as data is written to them. I have the L2 storage set to %100 write space. Any help would be appreciated.

[tverweij]

I think you have to use the "Free Cache on Written" option in the Advanced defer write options.

[PhattMatt]

I think you have to use the "Free Cache on Written" option in the Advanced defer write options.

I have tired this setup with that option checked as well as unchecked, with the same results.

[Support]

There seems to be a problem on imgur.com and we can't see your image. Can you upload the image to the forum and then change the image link, or use another image hosting site? Thanks.

[PhattMatt]

There seems to be a problem on imgur.com and we can't see your image. Can you upload the image to the forum and then change the image link, or use another image hosting site? Thanks.

I have added it as an attachment as well

[Support]

Thanks, but can you upload a screenshot of the PrimoCache main dialog as the following link describes? We want to see the full statistics.
https://kb.romexsoftware.com/en-us/2-pr ... leshooting

[PhattMatt]

Thanks, but can you upload a screenshot of the PrimoCache main dialog as the following link describes? We want to see the full statistics.
https://kb.romexsoftware.com/en-us/2-pr ... leshooting

[Support]

I see the "Total Write (Req)" is about 8TB, and currently L2 Cache still has 8.79TB space untouched. I don't see anything wrong here. If you mean L2 cache space is not freed after flushed, you may check the following link.
https://kb.romexsoftware.com/en-us/2-pr ... g-released

[PhattMatt]

I see the "Total Write (Req)" is about 8TB, and currently L2 Cache still has 8.79TB space untouched. I don't see anything wrong here. If you mean L2 cache space is not freed after flushed, you may check the following link.
https://kb.romexsoftware.com/en-us/2-pr ... g-released

That’s the problem, the program is showing that the drives space should be available but if you were to look at it in storage spaces it would be %100 filled. When the logical volume hits %100 filled in storage spaces it takes the storage space offline automatically. Once the logical volume goes offline primocahce stops working because the volume used for the cache is no longer online. That’s what I mean by it fills continually.

[Nick7]

For one, why setup array in storage spaces, and use that for cache?
You should use disks themselves, without SS for caching.

2nd - you are confusing some things. Freeing cache on written is freeing cache within L2 cache in Primocache.
This will *NOT* free up space in underlying caching device! Especially in thin provisioned SS drive!

Again, please use SSD's for caching without SS!