Do the size of your designated cache drives limit the file size you can add to the pool?

[TAdams]

Hello,

Does the size of your cache drives (I have SSD's set as cache - largest is 1TB) limit the file size that you can add to a pool? I have tried 3 times now to transfer a 1.01TB file to my pool and it has failed at vatying percentages to complete the process. This last time I waited for the SSD to clear and started it as well as bumped up the fill the drive to X% option. Is there a mechanism for bypassing the cache when the file is larger than the cache size is? or perhaps an option somewhere I may very well be missing?

Regards,
Tom

 

[Christopher (Drashna)]

It could, yes, as that data has to be writing to the cache (and therefore the cache drive).  

 

However, it may be worth changing the IO Performance settings for the drive in question, as that may worsen the issue.  Specifically, disable the upload threshold. 

[TAdams]

Christpher,

 First of all, I thought I had already posted this, so it is late! Thank you for your reply, I had an older 2TB WD Black that I designated as a Cache drive which allowed me to transfer the file. I had previously attempted to increase the SSD Optimizer Options "Fill SSD Drives Up to" (set to max) which did not work. This would be rare and I have set an automatic split to prevent these large files in my automated backup settings for the future. Perhaps it would be good option to have an option to bypass placing files on the SSD if file exceeds drive size? I was about ready to pull the trigger on 2 new 250 GB SSD's for temp transfer but am now thinking that may be to low a capacity (obviously depending on file sizes and future file transfers). This would give me, when I have completed adding all drives to pool, 2 X 250GB SSD Cache drives and a single 1 TB SSD Cache Drive not counting the OS SSD.

 

Regards,
Tom

 

 

[Umfriend]

I'm going out on a limb here but I assume that you would not often transfer files of such sizes. If it is rare indeed then you migth consider saving them directly to a PoolPart folder on the HDD of choice and let DP then handle re-allocation / balancing / duplication? Might save a few bucks on large cache SSDs.

[Christopher (Drashna)]

Or create a folder on the drive, and use the File Placement Rules to prevent the contents of that folder from being placed on the SSDs.