How to use SSD as Cache with File Placement Rules?

[Ozymandias_EBON]

For years I have had 6 drives running great: OS, 4 Pool drives, and a Parity drive for SnapRaid.

The 4 Pool drives are in the same Drivepool, but are used for split purposes: 2 small drives for important data using SnapRaid, 2 large drives for the storage of backup files.

I use File Placement rules to manage where everything goes.

I use the following Balancer plugins (in order): StableBit Scanner, Volume Equalization, Drive Usage Limiter, Prevent Drive Overfill, and Duplicate Space Optimizer.  I have NOT used the All In One Balancer.

Everything has been working great but write performance has been sluggish due to physical drive speed.

 

Today, I wanted to add an SSD drive as a Cache drive (to improve write speed) but it appears that is not possible with how I use the "split" pool.

I added the drive, turned on All In One, disabled all the other Balancers (except for Scanner), and set the Cache drive as an SSD.

I ran a test with a file that should have gone to one of the "important data" drives but it never made it there... it was pushed from the SSD to one of the larger "backup" drives.

I have tried multiple settings but it appears that:

• If I have both "File placement rules respect..." and "Balancing plugins respect..." checked, then Cache is used, All In One ignores File Placement rules, and important files can end up on the Backup drives
• If I uncheck "File placement rules respect...", and check "Balancing plugins respect..." then Cache is ignored
• If I check "File placement rules respect...", and uncheck "Balancing plugins respect..." then File Placement is ignored

I'm sure there is some sort of settings combo that will do what I want but I haven't found it yet.

Any suggestions?

 

[Shane]

Perhaps try the SSD Optimizer instead of the All In One balancer?

You may also need to investigate the effect of ticking/unticking the "Unless the drive is being emptied" option in the Balancing Settings; I vaguely recall that may interact with SSD caching (when the SSD disks are flushed to the Archive disks)?

 

[Ozymandias_EBON]

I didn't have SSD Optimize listed as an available Balancer.

I downloaded the latest version and installed... and now I do.

The odd part is I always use the in-program update check and it always said I was using the latest version.

 

Let me play with SSD Optimize and see what I can do.

Thank you!

[Ozymandias_EBON]

I did some testing and having similar issues with SSD Optimize.

• If I have both "File placement rules respect..." and "Balancing plugins respect..." checked, then Cache is used, SSD Optimize ignores File Placement rules, and important files can end up on the Backup drives (or stay on the SSD drive)
• If I uncheck "File placement rules respect...", and check "Balancing plugins respect..." then Cache is ignored
• If I check "File placement rules respect...", and uncheck "Balancing plugins respect..." then File Placement is ignored

I tried checking and unchecking "Unless drive is being emptied" and no change.

 

I saw an option in previous posts about having a heirarchical pool...

The Main pool (without the SSD) being added to another pool with the SSD, and using SSD Optimize with the new pool. 

This makes sense to me but when I add my Main pool to a new pool, no files or folders from the Main pool are shown...

I only see "System Volume Information" which, I believe, is the only folder on the SSD.

Am I missing a step?

 

PS - One thing that may (or may not) be important. 

My indvidual drives don't have drive letters... I use Mount Points.

 

[Ozymandias_EBON]

I think I found the answer to my issue here:

 

I'll try this out and see how it works.