Balancing on initial Writes

[gomer23]

Hello, I have been using DrivePool for a few years for a friend's animation machine. I am setting it up oh a project archive server. What I would like to do if possible is if I am transferring files to the Drive Pool the files balance between the different drives in the pool automatically. For example if I have 3 files I am coping to the pool 1 gets written to each of 3 disks. I will be using SnapRaid with this and don't want any balancing to happen after files are written to their respective disks. So I guess if anything I only want new files to balance between drives. What would be the best setup with the balacing setting to do this.

 

Thanks!

[Christopher (Drashna)]

 

Nothing.  It's the default behavior unless another balancer overrides that behavior. 

 

Also, for the most part, there is no need to disable the balancers.  For the most part, they're designed to NOT move data around much, unless there is a very specific reason that could impact your pool. 

To be blunt, the recommendation or idea that they should be disabled for SnapRAID is a misunderstanding of what they do. 
http://stablebit.com/Support/DrivePool/2.X/Manual?Section=Balancing Plug-ins

• StableBit Scanner: This should only move data off of the drive, it serious issues are detected.  At most, this is the only one you'd want to disable. And even that's arguable.
• Volume Equalization: This only does things if you have multiple partitions/volumes on the same physical disk. This is pretty rare, so most likely, it won't actually do anything. 
• Drive Usage LImiter (previously File Placement Limiter):  This allows you to limit if duplicated or unduplicated data can be placed on a drive.  If left at the defaults, this doesn't actually do anything.  It would only move data around if you uncheck options for drives, and even then.... 
• Prevent Drive Overfill: aka the balancer most likely to move files.  This triggers if any drive is more than 90% full. In that case, it will attempt to move enough data so that it's 80% full.  If the drives get too full, you may end up with "not enough free space" errors on the pool. 
• Duplication Space Optimizer: This balancer's sole purpose is to rebalance data to eliminate the dreaded "Unusable for Duplication" space in a pool.

 

As you may see, most of these can (and probably should) be left on. 

 

 

That said, if you install the SSD Optimizer or Ordered File Placement balancer, these balancers will change this behavior.  

[Christopher (Drashna)]

StableBit DrivePool basically does this by default. 

Unfortunately, it  doesn't do different disks like that.  What it does, is that when each file is created, it checks for the disk with the most available free space, and places the new file on that disk. So, if the disks have equal free space, then it should round robin the disks, like you  want. 

[gomer23]

12 minutes ago, Christopher (Drashna) said:

StableBit DrivePool basically does this by default. 

Unfortunately, it  doesn't do different disks like that.  What it does, is that when each file is created, it checks for the disk with the most available free space, and places the new file on that disk. So, if the disks have equal free space, then it should round robin the disks, like you  want. 

Ah OK that was the behavior I was seeing then. Thank you for the info. So what do I need to disable to keep other balancing from happening but leaving the above behavior?

[gomer23]

Ok perfect thank you. That makes sense with how that is functioning. Thank you for your help!

[Christopher (Drashna)]

You're very welcome!