Folder Duplication - Drive Merge feature

Comments

• Alex

  July 2011 edited July 2011 Covecube

  I think you've run into the duplication fail-over code.

  
  

  When writing to a duplicated folder, DrivePool writes to 2 hard disks at the same time so that you don't need a background balancing process to go over and re-duplicated the files.
  

  
  

  But if you want to turn of duplication after the fact, DrivePool needs to go through each file and duplicate it. If a file can't be duplicated, for any reason, including running out of disk space, it marks the drives holding that folder as unhealthy.

  
  

  You have to complete the repair wizard to finish duplicating the unduplicated files, which follows the same rules as above. Once you can get through the wizard successfully then everything will be duplicated.

  
  

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  Now from what I understand, you're saying that DrivePool refused put files on some drive that had plenty of space?

  
  

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  An import drive wizard? Hmm... easy enough to write.

  
  

  Keep in mind that a drive part of the pool can have pooled and non-pooled files on the same drive, so it's not like you loose anything from a drive added to the pool.

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• Shane

  July 2011 Resident Guru

  "Now from what I understand, you're saying that DrivePool refused put files on some drive that had plenty of space?"

  
  

  If I'm parsing reded23's post correctly, the problem is that while DrivePool was duplicating the files, *one* of the disks in the pool ran out of space, but rather than automatically switching to *other* disks in the pool which still had plenty of space, instead DrivePool stopped duplicating (and had to receive a manual repair order before it would duplicate using the other disks in the pool).

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• reded23

  July 2011 Member

  Shane is correct....but Alex are you saying because I turned on duplication after the files were on the disk this happens ? Surely it shouldn't ? and when a disk fills it moves on to the next (2 at a time)

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• Alex

  July 2011 Covecube

  Shane is correct....but Alex are you saying because I turned on duplication after the files were on the disk this happens ? Surely it shouldn't ? and when a disk fills it moves on to the next (2 at a time)

  New file placement is fairly simple in DrivePool. A new file gets created on the disk with the most free disk space. For duplicated folders, two files get created on 2 separate hard drives with the most free disk space.

  
  

  This has the effect of filling up your drives evenly.

  
  

  So under normal circumstances you should not run out of disk space for folder duplication until all the drives are full.

  
  

  But there are situations where your available duplicated free space is less than the combined free space of all the drives. I will give you a simple example,

  
  

  Disk1: 10 GB

  Disk2: 100 GB

  
  

  If both of the disks are free, how much duplicated bytes can you write?

  
  

  10 GB

  
  

  It can get more complicated.

  
  

  Disk1: 10 GB

  Disk2: 20 GB

  Disk3: 40 GB

  
  

  Available duplicated space? 

  
  

  DrivePool M3 calculates this automatically for your combinations of drives, depending on how they're currently filled up. You can see a simplified overview of this on the drives tab if you don't select anything.

  
  

  Sometimes the drives are evenly matched and you can utilize 100% of their space for file duplication. In that case, free space is free space and you won't see a difference.

  
  

  In order to optimize file placement and maximize available free space you can balance your pool. DrivePool will automatically balance the pool if it gets too out of balance.

  
  

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  Bottom line,

  
  

  If you have free space on 2 separate hard drives in the pool and you can't copy a file to a duplicated folder because it has run out of disk space then this is a bug.

  
  

  2 or more partitions on the same hard drive don't count as separate drives. They are considered the same drive as far as duplication is concerned.

  
  

  Let me know if this happens and I will investigate.

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