New Build planned - Many questions

Hi,

I've been searching throughout the forums to gain a better understanding of OVM and the best way to configure it for my purposes. These questions span several topics, so I'm posting here in General Configuration discussions.

Here are my goals at this point. I currently have a Windows server cobbled together for my media but I need a purpose built installation, and it's running out of space in the case.

• This is to support my media for my Kodi installations, space for my photos in RAW format, and Documents.
• I have PVR'd media and it will continue to grow.
• I'd like to leverage the Crashplan plugin to backup my Photos and Documents, not my other media.
• One SAMBA share for each media type is my ideal goal. PVR'd TV, Backed up Movies, Backed up Music, Documents, Books, and Photo's
• I'd like to be able to survive 1 HDD failure, possibly two. I have had an HDD fail, not fun.

I recently purchased a 12 bay case, 3 2.5's and 8 hot swaps on the front.

I'm trying to understand file structure setup, parity using SnapRAID for redundancy, and adding new drives.

I suspect the recommendation is EXT4, so let's set that as an assumption.

Visualizing helps me, so I'm going to draw this out in a way here. Hopefully someone can use this to demonstrate structure and configuration. I'm a bit fried with 12-14 hours/7 days a week on an ERP project at work, so please be patient with me.

Here's the physical drives. Let's say 1 120 GB for OVM then 6 of the 8 hot swaps filled.

• Internal - sda0 - 120GB 2.5inch SSD for OVM/OS/Plugins
• Hot Swap 1 - sda01 - 4TB
• Hot Swap 2 - sda02 - 4TB
• Hot Swap 3 - sda03 - 4TB
• Hot Swap 4 - sda04 - 4TB
• Hot Swap 5 - sda05 - 4TB
• Hot Swap 6 - sda06 - 4TB
• Hot Swap 7 - Empty
• Hot Swap 8 - Empty

So as I THINK I understand it, SnapRAID uses a parity disk. So instead of striping across all disks, we reserve 1 to maintain the parity bits.

• Is this correct?
• Is there a limit to the max number of drives for 1 parity drive.
• Does that leave me with 20TB(5 Drives) of usable space?
• Would anything be gained by adding another parity drive in the above scenario?

File structure -

• Is it possible to set up 1 share for each media type, then OVM manages it across the disks? Not sure of the terminology, virtual disks?
• Or do I need to define shares on each drive. ie..
  
  
  • Assuming sda01 is dedicated parity
    
    
    • sda02
      
      
      • PVR'd TV
    • sda03
      
      
      • PVR'd TV
    • sda04
      
      
      • Backed Up Movies
    • sda05
      
      
      • Backed Up Movies
    • sda06
      
      
      • Photos
      • Audio
      • Documents

That kinda cramps things if one category starts growing faster than expected.

Adding drives. Is it as simple as putting in an additional drive and mounting it?

Back to the setup above with the two empty Hot Swaps. I have my media sitting on a Windows Server today with NTFS. Is it possible/safe to take out each of those drives, plug it into an empty hot swap, then transfer the contents over to the new drive space? it would definitely be the fastest method.

I'm in no rush, at least a month away from purchasing the rest of the hardware. I just want to attempt to set this up the best way possible for my situation on the first try.

Thanks for your patience and guidance in advance.

I'm dead tired, I probably won't be back on until the morning to respond.

Zitat

Big question... Is the server going to run 24/7 with battery backup?

On the shopping list.

Do you have any more info on an implementation of unionfilesystem in OVM? I'm guessing I would run with SnapRAID, then put a unionfilesystem on top of that? How does ufs manage writing data? So when I put a photo in the PHOTOS directory, ufs selects the physical drive to place it on or does it stripe? One of the benefits, as I understand it, of SnapRAID is that it only spins up the drive the file is on where other RAID solutions will stripe and spin them all up for read/write. So with SnapRAID, if you lose a drive, you only lose the files on it, not across all striped drives.

ryecoaaron - Thank you SO MUCH for clear and concise answers, as well as your patience with my questions. I'm going to dig into mdadm a bit as well. I will have more questions, I'm sure.

I'll be back when I can focus, too much going on with work today to delve into all of it and think straight.

The final parts should be here Friday! I plan to dive in this weekend.

It's a good day!

Machine is setup and OMV is installed. I've installed OMV-Extras as well. I haven't mounted the 4 - 4TB drives yet...

So next steps, I'm guessing.

• Mount the data drives
• Configure Snapraid
  
  
  • Select Parity Drive
  • Then Content on one drive + data
  • Data on the other two.
• Then install and configure UnionFilesystem?
  
  • Setup shares via UnionFilesystem? Or OMV will see only 1 drive for data at that point and set up my shares that way?

Are there any recommendations/best-practice folder structures people use?

When configuring mergerfs, do I include the parity drive or just the data drives?

Nevermind, only data. I see how it works now!!! This is damned awesome!!!

Small donation coming! I'll have to make it a habit to donate regularly so the devs can keep up the great work and to help offset hosting costs.