Hello Everyone,

 

New here and I am very interested in unRAID and have some questions.

 

[*]The device limits for the licenses is storage devices?  Amount of drives that can be connected to the system?

 

[*]How well do Atom processors work with unRAID?  I don't plan on doing anything heavy, at most Plex with 2 users streaming and some form of owncloud.  Processor in question is Intel® Atom™ Processor C2750 with 16GB ECC memory.

 

[*]Is Raid 5 their only option for redundancy?  Is it possible to add another parity device?  I get slightly overprotective of my data, so in my current setup I am using RAID 10.  Unless there is something I am missing about unRAID Array setup, it's basically a Raid 5 right?

 

[*]When the cache becomes a cache-pool, does it gain redundancy?

 

[*]Is it possible to replace the parity disk?  I currently have 4TB drives to initially start the array.  When I start adding 6TB disks, will I need to replace the parity disk without losing data?

 

The biggest reason I am asking these questions is because I am planning to move away from FreeNAS.  Works great, but the GUI and the amount of work needed to expand a zVol is a pain.  Jails were ok, always had issues with networks.

 

Thanks for all the help.

I'll give this a shot:

 

1.Yes the licenses limit the amount of drives you can attach to your system within your raid array.

2.I imagine they should work fine, but not very well for any transcoding Plex might do, that would be out of the question.

3.There is no RAID 5, UnRaid does not stripe parity across all disks, it has one disk dedicated to parity. The ability to add a second parity disk is coming 'soon' in the next release 6.2

4.No, not unless you put them in a RAID 1 array outside of UnRaid.

5.Yes there are articles on how to replace the parity drive when you want to upgrade it or if it fails.

 

There are some users on here who have moved away from FreeNAS and Snapraid, perhaps they can chip in and help you out.

 

AM

unRAID is not RAID. No striping, each disk is an independent filesystem. Disks can be different sizes. Only 1 parity currently but dual parity coming soon. Replacing any drive is easy, parity must be as large or larger than the largest data drive.

 

Cache pool is raid1 btrfs mirror.

 

Merged your threads.

1. A rather long discussion of the current license policy is here, but I believe the restrictions apply to all disks attached to the server. This would include cache, parity, array and any unmounted drives.

I'll give this a shot:

 

 

Had a feeling that was it for devices, just had to ask.  Wasn't expecting much out of that Atom.  Thanks.

 

unRAID is not RAID. No striping, each disk is an independent filesystem. Disks can be different sizes. Only 1 parity currently but dual parity coming soon. Replacing any drive is easy, parity must be as large or larger than the largest data drive.

 

Cache pool is raid1 btrfs mirror.

 

Merged your threads.

 

That is actually pretty interesting.  Is there any documentation on the file system that unRAID uses?  Guess now I have some use for my extra SSDs.  Thanks

UnRaid can use any of the following file systems for its array:

 

BTRFS

XFS

ReiserFS

If you use user shares it will give the "appearance" of striping even though it's actually filling up one drive at a time it's great for managing your plex libraries as shown in the video below

 

BTRFS

XFS

ReiserFS

 

Thanks, I will need to look into those.

 

If you use user shares it will give the "appearance" of striping even though it's actually filling up one drive at a time it's great for managing your plex libraries as shown in the video below

 

I watched that earlier, pretty interesting.  My biggest concern is what happens when a drive fails, or when multiple drive fails.  Reading some documents now, but I guess the data on that particular disk becomes inaccessible until that disk is replaced.

  Reading some documents now, but I guess the data on that particular disk becomes inaccessible until that disk is replaced.

Not at all.  unRaid will emulate the dead drive until you replace it.  Once dual parity comes out, then unRaid will emulate up to 2 drives at once.

 

Big huge advantage to unRaid is that if you ever exceed its tolerance level (currently 1 drive down soon to be 2), you will only lose the files on that drive.  A traditional RAID system if you exceed its tolerance level, you've lost 100% of your files.

Not at all.  unRaid will emulate the dead drive until you replace it.  Once dual parity comes out, then unRaid will emulate up to 2 drives at once.

 

Big huge advantage to unRaid is that if you ever exceed its tolerance level (currently 1 drive down soon to be 2), you will only lose the files on that drive.  A traditional RAID system if you exceed its tolerance level, you've lost 100% of your files.

 

Oh nice.  So it works in a sense of RAID 5(6) where the tolerance is 1(2) but doesn't write the parity across all disks.  This in turn would reduce the workload of said disks since not all of them have to be active for the parity to be written or be rebuilt.  Might make the switch over to unRAID sooner than I thought.  Just need to some research on filesystems.  Thanks.

In 'normal' operation, when reading from a file only the disk containing the file needs to be spun up (all other disks can be spun down).  When writing a file only the disk containing the file and the parity disk need to be spun up.

 

In 'failure' mode where you have had a disk fail, all other disks must be spun up when reading or writing a file in order for the failed drive to be emulated.

 

When rebuilding a failed disk, creating the parity disk or checking the parity disk all disks is are spun up.