I currently have an 8TB WHS server (16 500GB drives), and I am considering building/switching to an unRaid server.

 

I am trying to do a comparative analysis to see which system will actually perform better for me.

 

WHS's biggest advantage over unRaid is increased data security.  With file duplication turned on, there is a 100% recovery rate for a single failed drive (same as unRaid).  However, if that drive fails, all data can be recovered to *other* drives, meaning that a second sequential drive failure can be recovered from (assuming sufficient free space) without replacing a drive.  This is not possible in unRaid.  WHS also offers limited recovery in the event of simultaneous drive failure.  If two drives fail simultaneously, data duplicated onto other drives in the array can be recovered, creating a potential recovery rate of up to 100% from two-disk simultaneous failure although less than 100% is more likely (recovery % probability increases based on number of drives in array).  Unraid offers 0% recovery from a double failure, meaning that WHS has greater data security.

 

UnRaid offers significantly lower overhead.  WHS's improved data security in multi-disk failures comes at the cost of massive overhead.  To obtain this security on my 8TB server, only 4TB of storage space are actually usable, with the rest reserved for duplication.  In unRaid, this overhead would be reduced from 4TB to 0.5TB, a significant improvement in storage capacity.

 

At what point is the tradeoff of security for capacity worth it?  Am I overestimating the data security of WHS?

Are there other compelling reasons to use unRaid over WHS?

 

EDIT: To note, WHS is also nice for ease-of-use and remote administration once set up.  Having never used unRaid, is it comparable in ease of day-to-day operation to WHS?

Unraid offers 0% recovery from a double failure, meaning that WHS has greater data security.

 

That is not correct.  Data on all the other drives is still readable.

 

If you have eight 2TB drives, you have 8 TB of storage in WHS, versus 14TB in unRAID.

 

If you lose 2 drives in unRAID, the most you lose is 4TB of data on the drives that failed... the other 12TB is still there.

 

Unraid offers 0% recovery from a double failure, meaning that WHS has greater data security.

 

That is not correct.  Data on all the other drives is still readable.

 

If you have eight 2TB drives, you have 8 TB of storage in WHS, versus 14TB in unRAID.

 

If you lose 2 drives in unRAID, the most you lose is 4TB of data on the drives that failed... the other 12TB is still there.

 

 

I think I understand what he was saying.

 

If you have 2 drive failures in WHS - As long as the data is duplicated on the drives that are still working then you can reconstruct the 2 failed drives since the data is on the other working drives.

 

If you have 2 drive failures in unRaid then the data that was on the 2 failed drives is just lost. Yes the other data is still there on the working drives, but that does not help the failed drives.

 

Been there done that.

 

Phil 

If you have 2 drive failures in WHS - As long as the data is duplicated on the drives that are still working then you can reconstruct the 2 failed drives since the data is on the other working drives.

 

That is also the case in unRAID and all drive storage systems. If you have your data duplicated on other drives, you simply copy them back over to the replacement drives. No data lost. 

If you have 2 drive failures in WHS - As long as the data is duplicated on the drives that are still working then you can reconstruct the 2 failed drives since the data is on the other working drives.

 

That is also the case in unRAID and all drive storage systems. If you have your data duplicated on other drives, you simply copy them back over to the replacement drives. No data lost. 

 

Yes, but in other drive systems, it requires a user action to create the duplicate.  In WHS, duplication of files onto a separate drive is automatic, as is restoration of those files (and creation of new duplicates) if a drive fails.

Yes, but in other drive systems, it requires a user action to create the duplicate.  In WHS, duplication of files onto a separate drive is automatic, as is restoration of those files (and creation of new duplicates) if a drive fails.

WHS has the distinction of loosing all of my data when two drives died and the system could not recover from it.  It would not allow the removal of the two failed drives - probably because the backup database was on those two drives.  Yes I had duplication of the backup database turned on.  I had to reinstall WHS to get a working system which meant I lost the backups of other systems.  Needless to say I wasn't happy since coincidentally I had a third drive crash on one of the systems that WHS backed up BEFORE I got WHS completely reinstalled.  It wasn't until after this happened that I found out that the backup database could be backup up with a third party app external to WHS.

I've never used WHS but what happens if the motherboard dies?  On unRAID it's a simple matter to replace the board with the same or even different board. 

Does the duplication of files extend to operating system files as well?  What happens if the disk that WHS is installed on fails?

I've never used WHS but what happens if the motherboard dies?  On unRAID it's a simple matter to replace the board with the same or even different board. 

You can install it on another motherboard but you will have to activate again don't know how easy that is.  XP isn't bad but I've never had to re-activate WHS.

Does the duplication of files extend to operating system files as well?

No.

What happens if the disk that WHS is installed on fails?

Re-install OS but for this the activation should go without a problem.  It always has for me.  Went from 250GB to 320GB with no activation problems.

Does the duplication of files extend to operating system files as well?  What happens if the disk that WHS is installed on fails?

 

If you have a multi-drive setup, the system drive only holds OS files and "shortcuts" to all of the files in the array.  If this drive fails, you can insert a new drive and reinstall the OS.  During installation, it will scan all other drives in the array and recreate all of the shortcuts.

 

You lose any add-ins or modifications you have made to the OS, but no files are lost from the array.

You could replicate WHS mirroring within unraid for certain files if you wanted to.

 

For my irreplaceable files I use Crashplan and backup to a friends PC, everything (just) on unRAID is basically stuff that costs TIME to replace like Films and Music.

Just to add,

 

I used to use WHS as well.    On 2 different occasions (think I'd have learned from the first) it somehow managed to lose 1/2 of my mp3 files from A to P.  Meaning in almost every album folder 1/2 of the songs were missing.  If an album had 12 songs only 6 of them were there.  In my opinion and others here you just can't trust any system no matter what it claims.  Having an external solution no matter what is the only way to make sure you do not lose data.

 

Kryspy

I currently have a 6TB WHS server and a 6TB ReadyNas NV+ server and am finalizing a Unraid Pro build which will consume the data of the other two (mostly media).  The biggest factors for me were 1) HUGE scaling cost of WHS (hated the idea that my initial 20TB build would have 20TB of completely wasted space).  The larger you get the smaller the scaling cost with Unraid.  2) The low hardware requirements--I ended up building new since I wanted a big chassis and IPMI but I have lots of leftover parts and any one of them would have worked perfectly for unraid.  3)  Already mentioned but any drive loss beyond the initial first means only the data on that drive is lost.

 

This coming from a senior windows admin too. 

 

 

Drive Extender works relatively well for small files, but with large files, it wastes half of all available space. Thinking that way, I had only enabled duplication on documents, photos and music, and left videos unprotected. When a single drive failed, I lost 300GB of videos and Drive Extender took care of scrambling all my music files, exactly like Kryspy. I was able to recover my music files using a backup copy.

 

Moral of the history: data protection and failed disk protection are different things.

 

The first one is only achievable through regular backups, and the second one is better addressed by unRAID then WHS, because it uses last space for redundancy, and don't mess with your files.