Hello.

 

I currently have several readynas and buffalo system but I am tired of wasting a hard drive on these little 4-drive system and their larger drive systems are too costly. I only have video and music files and do not need all this corporate applications they have on it.

 

I have some questions on how the unraid system worked and how safe it was to use.

 

1. Can you recover from the software on the USB crashing or the motherboard, SAS controller breaking? In other words, can you just place it in a new computer and run a backup of the software? In other words, how resilient is the setup? 

 

2. How much space do you get off the drives? It is like with RAID 5 where you loose 1 drive to parity? For example, if I had 8 X 2TB drives, would I have 14TB of protected space out of the 16TB in the system?

 

3. Can I use sata port multipliers in the system?

 

4. I read that you can use uneven sizes of hard drives, does it basically treat the entire array hard drive at large as the smallest drive? For example, lets say you have the following hard drives, 1TB,1.5TB,2TB and 3TB drives in the system. Does it act like you have 4 X 1TB drives?

I am trying to figure out if its like Drobo(beyondraid) or more like Readynas( X-raid).

 

5. Is there any type of recovery utility that provided you have your hard drive labeled correctly, can read the data off each drive in the event of a hardware crash.

 

Thanks for your help.

 

1.  Yes and yes.  USB drive dying requires a license reissue (threads around about that).

 

2.  No - you get the full space of each and every drive (except the parity/cache drives of course), and they maintain their own file system (so you could effectively pull out a drive, stick it in a USB caddy and plug it into a Linux box and read the contents.)

 

3. Yes, plenty of discussion on that around the forums - I suggest looking at threads like Johnm's Atlas build in the UCD forum for some nice, all-encompassing info.

 

4.  No - you get the full space of each drive.

 

5.  See #2.

 

BQ

Full explanation of question 4:

 

The largest hard drive has to be used as the parity drive.  Thus the 3TB drive becomes the parity drive.  The 1TB, 1.5TB and 2TB drives will be used as the data drives.  The total data space is 5.5TB.  As a point of explanation (since apparently, you posted with much research), if you add a second 3TB drive at a later date to this array, you would have 8.5TB of storage space.  As I recall, there is a maximum of twenty data drives allowed. 

 

Reason for Edit:  to correct my inability to add!!!!  4.5 was 5.5  and 7.5 was 8.5    Thanks to BetaQuasi and Lionelhutz for seeing my mistake. 

Sorry, but to clarify, he'd have 7.5TB.

 

1+1.5+2+3+3 - one 3TB for parity (always largest).

 

Just to avoid confusion

 

 

 

Full explanation of question 4:

 

The largest hard drive has to be used as the parity drive.  Thus the 3TB drive becomes the parity drive.  The 1TB, 1.5TB and 2TB drives will be used as the data drives.  The total data space is 5.5TB.  As a point of explanation (since apparently, you posted with much research), if you add a second 3TB drive at a later date to this array, you would have 8.5TB of storage space.  As I recall, there is a maximum of twenty data drives allowed.

 

You're adding 1T to much. 4.5T and 7.5T total.

 

Thank you for all the replies. I have also watched a few video on unraid after posting my comment.

 

It seem like this system is better than Raid5 because you have the same level of disaster recovery of being able to recover from a drive lost however you can actually read information from each drive on a computer whereas with raid 5, the information is stripped. Plus being able to use uneven size drives and get 100% of the space available(after parity drive) is a big freaking deal. I have tons of uneven drives in my house that I would love to incorporate into a raid system. So this system is closer to a Drobo than a Readynas as far as using uneven drives.

 

If this system works the way it claims so, why would anyone use Freenas or raid5 instead of unraid?

 

Thanks.

If this system works the way it claims so, why would anyone use Freenas or raid5 instead of unraid?

The main reason is speed.  RAID5 writes will be noticably faster than writes to an unRAID drive.  For most of us the write speed is on no concern as we use the mover to move the files to the parity protected array or we just don't care all that much.  So long as our 1080p blu-ray movie backup plays back correctly we are happy campers.

There are always reasons people chose different solutions. For example;

RAID5 - speed

Freenas - it's free