So,

 

I am enjoying the simplicity of UNraid but I have a problem with trusting my data to a data recovery method that I have never seen in action.

 

For me I cannot trust he concept of parity to work only when the need arises.  So tomorrow I guess I will have to set up a 250 GB drive, move some files to it, pull it and replace with a 500 GB drive that I have and let it rebuild.  This is the only way I can trust this set up.

 

Can I simply drag and drop some files to my disk2 (250 GB drive) and then pull it? I assume so.

 

Kryspy

Been there.

 

I did almost exactly the same thing.

1. Put some files on a drive for whch I had calculated CRC codes.

2. Shutdown unRAID

3. Pulled the drive (1TB)

4. Inserted new drive (2TB) in exactly the same place the 1tb drive was connected.

5. Started unRAID

6. Probably had to manually start the array, don't remember for sure.

7. unRAID rebuilt the 1TB partition from all other dirves in the array and then expanded the file system to the full capacity of the 2TB drive.

8. Checked the files against the CRC codes. All were good.

 

I did nothing to change the drive configuration. unRAID detected the new drive and did the recovery without my having to do a thing. It automatically updated the disk slot to reflect the new drive. In my case the new drive had been erased to all zeros using a disk wipe utiltiy in another computer to break it in, so to speak. I don't know if unRAID would have done anything differently if the 2tb drive I put in to replace the 1tb actually had data on it. Maybe someone with more experience knows the answer to that.

Really want to test it?

Put a couple of drives in and let it build your parity.

Play a movie and then for the heck of it pause your movie

pull a power cable on the drive that has the movie.

 

I did and the parity drive took over and played the rest of the movie just fine.There was a little bit of a skip, but hey it worked fine after that.

 

Turn off your machine and rehook backup your drive and then turn it back on. Your machine will tell you there was a problem and then it will start to rebuild the drive that you unplugged.

kizer,

 

Now that really sounds like fun.  Gonna give that a go after parity finshes.

 

Kryspy

Yes, seeing the system serve up data from a drive which is not physically present, is fairly convincing!

Believe it or not when I first came here I was very disbeliving. I took a

3ghz machine I have laying around

120gig Sata

10gig IDE

6gig IDE

 

I ran it through Joe L's preclear script just because everybody kept talking about it.

120gig passed

10gig IDE failed

6gig IDE passed

 

Loaded it up and let it rip. During the pairty build it kept telling me that the 10gig drive had issues. Of course I knew it did because the preclear script told me it would.

 

Installed a movie on that bad drive and played it a few times. Ran the parity check again and it had the same errors so I knew the error checking was doing what it was supposed to.

 

Got crazy and pulled the power plug. Started the video up again or maybe I unpaused it I can't really remember now. Worked so I was convinced that the machine would protect its self.

 

Installed another drive of simular size and all be damned it rebuilt and I was good as new. Well old junk, but it recovered LOL.

 

Now I'm running with a bunch of drives listed in my signature. I still have two drives full of my movies and TV shows sitting on a shelf just in case, but I currently have zero issues. Oh make sure you get a good quality UPS. Nothing worse than losing power during a write. Would cause parity issues.

There are lots of ways to test out unRAID, all of the above are good suggestions.  Also keep in mind that every time you upgrade a drive you are simulating a failed drive.  unRAID doesn't care if the drive died or if you just unplugged it, the only thing it knows it that a read from or write to the drive failed.  As soon as this happens, unRAID will start to simulate the missing drive (and you will lose parity protection until the missing drive is replaced).

 

Here's another test for you, let's call it the 'worst case scenario' test.  Say you have some catastrophic electrical storm that manages to get a surge to your server and blows out your power supply, flash drive, mobo/cpu/ram, and two or more of your hard drives (meaning that you can't rebuild from parity).  Basically, you don't know which drives are good (if any) and which ones are bad.  Here's the solution: build a second unRAID box and prepare a second flash drive with unRAID Basic (the free version).  This second box can be your normal desktop that you just boot from the flash drive instead of from your normal boot disk.  Now, plug in your suspect hard drives three at a time and assign them all as data drives in unRAID basic.  DO NOT ASSIGN A PARITY DRIVE.  Start the array without parity.  Browse each drive via disk shares, and you will see all your data on the healthy drives.  If one drive shows up as unformatted, it is your parity drive and it won't contain any data.  The moral of the story - unRAID doesn't use striping, so each of your healthy data disks is individually safe even if you suffer a multiple drive failure.

Amen,

 

Even if you loose data you don't loose all of your data.

Even if you loose data you don't loose all of your data.

 

You should never let your data loose, keep it fenced in.  That's why hard drives are made of metal!  If they were made of cheese or grass or something else the data could escape.

Even if you loose data you don't loose all of your data.

 

You should never let your data loose, keep it fenced in.

 

Haha ... that reminds me of my mother - born a German, but naturalised British, she lived in UK for more than 50 years.  Her English was perfectly good, except that she always had problems with 'choose' and 'chose'!

LOL

 

Loose, lose, loss. Grrrrrr