I am running 4.5 sorry for posting in the 4.4 forum but did not see a 4.5 forum.

 

I have a 500gig drive that has reported write errors (4) and has been taken offline by unRAID.

 

I wish to replace it with a 2TB and also replace the parity drive with a 2TB (WD Green) - so I have two new 2TB drives I wish to install into my unRAID.

 

Per instructions this is what I am planning to - just wanted to check with you experts appreciate the feedback.

1. Are these the correct steps?

2. Is there anything else I should do?

3. Is there a way I can replace the parity drive with 2TB and the failed drive with 2TB without this intermediate step of swapping the parity drive to be a data drive? ie: end up with 2TB in the array and 1 bad and 1 good 500gig drives that I take out of the array.

Before doing any of this I am running extensive tests on the new 2TB drives to make sure they are good. Have been having some bad luck with WD drives lately.

 

1. Stop the array.

2. Power down the unit.

3. Replace the parity hard disk with a new bigger one (replace 500gig with 2TB) (Physically swap the hard drives)

4. Replace the failed hard disk with you old parity disk (replace bad 500gig with parity 500gig) (Physically swap the hard drives)

5. Power up the unit.

6. Start the array.

 

THEN once the rebuild is complete yank out the old parity drive which is now a data drive, and replace it with a new 2TB drive with the following steps.

 

1. Stop the array.

2. Power down the unit.

3. Replace the failed hard disk with a new one. (replace 500 gig with 2TB)

4. Power up the unit.

5. Start the array.

 

The bad drive is disk 3 in the attached image.

That is called "parity swap" & it does work if everything goes right. If you get one hiccup then your data is hosed on your 500 gig drive. Been there did that. If you search the forums you will see that I tried just that & lost massive amounts of data.

 

Your best bet would be to copy everything off of your 500 gig drive to other drives in your system. You can use midnight commander for this. It is built into unRaid. That's the beautiful thing about unRaid. You can access your data even though the drive is in a degraded state.

After the copy is complete you can remove the 500 gig drive & hit the restore button. This will remove the 500 gig drive from the config files.

Then replace the parity drive with your new 2 TB drive & generate parity. Make sure to check parity afterwards to make sure it is correct.

Then install the other 2 TB drive & run Joe's pre-clear script to make sure the drive is fine. Of course you can also do this to the parity drive if you wish to test it.

 

This is much safer than doing the parity swap procedure. I hate to see you lose data if something goes wrong.

 

Phil

3. Is there a way I can replace the parity drive with 2TB and the failed drive with 2TB without this intermediate step of swapping the parity drive

Basically, no.   You must go through the parity-swap process if the replacement drive is bigger than your existing parity drive.  Once it is done, then you can swap out the older/smaller parity drive, now being used as a data drive with the larger data drive.

 

Or, you can copy the files off of the 500 Gig drive to other drives as PhilH described, un-assign it, press "restore" to save a new disk configuration, rebuild parity without it, then proceed.  The parity swap procedure depends on everything else working properly.  (But then so does the data reconstruction of a failed drive)

 

Make copies of any critical files on any of your disks... the likelyhood of you dislodging a cable, or inducing a static charge and causing ESD damage while swapping hardware is very high.  Wear a grounding wrist strap when working in your server.

 

Joe L.

 

Thanks guys talk about a prompt response! - was planning to back up the data. Sounds like taking the drive out. Adding the parity drive (2TB). Then adding the new 2TB data drive in.

 

I have a follow up question - on CPU.

 

I am currently running on an old P4 with 512mb of RAM ( I think - its been 2 years since I opened this box up - this is one of the best things about UNRAID - set it up and forget about it - except for the parity checks (which I have to confess I have not been religious about - but I see a script to automate it which I will adopt). Any case so question is: is a P4 with 512mb of RAM sufficient horsepower?

 

The machine is running both SATA and PATA drives (total of 11 drives for close to 6TB of storage (with the 2x2TB I am adding) - if that matters.

Machine ONLY runs UNRAID - nothing else.

 

Any case so question is: is a P4 with 512mb of RAM sufficient horsepower?

 

The machine is running both SATA and PATA drives (total of 11 drives for close to 6TB of storage (with the 2x2TB I am adding) - if that matters.

Machine ONLY runs UNRAID - nothing else.

 

A p4 with 512Meg of ram is fine.  Your server sounds a lot like mine, an older Celeron CPU with 512 Meg of ram.

Backed up.

Unassigned Disk3

Restored

Doing parity sync now

 

INSTEAD

 

I was wondering if I backed up.

Unassigned disk3

THEN replaced the parity drive

Restored

 

Would I not have saved one whole parity sync?

Once the parity sync is complete with no disk 3 - its going to take 10hrs!

 

Can I then add disk3 AND the parity drive at the same time? or do I have to add the parity drive sync (10hrs) then add the new disk 3 and resync (another 10hrs)?

Once the parity sync is complete with no disk 3 - its going to take 10hrs!

 

Can I then add disk3 AND the parity drive at the same time? or do I have to add the parity drive sync (10hrs) then add the new disk 3 and resync (another 10hrs)?

You can do them both at the same time.  You'll need to press the button labeled "restore" to save the new disk configuration. It will then do a full parity calculation.  You'll be presented with a "Format" button when you start the array if the new disk3 is not formatted.

Cool thanks! Saves me 10hrs

Update:

So you know how they say anything that CAN go wrong WILL go wrong!

 

Turns out my motherboard is a A7n8X running an Athlon XP chip at 2405Mhz *slightly overclocked if I remember.

And the onboard SATA controller is a SiI 3112A which does not recognize the 2TB parity drive!

 

So I had to shuffle some drives about moved the parity drive to the PCI promise controller - (what impact on performance I wonder?).

 

Luckily saved all screens and took notes while doing this so remapped the drives to the right disks (cross fingers) start the array.

 

Screen flashes UNFORMATTED for all drives! Holy crap! Deep breath, REFRESH.

Only shows new 2TB unformatted. Phew!

 

Pressed Format.

 

Now it looks like it is doing the format first BEFORE rebuilding the parity drive - which would make sense.

 

Wow and it looks like the server is functional even in this state. I tried a user share took a while to populate (its across multiple disks) but it works!!!

 

Ok does anyone know what Tom (the author of this app) did before he wrote this? Amazing!! How resilient!!! I am impressed I truly am.

 

Shall post one more once all drives are online just to close the loop.

 

Think I am going to take a performance hit because the parity drive is now on the PCI bus? Or was it on there anyways with the SiI controller? I am not THAT technical to know. But technical enough to care .

 

YES! Format complete Parity sync going on but look how long it shows for estimated finish! 2968.9 minutes! Thats 49 hours! 2 days for a synch.

 

I guess I took a major performance hit eh guys? 10 hrs to 2 days for a a sync anything I can do other than get a new motherboard?

 

See attached for new config and I still have 2x500 gig SATA's in hand! Hmmm what to do what to do... save up for a new motherboard thats what!

 

THANK YOU for ALL YOUR HELP!

YES! Format complete Parity sync going on but look how long it shows for estimated finish! 2968.9 minutes! Thats 49 hours! 2 days for a synch.

 

I guess I took a major performance hit eh guys? 10 hrs to 2 days for a a sync anything I can do other than get a new motherboard?

 

See attached for new config and I still have 2x500 gig SATA's in hand! Hmmm what to do what to do... save up for a new motherboard thats what!

 

THANK YOU for ALL YOUR HELP!

It won't take anywhere near that time.  That would be the time if all your drives were the same size.  Since most are smaller, the rate will increase dramatically once parity is past the size of the smaller drives.

 

Joe L.

You are right it didnt take 2 days. Took about 12 ~ 14hrs. Not bad.

One last post to help anyone who is looking at CPU replacements etc.

 

My machine is running an Athlon XP-M 2500+ Barton with an original clock speed of ~1.8Ghz over clocked to 2.4Ghz - the chip was under $100 when I bought it in 2004 - it has been working for 6 years and been in my Unraid server for 2 years - running non stop 24/7. 

You are right it didnt take 2 days. Took about 12 ~ 14hrs. Not bad.

Now that you've written the initial parity calculations, you should perform a manual parity check to ensure your server can read the parity disk properly.

My machine is running an Athlon XP-M 2500+ Barton with an original clock speed of ~1.8Ghz over clocked to 2.4Ghz - the chip was under $100 when I bought it in 2004 - it has been working for 6 years and been in my Unraid server for 2 years - running non stop 24/7. 

You don't even need to overclock that.  Its stock speed should be plenty.  My "M" is running at 1GHz.