Drive Upgrade Best Practice

[brent3000]

Hoping this is something I can source some ideas from everyone on the best course of action or suggestions on how to proceed.

 

This is my first full blown server for home which I was doing on the cheap as best I could, in doing this i was using a bunch of older Hard Drives (6x2tb) 

 

Now I have recently got 3 x 14TB drives in the Amazon sales which I'm looking to slot in and replace some of the 2tb drives with (so the parity drive and 2 additional older 2tb drives)

 

Note - Drives currently are at 50% capacity 

 

Now from what I have experienced in this shorty time, when a drive is replaced the system will pretty much initialise the disk and 'zero' the whole thing out before its re-writes the data.

 

Now I have three drives, so the parity drive would need to be a complete re-build, but also as I slot the additional drives in it will have to clear the drives and then re-write any data from them.

 

Would I be correct in saying I would need to re-write the system 3 times (1 per new disk?) or is there a better more efficient way to do the drive swap out?

[trurl]

2 hours ago, brent3000 said:

Now from what I have experienced in this shorty time, when a drive is replaced the system will pretty much initialise the disk and 'zero' the whole thing out before its re-writes the data.

No that isn't at all what happens with a replacement. It rebuilds the data from the parity calculation, no zeroing or anything else. It has to rebuild the whole disk all the way to the end, even if the original was smaller. All of the replacement disk must be in sync with parity.

 

Just replace each disk and let it rebuild.

[brent3000]

19 hours ago, trurl said:

Just replace each disk and let it rebuild.

But as one of the disks will be the parity it will have to rebuild the parity drive and then ill have to load each drive?

 

So it may take several days to replace each disk (being 14tb ea)

 

Based on that also it would only really hammer the drive being replaced then based on that? (Apart from replacing the parity drive which would have to rebuild from all the drives?) 

[trurl]

Whether rebuilding parity disk or data disk it's the same. 

 

Read all other disks to get the result of parity calculation then write that result to the rebuilding disk. 

[hawihoney]

On 11/10/2020 at 12:24 PM, brent3000 said:

Would I be correct in saying I would need to re-write the system 3 times (1 per new disk?)

It will not rewrite the system, it will rewrite a replaced disk. And yes, you'll need to rebuild these three new disks one after another. Start with the parity disk.

 

[brent3000]

Thanks for the into, the reason I'm asking is one of my drives started to show 187 on the SMART and I was worried having a rebuild of the parity drive 'may' cause the drive to throw some errors or issues ontop of my sata port 1 causing the system to crash (its one of the Cache drives so a rebuild should not impact this but the board's in the RMA process, just gotta watch what i write to the cache to avoid the thing falling over ) 

 

I'm doing my final drive checks so this weekend ill kick off the parity replacement with the 14 TB and make my way through the replacement drives

 

Cheer for the help all,

[hawihoney]

187? Uah, that's bad. In that situation I usually would replace that bad disk first. You need a 2 TB replacement disk for that step.

 

IMHO this is a bad situation. There's a safe way and a risk way. I always go the safe way (see above).

 

Edited November 12, 2020 by hawihoney

[trurl]

4 hours ago, brent3000 said:

one of my drives started to show 187 on the SMART

This is the first mention of an actual possible problem and not just a discussion about upsizing disks.

 

Go to Tools - Diagnostics and attach the complete Diagnostics ZIP file to your NEXT post in this thread.

[tuxfania]

I did this a while back and used this method...

 

Install Unassigned Devices and attach an external USB drive large enough to hold the data in your shares

Copy all of the data from shares to the external drive

Put in your new drives and assign as desired...hold off on assigning parity for now

Set up your disks/shares as desired

Copy data back to shares from the external drive

Assign parity and let it rebuild

 

I liked this method because I had a copy of my data on external USB and the disks I removed prior to the upgrade of the drives.

 

Also, waiting to assign parity made the copying of the data back to the Unraid server faster...let it rebuild parity after the copy

 

[brent3000]

See attached glados-diagnostics-20201113-1205.zip

 

I don't currently have any spare slots to connect both drives at once (unless USB work for it?)

 

As it stands now the problem drive already has no data on it as I moved it all with Dolphin recently when it first started getting issues (It had two errors at first but since only now SMART 187 is present) 

 

This is how the drives currently look (Disk 1 being the error child) and already has no data on it as present (the 1% is a random 14GB i cant seem to find what it relates to, I assume filesystem of sorts?)

 

I'm almost keen to rip out the parity drive and drive 1 and smash the build twice hahah, but I bet thats gonna be worse in practice sooo yeah  prob wont be doing that 

[trurl]

(Tried to post this last night but apparently there were forum problems)

 

If the disk has no data no need to include it in the rebuilds.

 

Shutdown, install new parity and new disk1, reboot then

 

Go to Tools - New Config, keeping all other assignments, assign new parity and new disk1. Start the array to begin parity rebuild. After it finishes you can format new disk1.

 

Then proceed with rebuilding each of the other disks with larger disks, one at a time.

 

 

[brent3000]

Thanks for the info,

 

So reading this correct, I can replace disk Parity and Disck1 and let it rebuild then add the third disk and all should be good?

aka install two drives at once should be issue free? (as parity rebuild always has a risk linked to it and drive1 is already dead/empty?)

[ChatNoir]

If I understand how it works correctly, for your second step, adding a new drive should not rebuild parity.

Unraid clears the disks and it's content amount to 0 in the parity calculation (except for the file system overhead I guess).

 

Only once you start to add data to the drive the parity will be updated.

[trurl]

1 hour ago, brent3000 said:

then add the third disk

 

1 hour ago, ChatNoir said:

adding a new drive

And here's where we need to clarify terminology. 

 

I was under the impression you wanted to replace, not add

[ChatNoir]

10 minutes ago, trurl said:

 

And here's where we need to clarify terminology. 

 

I was under the impression you wanted to replace, not add

You are right, I assumed that:

1 hour ago, brent3000 said:

I can replace disk Parity and Disck1 and let it rebuilt

was about New Config without new parity and without "Disk1". Then rebuilding Parity.

When that would be done, add new drives. I should have clarified this.

[trurl]

OP has 1x2TB parity + 5x2TB data to start, disk1 has issues but no data. Wants to replace parity, disk1, and another disk with new 14TB disks. 

1. New Config with new 14TB disks assigned as parity and disk1, all other disks assigned as before, let parity rebuild. After parity rebuilds, it will be in sync with all the disks in the array, including new disk1.
2. Format new disk1, which writes a new empty filesystem to disk1. This write operation updates parity accordingly just like any other write operation in the array.
3. Replace/rebuild another disk with the remaining new 14TB disk.

For simplicity, I have left out any discussion of preclear. In this scenario, preclear would be strictly for testing purposes, since Unraid only requires a clear disk when ADDING a disk to a NEW slot in an array that already has valid parity. No disks are being ADDED, just REPLACED.

 

I personally don't bother with preclear, but I have good (enough) backups, am careful (with connections), diligent (Notifications), and only put a single new untested disk into my array occasionally. Since there will be 3 new untested disks going in you could make an argument for testing.

[trurl]

5 hours ago, trurl said:

New Config with new 14TB disks assigned as parity and disk1, all other disks assigned as before, let parity rebuild.

Just an edit of above wanted to make sure wasn't missed. 

[brent3000]

Yes sorry for the miss wording on some of it, always got to get the words correct hahaha

 

But yes total of 3 drives are to be replaced long term.

 

I'm already doing some drive tests with HD Sentinel so I will have enough data to be sure the drives wont early fail so I wasn't planning on preclear personally.

 

Thanks all for the help and guidance, will post back is I get stuck but 'should' be good from now

[brent3000]

Ok so i finally got the drives installed (took awhile to finish the write and pass on the system) but its not letting me save the settings of the system? 

 

 

The drives are installed and the format button is grey

 

When i assign the drive it shows no way to apply and rebuild the settings?

 

 

The only options i have in the operations is reboot and shutdown as start is shows too many things wrong 

 

 

 

[brent3000]

On 11/14/2020 at 3:51 AM, trurl said:

Go to Tools - New Config, keeping all other assignments, assign new parity and new disk1. Start the array to begin parity rebuild. After it finishes you can format new disk1.

It would seem I did not scroll up enough and this step wasnt in your last block  so looks to be rebuilding now, only issue is disk one is showing 'Unmountable: Unsupported partition layout'

 

Update all should be sorted now, issue was device wasn't setup and needed formatting but the greyed out option was not letting me do it, but the array stop and restart kicked the format off, 

 

rebuilding now 

Edited November 18, 2020 by brent3000

[trurl]

9 hours ago, brent3000 said:

disk one is showing 'Unmountable: Unsupported partition layout'

Because it hasn't been formatted yet.

[brent3000]

build and another 14TB available  thanks all,

 

Now I'm going to really put this system to the test when I rebuild the next drive i replace