Questions re Transferring to new NAS; new machine and HDDs

[eXorQue]

Currently I have a Supermicro 1U Blade NAS (very old) with 4 HDD + 1 SSD;

• 3 HDDs 2TB storage
• 1 HDD 2TB parity
• 1 SSD 1TB cache

I want to move everything on to a new server and new disks.

The new setup will be 5 HDDs + 1 M.2 SSD:

• 4 HDDs 4TB storage
• 1 HDD 4TB parity
• 1 M.2

 

I had the following in mind, correct me if this isn't going to work. I have a few question with this approach at the end.

 

1. Add one 4TB as parity disk. Now I have two parity disks, this'll protect the data a bit more for when one would fail during rebuilding when replacing the others
2. Replace one 2TB with a new 4TB disk
3. Repeat step 2 till all disks are replaced
4. Add the last 4TB disk. As I had only 4 2TB disks, I can add the last 4TB disk as the last one
5. Remove the 2TB parity disk. Now my system is complete wrt HDDs for the new system

Questions:

1. How do I transfer from my SSD to the M.2, or should I not do that at all? How to get this part to work?
2. Can I just transfer the disks to the new system? Does it work in these steps?
   1. Transfer disks to new system
   2. Transfer Flash drive to new system
   3. Boot from Flash drive
   4. Have unraid happily running?

 

[ConnerVT]

I am one who likes to do things in baby steps, rather than doing a number of changes all at once.  Makes it much easier to diagnose and correct any issues that come up.  This is my suggestion.

 

First, Unraid handles disk assignments by drive serial numbers.  The CPU and motherboard do not matter, so you can move all of your drives to new server hardware and all should work as it did on the old hardware.  Sometimes drive controllers don't behave in the same manner, passing the drive serial number info the same.  Handling of Docker and VM is a bit more complex, so do that after getting your array in order.

 

First thing is to only start if your current system has no issues - Parity is valid and no data drive errors.  Personally, before shutting down the old server for the last time, I would set Docker, VM and Array not to auto-start to allow you to do this when you are ready to do so.  If you don't already have Unassigned Devices installed, do this before moving to the new hardware.  Also make a list of drives/serial numbers of where they are assigned (print of Main tab works) and make a local backup of your flash (Main > flash > Flash Backup) and Diagnostics (lots of good info if needed).

 

You should be able to install your old drives and new drives into the new server (assuming enough SATA ports.  If not install your current array/cache and as many others drives as possible).  When it boots, you can check your disk assignments.  All of your array/pool assignments should be the same as they were on your old server.  Your new drives should show as unassigned devices.  Start the array, and check all is working as expected.

 

Your plan for upgrading the disks in your array is flawed.  All parity drives need to be larger than the data drives in the array.  You also made it a bit more complicated than necessary.

 

First thing to do is replace the Parity Drive and let it rebuild.  You can then reassign a new 4TB drive to rebuild a 2TB dive's data.  Having the 2nd parity drive, as you suggested, is not much benefit.  The old 2TB data drive will be sitting in Unassigned Devices and is a backup of the data being rebuilt.  Repeat until you have rebuilt all of the 2TB drives onto the new drives.

 

For the Cache drive, follow the standard cache drive replacement procedure in the Unraid manual.  Typically you use the Mover to move everything onto the array, reassign to your new M.2 drive, and use Mover to move it all back.  Worst case, you may need to delete your docker image file, recreate it and reinstall your dockers (Docker > Add Container > Select Template).

 

I won't get into VMs, as they are very sensitive to major hardware changes, and I've given you a lot to chew on for now.

 

If coming from a healthy server, it really isn't all that scary or difficult.  Even easier when doing things one step at a time.

 

Edited November 19, 2023 by ConnerVT
speeling

[eXorQue]

First off, thank you for the thorough response.

 

To recap, correct me if I misunderstood, you basically mention two upgrade/transfer strategies with some presteps

 

Presteps

1. list of drives/serial numbers, print of Main tab

2. local backup of flash drive (Main > flash > Flash Backup)

3. backup of Diagnostics

 

These seem logical presteps. Thanks for that!

 

Upgrade/transfer strategies

1. move as much as possible to the new server, check disk assignments, start the array

2. replace parity drive, rebuild untill all drives are replaced

 

Or did you mean that it's part of ONE process? You mention doing baby steps, this doesn't look like a baby step to me though... Sounds more like one big massive step, moving all drives, and hoping that everything will work when you put them in the new pc.

 

A few questions/comments on things you mentioned that aren't clear to me.

 

12 minutes ago, ConnerVT said:

All parity drives need to be larger than the data drives in the array.

Understood. To be completely safe, I could use my spare 4TB as a second parity drive. Thus, first adding the 4TB as second parity, then replace the old 2TB parity with the new 4TB HDD.

 

14 minutes ago, ConnerVT said:

Having the 2nd parity drive, as you suggested, is not much benefit. 

 

I think this is incorrect as mentioned here: https://docs.unraid.net/unraid-os/manual/storage-management/#replacing-a-disk-to-increase-capacity

Quote

* If you have single parity then you are not protected against a different drive failing during the upgrade process. If this happens then post to the forums to get advice on the best way to proceed to avoid data loss.

* If you have dual parity and you are upgrading a single data drive then you are still protected against another data drive failing during the upgrade process.

It does make sense, as when you're rebuilding parity, there's no "backup" when that rebuilding is going on.

22 minutes ago, ConnerVT said:

For the Cache drive, follow the standard cache drive replacement procedure in the Unraid manual. 

I don't see that in the manual, but to replace the cache drive I could do this? (starts at 8:40) https://youtu.be/ij8AOEF1pTU?t=520

 

[ConnerVT]

1 minute ago, eXorQue said:

Upgrade/transfer strategies

1. move as much as possible to the new server, check disk assignments, start the array

2. replace parity drive, rebuild untill all drives are replaced

 

Two steps.  First is to make sure that new system can work as well as old system.  Then start swapping drives, starting with the Parity drive.

 

As for two Parity drives, this is complete overkill.  Dual parity allows for 2 drives in the array to fail and have redundancy.  Typically folks with 10+ data drives may need this.  For a small number of 2TB drives?  Not worth the bother, complexity, and adds more opportunities to do something wrong.  If you are concerned about your current drives failing you would be advised to replace them before doing this upgrade.

 

For replacing cache (Pool) drive, Spaceinvader One's video is a good tutorial (I used that the first time I did it).  It is in the manual HERE.

[eXorQue]

@ConnerVT I started moving the disks and ran into issues starting the array. Take a look at this thread, which is related to my issue, and where I commented my info: https://forums.unraid.net/topic/84717-solved-moving-drives-from-non-hba-raid-card-to-hba/?do=findComment&comment=1329471