Question about Drive Re-arrangement

[KentBrockman]

I have an 8 Disk Unraid Server using a Supermicro MV8 controller card.

I would like to re arrange my disks and clean up the inside of my case a little.

 

My question is:

Do I have to re connect the disks to the same ports as before or will uraid be able to figure out which disks are which?

 

Thanks in advance,

Kent

 

[Joe L.]

I have an 8 Disk Unraid Server using a Supermicro MV8 controller card.

I would like to re arrange my disks and clean up the inside of my case a little.

 

My question is:

Do I have to re connect the disks to the same ports as before or will uraid be able to figure out which disks are which?

 

Thanks in advance,

Kent

 

IF you keep the parity disk on the same port it, and use the same set of ports for the others, it will probably figure it out on its own.

 

You are best off if you take a screen-print of the "Devices" page, then you can use the "Devices" page to re-assign the drives to their logical slot in the array after you re-do the cabling.  (They can be on different physical cables/ports, and you can logically assign them to the same disk slot in the array on the Devices page) 

 

Joe L.

[KentBrockman]

Thanks for the reply Joe,

 

What do you mean by "use the same set of ports for the others"?

Do you mean keep drives that were previously connected to ports on the MB on the MB and drives connected to the MV8 on that ?

 

Thnaks,

Kent

 

[RobJ]

Do you mean keep drives that were previously connected to ports on the MB on the MB and drives connected to the MV8 on that ?

No, that is not necessary.

 

More related resources, from the FAQ:

* "How do I move my existing unRAID array to a new system?"

* "What is the safe way to rearrange disk numbers, assignments, slots, etc?"

[fitbrit]

I'm still confused about one issue:

Is it possible to rearrange AND renumber the drives? If I want to physically rearrange the drives, connect them to different slots, and renumber them so that the new numbering logically reflects which ports the drives are connected to, how do I do this? My parity drive is at the top of my case. I want the next drive to be disk1 and so on. Since the data on the drives hasn't changed, is there a way to make unRaid accept it? Should I just use the "trust my array/parity" procedure?

[WeeboTech]

Why not just re-calculate parity?

Do an initial parity check, then rewire as your heart desires, then recreate the parity drive.

 

If I was that heart set against recalculating parity, I would just rewire a pair at a time.

When unRAID comes up complaining about too many drives missing out of order, I would reset the devices page.

 

I've done this a number of times when I was testing port multiplier capability on my new RC-218 card.

 

Everyone is so against recalculating parity.

I'm surprised at times.

If people are so afraid of having a drive unprotected for a few hours then perhaps those drives should not be used.

 

You should be able to exercise your drives at any time.

I've had drives spinning for years without failure.

 

[Joe L.]

Let me try to clarify...

 

unRAID will recognize if the drives are moved...

 

As long as the parity drive remains on the same "port" on the disk controller AND

as long as the data drives remain on the same set of ports on the disk controller(s)

unRAId should present a warning something like

"Two or more disks are wrong. 

Start will  just record the new disk positions and bring the array on-line.

We recommend you start a Parity-Check afterwards just to be safe."

 

If you use NEW ports on the disk controllers (ones that were previously un-used), and leave controller ports that were in use un-connected, the warning will probably be too many wrong or missing disks, and you will need to use the "Devices" page to make the assignments to the correct slots in the array.

 

Joe L.

[WeeboTech]

Sometimes I really wish unRAID used the drive serial numbers so it did not care what port the drive was in.

Many times I'll connect a drive to the eSATA port.. then all the drives slide and it causes issues. 

[Joe L.]

Sometimes I really wish unRAID used the drive serial numbers so it did not care what port the drive was in.

Many times I'll connect a drive to the eSATA port.. then all the drives slide and it causes issues. 

I agree.

[fitbrit]

Why not just re-calculate parity?

Do an initial parity check, then rewire as your heart desires, then recreate the parity drive.

 

Sorry - I didn't meant to give the impression that I'm against calculating parity. I'm not at all, and would do so after a rearrangement. No, I was more curious as to how unRAID would respond and could I get it to start at all, without it wanting to reformat or clear drives? I just want to preserve the data and have no problem calculating parity.

 

 

Thanks for the answers guys.

[WeeboTech]

Take a snapshot of the drive layout as Joe suggests.

 

Be extra careful assigning parity to the correct media

If this is done incorrectly, you will end up erasing a filesystem.

Other then that, As long as you match drive for drive slot, there is no issue.

 

 

[fitbrit]

Take a snapshot of the drive layout as Joe suggests.

 

Be extra careful assigning parity to the correct media

If this is done incorrectly, you will end up erasing a filesystem.

Other then that, As long as you match drive for drive slot, there is no issue.

 

 

 

This is where I'm confused. I want to renumber the drives too, so that means changing drive slots. This is why I thought I might have to invoke the trust my array procedure to get things started... and THEN redo parity sync. Does what I'm saying make sense? I want to reorder the drives in my Centurion 590, and also renumber them, so that the current drive in slot 4, for example, ends up in slot 3 and is referred to from now on as disk3. If this is not possible, or ill-advised, I just won't change the slots around.

[Joe L.]

Take a snapshot of the drive layout as Joe suggests.

 

Be extra careful assigning parity to the correct media

If this is done incorrectly, you will end up erasing a filesystem.

Other then that, As long as you match drive for drive slot, there is no issue.

 

 

 

This is where I'm confused. I want to renumber the drives too, so that means changing drive slots. This is why I thought I might have to invoke the trust my array procedure to get things started... and THEN redo parity sync. Does what I'm saying make sense? I want to reorder the drives in my Centurion 590, and also renumber them, so that the current drive in slot 4, for example, ends up in slot 3 and is referred to from now on as disk3. If this is not possible, or ill-advised, I just won't change the slots around.

Just do as you described... Make sure the parity drive is assigned to the parity slot.  When you go to start the array it will warn you the drives are are different slots... Just check the checkbox under "Start" and start the array.

 

You can swap the data drive assignments exactly as you described.

[WeeboTech]

I understood what you wanted to do.  Reorder everything.

 

Personally, I would not do the trust my parity.

I would rebuild it when I had all the drives set up in the slots I wanted.

 

Actually I would turn off parity, order all the drives, make sure they mount where I wanted them too.

When all is good,  Add the parity and rebuild it.

 

If I've already checked my parity I'm confident the drives would be good.

The only issue is if you drop a drive or two.. (be careful  )

 

I plan to do the same thing as you just to make it easier to manage.

 

You can swap the data drive assignments exactly as you described.

 

You can also do this. I've never done it this way.

sometimes /dev/sda becomes /dev/sdd and I just reassign the drive and it's good.

But I've never done this procedure with more then one drive.

 

[fitbrit]

Thanks!

I think I'm confident enough to know when I'm about to lose data within unRAID, and can avoid those situations... unless it'll just start overwriting, which I doubt. I'll see if the array will start and take it from there. Eventually I want to replace my 750 GB drives with the 1 TB and 1.5TB drives I have, which of course means replacing the parity drive too. On another note, I still wish the Pro version would be stable with 20 data drives...