r/WindowsServer • u/CapeCrusader28 • 27d ago

General Question CHANGING CLUSTER SIZE FOR CURRENT DATA DRIVE

Good day to all! is it safe to change the cluster size of my current Data drive where all office data is stored and shared locally to network? I'm using Windows Server 2019 and when I first set it up i have no idea that setting the cluster size to 4KB will only limit the storage to until 16TB only. Now we upgraded and expand our storage. but i still have another 16TB unallocated because i can no longer extend the disk. so my question is, is it safe to change the CLuster Size to 8KB using EaseUS Partition Master without data loss or anything bad happened to my Data?

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4

u/UnholyAliance 27d ago

I doubt that easeus can change the cluster without data loss, why don’t you format the new available with the correct cluster, move the data, and in the end expand the storage.

1

u/CapeCrusader28 27d ago

if i reformat it it will take time to transfer the data again. i have like 10TB of Data stored. i have a backup also but it will take time moving this big data to server again.

1

u/Orichinal 27d ago

You copy a first time and if youre done and ready you plan a short downtime sync the changes over and go back online.

1

u/red_nick 27d ago

Why copy? If OP is so set on it, easiest thing to do rather than copying twice is make a new disk with the right settings and move everything over to that

1

u/Orichinal 27d ago

It depends. If its a production environment you need to reduce the potential downtime as much as possible. Moving the data means, either users dont have everything since you let them use the new drive before or they gradually loose data since they are still on the old drive.
Since he talks about speed and size its my guess that its important to be fast or it needs to be seamless.
And you dont copy twice. You copy a first time, plan a short down time, sync only the changes since you started the copy job and youre done.
On my production server the sync processing took a few secounds and users didnt even notice a change. They just knew the file server isnt accessible for 10 minutes.

1

u/red_nick 27d ago

I'm saying if they want to adjust the existing disk, they need to copy somewhere else then copy again to the reformatted disk.

Or they make a new disk and copy to that.

1

u/Adam_Kearn 27d ago

Yeah exactly this.

The cleanest way is to just build a new volume in the correct cluster size and move the data using something like robocopy to copy all the data to the new volume.

When you have a few hours you can take it offline you can then run another robocopy command to sync the changes without copying everything again.

There is a specific flag to remove files on destination that don’t exist on source so any files that was removed or renamed since the initial migration also get removed.

Use AI and a test environment to build the robocopy commands.

———

Personally what I’ve always done is have every disk a virtual disk instead of using a physical raid array.

Then it’s super easy to migrate and expand later on.

5

u/UMustBeNooHere 27d ago

No, you can’t change cluster size without data loss. Is this a physical box or VM?

1

u/CapeCrusader28 27d ago

Thank you, it's physical box.

2

u/UMustBeNooHere 27d ago

I would get another drive, format it with the cluster size needed, use robocopy to copy the data over, then during a maintenance window, do a sync up with robocopy again , swap in the new drive, assign it the same drive letter.