Does NTFS performance degrade significantly in volumes larger than five or six TB?

One of my customers is planning to set up a new document store, which will probably grow by 1-2TB per year. One of my co-workers says that Windows performance is extremely bad if it has a single NTFS volume that is bigger than five or six TB. He thinks that we need to set up their system with multiple volumes so that no single volume will exceed that limit.

Is this a real problem? Does Windows or NTFS slow down when the volume size reaches several terabytes? Or is it possible to create a single volume of 10 or more TB?

Solution 1:

I've made 30TB volumes before. They were holding large files, so that greatly assists in avoiding performance degradation. No problems there versus smaller volumes.

Where problems might begin to occur is if that large filesystem builds up enough files and directories to get to the insanely big ranges. I'm talking 20 million files and directories or more levels. At that point the MFT is likely to be pretty fragmented and on RAM constrained servers that might start to introduce some directory-display performance issues. Actual access to files should not be affected, just fileOpen() and directory scanning operations.

Is it a real possibility? Yes, but the effect also holds true for similarly large filesystems on other platforms and for the same reason. Also, the operations most impacted by the performance drop may not even be the ones you're worried about. Since this sounds like a new setup, it doesn't sound like you'll be using this 10TB on a server with only 1GB of RAM so you shouldn't have to worry.

Where the worry about size came from is likely WinNT and Win2K era, when MBR limitations made large volumes tricky to create. Such needed some trickery to address all of that, and in the era the trickery had a cost. This magnified the lots of little files performance penalty. GPT doesn't have this problem. GPT volumes were first in Windows 2003, but their newness meant conservative sysadmins didn't use them much at first.

Old attitudes die hard, sometimes. Especially if there is trauma reinforcing them.

Solution 2:

We have some much bigger than that (using W2K8) and we've not seen any noticable performance drop offs.