Guidance on SSD metadata sizing for NAS backups

[mark49808]

I see a few references that SSD is recommended for Metadata for NAS backup.

https://helpcenter.veeam.com/docs/backu ... ml?ver=110

"Most often, when performing restore, merge, transform operations, Veeam Backup & Replication interacts with metadata rather than with the backup data. Obviously, processing metadata stored on the SSD is faster and more efficient than accessing large data arrays stored on a slow storage."

My question is, I don't see any documentation around how to properly size this. Is there some rough estimate on MB of Metadata per TB of data (or per number of files?) or anything like that?

An example file share backup (NetApp) I have is about 1 million flies, 38k folders, and 1.5TB of data. I think I see 1.6GB of data in the "Meta" folder. So if i were to scale that up from 1.5TB to 1.5PB, should i assume that metadata will similarly scale up to ~1.6TB?

Thanks for any guidance or documentation you may have!

[Mildur]

Hi Mark

You have a sizing formula in the best practice Guide for VBR:
https://bp.veeam.com/vbr/2_Design_Struc ... srepo.html

[mark49808]

Oh wow, Metadata is 10%? "Metadata and free “workspace” need to be taken into account as well. Add 10% for each"

So for 1PB of backup data, we're talking 100TB of Metadata on SSD? That's a budget buster. At what point would SSD be "required"?

[Gostev]

At the point when you don't fit your backup window and need to improve your NAS backup performance.

[Dima P.]

Hello mark49808,

At what point would SSD be "required"?

The mentioned meta extent functionality was designed around slow storage devices or devices where there might be a delay in working with metadata (for example with deduplication storage metadata gets dehydrated and all regular backup / restore operations suffer noticeable performance impact every time we need to access it). Yes, you can definitely use it to bump up the current performance but it's optional. Regular repository with HDD will also work fine without the need to configure metadata extents.

So for 1PB of backup data, we're talking 100TB of Metadata on SSD?

The last minute estimate for the metadata size is 5% of your data size and that's a worst-case scenario (basically when your file share consists of huge amount of small files stored in complex directory structure).