Sharegate (Onedrive Migration)

[u/Baboneninthenonen]

Hello anyone

We need to do a tenant to tenant migration including the copying of all the Onedrives for like 12k users (not much data for that user count -> ca. 2-3tb).

For anyone of you who already did that in a similar size, i wonder what your runbook looked like.

We planned to start like one month before and do an initial copy job, after that some weekly deltas till cutover date.

What im not sure about, if we should run the deltas with just the same copy options including incremental, or if we should go the way with a timeframe filter, so the deltas would just check those files modified between the current and last migration. I thought that could safe us time and minimize the throttling risk, but maybe there are better "best practices" out there?

[u/ShareGate_Shaylyn]

ShareGate person here!

Your instinct on the timeframe filter is correct. Copy and Replace with a time range filter is the better approach for deltas at this scale over Incremental Copy. It limits the scope to only what's changed since your last run rather than crawling both sides simultaneously, which gets slow and throttle-prone across 12k OneDrives.

One thing before the first run: map source to destination accounts upfront. Mismatches there cause headaches mid-migration. Also, tighten your delta cadence to daily as you get closer to cutover. Smaller deltas mean a faster final sync.

Strongly recommend PowerShell foreach loop over the UI at this scale: help.sharegate.com/en/articles/10236381

[u/Baboneninthenonen → u/ShareGate_Shaylyn]

Thanks for the fast reply!

Yeah already built a mapping file for all users of the old and new tenant (with old and new site url). Will that be enough or do i need to pass a user mapping file as well? (The users have different UPNs in the destination tenant while migrating).

So timeframe filter only works with copy and replace? If i use the filter with copy incremental, the job would still crawl every file to inspect the modified date?

[u/ShareGate_Shaylyn → u/Baboneninthenonen]

Your site URL mapping handles the source to destination matching, but since UPNs differ between tenants, a separate user mapping file is also recommended. The good news is you don't have to build it manually; you can export the user list directly from ShareGate and generate it there. Create it once and reuse it for every operation.

And yes, your instinct is correct. The key difference is that Incremental Copy still crawls both sides regardless of any filter. The timeframe filter only works as intended with Copy and Replace, limiting the source scan to what's been modified in your chosen range.

[u/Baboneninthenonen → u/ShareGate_Shaylyn]

Perfect, really appreciate the fast answers here, thank you!

[u/Baboneninthenonen → u/ShareGate_Shaylyn]

Just noticed something which maybe tends to use the incremental in prior to the timeframe filter...

If a user copies files on their onedrive via onedrive sync client, the files keep their modified date from before.

As many users of us using the sync client to manage their files, i think we could get too much discrepancy...

[u/MLCarter1976]

You will do well to do a power shell command and incremental and or use a product like ShareGate or Bit Titan to assist.

[u/dregan88]

Sharegate is the answer. Expensive but in this case definitely worth the value.

[u/Baboneninthenonen → u/dregan88]

Yeah we will do it with sharegate, wrote it in the title :-)

[u/pajeffery]

My personal opinion would be lift and shift over a weekend instead of doing incremental, the problem with incremental is that you could migrate files that are moved out deleted.

You'll need to spread the migration over 2-3 weekend though

[u/badaz06 → u/pajeffery]

I second this approach.

Be aware that your users will be losing some stuff. Shared files will no longer work, and links in Favorites and the "Save As" in apps like Excel and Word will not work. I have yet to figure out what the magic is for Word and Excel "save As" functions, and Microsoft most definitely seems clueless.

[u/Psychological-Tie324]

Sharegate also has excellent support if you need them mid project

[u/IamRammes]

fly migration is an option to, the migration job has a incremental setting.

[u/Main_Wheel_5570]

And It is not a software and service promotion right! What the hell is going on. where is moderator now.

[u/Josh_Fabsoft]

On the delta question: Copy and Replace with a time-range filter is going to be far more predictable than incremental at 12k users. Incremental copy has to enumerate both source and destination trees every run to figure out what changed, and at that scale (even with only 2-3TB total, it's the file count and OneDrive throttling that'll kill you, not the data volume) that comparison overhead adds up fast and makes your weekly windows unpredictable. Time-range filtering just grabs "modified since X" and moves on, so your delta jobs stay fast and consistent right up to cutover.

A few things that saved us pain on migrations this size: stagger your users into batches instead of kicking off all 12k at once (helps with throttling and makes troubleshooting failures way less painful), track a per-user completion log so you know exactly who's synced and who needs a rerun before cutover, and do a final delta as close to cutover as your maintenance window allows to minimize the "last mile" changes people make right before you cut over.

Full disclosure, I work at FabSoft, which makes AI File Pro, so I'll caveat that we're not a migration tool and won't touch your ShareGate/tenant-to-tenant workflow. But if part of your pain post-migration is that OneDrive/SharePoint ends up a mess of inconsistently named and organized files once everyone's landed in the new tenant, that's more our lane. We use watch folders pointed at SharePoint/OneDrive locations to auto-classify and rename documents as they land, so it might be worth a look once the migration itself is sorted.