I'm about to take on a migration involving several large SharePoint Online sites, some with document libraries running into hundreds of thousands of files, and I'm trying to figure out the most efficient way to approach this without the whole thing dragging on for weeks.

The obvious challenge with scale is throttling. Microsoft's API limits kick in hard once you're moving large volumes of data, and I've learned the hard way that pushing too aggressively just triggers longer wait times overall. Building in realistic time estimates based on actual throughput, rather than best-case assumptions, has made a huge difference in setting expectations with stakeholders.

Breaking the migration into logical batches rather than attempting everything in one massive run also helps a lot. It makes it easier to isolate errors, retry failed items without re-running the entire migration, and keep momentum without long periods where nothing seems to be progressing.

Incremental/delta migrations have been useful too, especially when content is still actively being used during the transition. Doing an initial bulk transfer followed by delta syncs closer to cutover reduces the amount of downtime users actually notice.

For efficiency at this scale, manual PowerShell scripting alone hasn't cut it for me. I've had much better results using the DRS Softech Tenant-to-Tenant Migration Tool, which handles batching, incremental syncs, and error retries more efficiently, along with clear progress tracking across large libraries.

What's worked best for you when dealing with large-scale SharePoint migrations?

Outlook nagging for a password it won't accept is one of those problems that seems minor until it locks you out of an archive you actually need. It usually comes down to a PST file that's password-protected from years back, sometimes by an employee who's no longer around, sometimes just a forgotten credential nobody wrote down. The instinct is to start guessing passwords or poking around in Outlook's settings, but repeated failed attempts and clumsy workarounds carry a real risk of corrupting the file, which turns a locked archive into an unreadable one.

A safer fix is a dedicated DRS Softech PST Password Remover Tool built specifically to handle this without touching the underlying data. Rather than trying to guess or crack anything, a tool like this strips the existing password directly and restores full access, working in a read-only mode so the emails, folders, and attachments inside stay exactly as they were. It also runs entirely offline, which matters when you're dealing with sensitive business archives you don't want touching any external server, and it can process several locked PST files in one pass if you're clearing out password issues across an entire department rather than a single mailbox. Some versions even let you set a new password across multiple files at once, which is handy if you're trying to standardize access policy after sorting out the immediate problem.

Google Photos is great until you realize your storage is packed with duplicate shots, you know, the same sunset captured five times, or a dozen near-identical selfies before you got "the one." When you finally decide to download and back up your library, hauling all those duplicates along is a waste of both time and disk space. The smart move is to clean things up before you export, not after. Sort your albums, use built-in tools or a dedicated photo cleanup app to spot duplicates, then batch-select the accidental repeats before saving anything to your local drive. Google Photos itself has been improving its bulk-download options, but it still won't automatically filter out duplicates for you, so a bit of manual sorting is worth the upfront effort. If you want a clear step-by-step walkthrough on getting all your photos out of Google Photos efficiently, this guide on how to download all photos from Google Photos covers the process well. A little prep now saves you from re-downloading a bloated, duplicate-heavy archive later.

When converting PST files to PDF, one of the biggest mistakes people make is treating it as a simple format change and ignoring what happens to the metadata along the way. Sender and recipient details, timestamps, CC/BCC fields, subject lines, and even read/unread status all matter — especially if the converted PDFs are going to be used for legal documentation, compliance records, or long-term archiving. Lose that metadata, and you're left with a PDF that looks like an email but can't actually be verified as one.

The problem usually comes from using basic methods like printing emails to PDF manually or copy-pasting content into a document. These approaches capture the visible text but strip away the underlying header information and structure that gives an email its authenticity. For anything beyond casual note-taking, that's a real risk — particularly if the PDFs might ever need to hold up as evidence or pass an audit.

The safer approach is using a converter specifically designed to retain email metadata during the conversion process. The DRS Softech PST to PDF Converter handles this well, converting PST files to PDF in bulk while preserving headers, timestamps, sender-recipient details, and attachments exactly as they appear in the original email. This makes the converted files reliable for archiving, legal use, or sharing with anyone who needs accurate, complete records.