Google Drive Switched From Mirror to Stream but the Old Mirrored Folder Is Still on Disk? Don’t Delete It Yet

Short answer: changing Google Drive for desktop from Mirror files to Stream files does not automatically remove the old local mirrored My Drive folder. Google explicitly says the old mirrored folder stops syncing, while the streamed My Drive moves to a virtual Drive location. That means you can temporarily have two visible copies of what looks like the same Drive: one new cloud-backed streamed view and one old full local folder that still occupies disk space.

The safe fix is not “delete whichever Google Drive folder looks old.” First confirm that every local change in the old mirrored folder finished uploading before the mode switch. Google’s current instructions specifically warn that unsynced files can be lost if you delete the old mirrored folder too early. Only after that verification should you quit Drive for desktop and remove the disconnected mirrored folder.

That distinction matters because this symptom looks like failed streaming when the real issue is often much simpler:

Stream mode changed the active Google Drive location, but it did not clean up your previous mirror for you.

First confirm that you are actually looking at two different storage paths

After a Mirror → Stream switch, Google documents a location change:

• Mirror files: My Drive is stored in a normal local folder on the computer.
• Stream files: My Drive appears through a virtual Drive location, and file content is mainly kept in the cloud unless accessed or marked available offline.

Google also says the previous mirrored My Drive folder no longer syncs after the switch.

So if Windows Explorer or Finder shows both:

1. a new Google Drive virtual location; and
2. an older normal folder containing a full copy of My Drive,

that is not automatically duplication inside your Google account. It can simply be one active streamed namespace plus one abandoned local mirror.

The practical test is simple:

1. Create a harmless test file in the new streamed My Drive.
2. Wait until Drive for desktop reports synchronization complete.
3. Confirm the file appears on drive.google.com.
4. Check the old mirrored folder.
5. If the old folder is truly disconnected, the new file should not appear there merely because you created it in the streamed location.

Do not use this test on an important file and do not delete anything during the test.

If the thing consuming disk is the streamed content cache rather than an old mirror, this is the wrong article. Use Google Drive Streaming Still Using Disk Space? instead. Stream mode still uses local cache for files you open, edit, use offline, or access frequently.

The dangerous part is not the old copy — it is unsynced local changes hidden inside it

A 500 GB abandoned mirror is annoying. A 500 GB mirror containing one project file that never reached Google Drive is dangerous.

Google’s current advanced Drive for desktop guidance explicitly warns that switching from Mirror to Stream is especially sensitive to unsynced changes. If you delete the old local folder before recent changes finish uploading, those unsynced files can be lost.

That creates three possible states:

The safest mental model is:

Old mirror ≠ cache.

A cache is disposable only when the application has safely committed the authoritative data elsewhere. A mirrored folder can contain ordinary user files, including files created locally moments before the mode change.

If you already have signs of unsynced or recovered local data, stop here and read Google Drive Lost & Found: Protect Unsynced Files Before Resetting Drive. A disk-cleanup task should not become a recovery incident.

Google’s current safe Mirror → Stream sequence is very specific

Google’s official help currently gives this order for switching from mirroring to streaming:

1. Open Drive for desktop.
2. Ensure local files have finished syncing to the cloud.
3. Open Settings → Preferences.
4. Under My Drive syncing options, select Stream files.
5. Close Drive for desktop.
6. Delete the old mirrored folder.

Google adds an important Windows-specific warning: quit Drive for desktop before removing the previously mirrored My Drive folder.

That sequence is more conservative than the advice you often see in forum threads because it separates three events:

sync completion → mode switch → local cleanup

Do not collapse them into one action.

Why Google does not delete the old mirror automatically

Google’s documentation does not need us to invent an internal implementation reason. The observable product behavior is enough: after the switch, the old mirrored folder stops participating in the active sync relationship, but Google leaves the files on the device.

That is a safer default than deleting local files automatically during a mode change because Google cannot assume every user wants the local copy destroyed immediately.

The downside is obvious: users switch to Stream specifically to save space and then wonder why the disk still looks full.

The answer is usually not “Stream failed.” The old mirror is simply still there.

How to prove the cloud copy is complete before deleting the old mirror

Do not rely on one green icon or the fact that the new streamed Drive opens correctly.

For important data, use several checks.

1. Check Drive for desktop sync status

Before cleanup, Drive for desktop should report that synchronization is complete rather than uploading, processing changes, or showing a sync error.

If it is stuck, do not delete the old mirror. Resolve the sync state first.

2. Compare the highest-risk folders on drive.google.com

You do not need to manually compare every file in a 4 TB library, but you should verify the folders most likely to contain recent local work:

• current project folders;
• files modified shortly before the mode switch;
• files created while offline;
• folders that previously showed sync errors;
• very large files that may still have been uploading;
• local-only exports or working files.

3. Check timestamps and file sizes for recent work

If project-final.psd is 8.2 GB in the old mirror and the cloud version is 7.9 GB with an earlier modified time, that is not a redundant copy yet.

Do not assume Google will reconcile it after you delete the local folder.

4. Preserve uncertainty instead of gambling

If you cannot prove a folder is fully represented in the cloud, move or copy that uncertain subset to a clearly labeled temporary safety folder outside Google Drive before deleting the old mirror.

That extra copy is not elegant. It is still cheaper than discovering two days later that an unsynced local version was the only usable version.

For large uploads, also remember that Google Workspace and Shared Drive environments can have separate transfer ceilings. If you were moving very large data sets, Google Drive’s 750 GB daily upload limit may be relevant to why a migration was not actually complete when you thought it was.

Why the old mirrored folder can look like a second Google Drive account

The visual confusion comes from location semantics.

When you used Mirror mode, the local folder was the active My Drive working copy.

After switching to Stream:

• the streamed My Drive is exposed in a virtual Drive location;
• the old local folder remains on disk;
• the old folder no longer follows new cloud changes;
• both can contain the same historical folder tree at the moment of the switch.

That creates an apparently duplicated library without necessarily creating duplicate cloud storage usage.

Imagine you had 900 GB mirrored locally.

Immediately after switching, you may see:

New virtual My Drive → represents the 900 GB cloud library, mostly without full local contents.

Old Google Drive folder → still contains the old 900 GB physical local copy.

The computer can therefore still use roughly the same amount of disk even though Stream mode itself is active.

Deleting the old local mirror after verification is what releases that large block of local storage.

This is different from cloud storage quota being full. The 900 GB local copy does not automatically mean your Google account is using an extra 900 GB in the cloud.

Stream mode still uses disk after the old mirror is gone

Do not expect local usage to drop to literal zero.

Google’s current Stream documentation says streamed files are primarily stored in the cloud, but local storage is still used when you work on files and for recently or frequently used content. Drive for desktop also maintains a local content cache.

So there are two separate sources of disk usage:

Layer 1 — the obsolete old mirror

Potentially hundreds of gigabytes or terabytes. This is a full normal local copy left from Mirror mode.

Layer 2 — the active Stream cache / offline files

Usually smaller and dynamic. It grows when you access files or mark items available offline.

Deleting Layer 1 does not remove Layer 2, nor should it.

If you clean the old mirror and disk usage later rises again as you work, diagnose the streamed cache separately using Google Drive Streaming Still Using Disk Space?.

That is why measuring disk space before the switch, immediately after the switch, and after deleting the old mirror gives you much better evidence than just saying “Google Drive still uses space.”

What if Drive starts uploading the old folder again?

This is where users can accidentally create a second synchronization relationship.

After switching My Drive to Stream, make sure the old mirrored folder was not separately added under Folders from your computer.

Google distinguishes:

• My Drive streaming/mirroring, and
• folders from your computer, which use their own computer-folder synchronization/backup relationship.

If you accidentally configure the old mirror as a computer folder, it may participate in a different upload path even though it is no longer the My Drive mirror.

Do not diagnose this from folder names alone. Check Drive for desktop Preferences and see what paths are actually configured.

This same distinction matters with removable storage. External-drive cloud sync, backup, and upload are separate workflows; a folder being visible to Drive for desktop does not mean it serves the same role as My Drive.

Switching in the other direction can deliberately keep both versions

The reverse migration — Stream → Mirror — has a different risk profile.

Google says that when you switch to Mirror:

• My Drive files download to the folder you select;
• if a file already exists locally and matches the cloud content, Drive tries not to duplicate it;
• if the local content differs from the cloud version, Drive keeps both;
• files not already present in the cloud are uploaded.

That “keep both if content differs” behavior is protective, but it can create apparent duplicates during a migration.

So if your issue started after Stream → Mirror, do not use the cleanup sequence in this article blindly. Your job is to identify whether Drive intentionally preserved conflicting local/cloud versions.

For missing-file incidents, Google Drive Lost & Found is the safer starting point because the priority becomes preserving every candidate copy before normalizing the folder tree.

A 2 a.m. cleanup checklist for Mirror → Stream

Use this exact order if the old mirror is still eating your SSD after you switched to Stream.

Step 1 — Confirm Stream is active

Open Drive for desktop → Preferences → Folders from Drive and confirm Stream files is selected for My Drive.

Step 2 — Identify the new virtual Drive location

Open the streamed My Drive and make sure ordinary cloud content is visible there.

Step 3 — Identify the old local mirrored folder

It should be a normal disk folder containing the previous full My Drive copy.

Step 4 — Do not edit both copies

Once the old folder is disconnected, continuing to work from it creates a dangerous split-brain workflow: you may edit files locally that no longer synchronize.

Move active work to the current streamed My Drive location or deliberately preserve the old folder as a separate local archive until verification is complete.

Step 5 — Verify recent local changes in the cloud

Check high-risk folders, recent files, large files, and anything created offline.

Step 6 — Preserve anything uncertain

Copy uncertain local-only material outside the Google Drive paths.

Step 7 — Wait for Drive for desktop to report synchronization complete

Do not treat “I can see the streamed Drive” as proof that yesterday’s mirrored edits reached the cloud.

Step 8 — Quit Drive for desktop

Google explicitly requires this before deleting the old mirror on Windows.

Step 9 — Remove the old mirrored folder

Only now is the large local copy treated as redundant.

Step 10 — Restart Drive and verify Stream mode still works

Open several ordinary cloud files. Confirm the old folder does not return as an active mirror and check that local free space increased.

Success looks like this:

• Drive for desktop is using Stream mode;
• the current My Drive is visible through the streamed location;
• current cloud files are intact;
• no unsynced local-only files were discarded;
• the old full mirrored folder is gone;
• local disk usage is now mainly the active Stream cache/offline working set rather than the entire My Drive library.

What not to do

Do not delete the old mirror immediately after flipping the switch

The mode setting changing successfully does not prove every pending local file already reached the cloud.

Do not keep editing the disconnected old folder

Once Mirror mode is off, that old path is no longer your live My Drive. Editing it can create local divergence that never reaches the streamed cloud location.

Do not clear the Stream cache to solve an old-mirror problem

The old mirror is a normal folder. Clearing an application cache attacks the wrong storage layer and can endanger unsynced Stream changes.

Google’s advanced documentation says unsynced Stream changes can live in the local cache until uploaded. Treat that cache as potentially important whenever Drive is not fully synchronized.

Do not assume two visible folder trees mean duplicate cloud billing

One may be the virtual streamed namespace and the other may be a disconnected local mirror. Confirm actual account storage separately.

Do not uninstall Drive for desktop just to free the mirror

Uninstalling changes much more state than necessary and does not prove that all local edits are safe in the cloud.

Why pCloud’s Drive/Sync split can be easier to reason about for archive-heavy users

Google Drive supports both Stream and Mirror, but they are two modes for My Drive. Switching modes changes where and how My Drive appears locally, and as this incident shows, the transition leaves the previous local mirror behind until you clean it up safely.

pCloud uses a different desktop mental model:

• pCloud Drive is the virtual cloud-first drive;
• Sync is a separate feature for folders you intentionally want mirrored locally.

That separation can make a storage architecture easier to reason about when you have:

• a multi-terabyte archive that should remain cloud-first;
• a much smaller set of active project folders that need permanent local copies;
• limited SSD space;
• frequent switching between cold archive and active work.

The structure can be:

pCloud Drive → remote archive

Sync → explicit active local folders

instead of repeatedly changing the storage mode of the entire main drive.

But CloudScope will not turn that into a fake absolute advantage. pCloud Drive still uses local cache during access and transfers, and pCloud’s own documentation says copy/paste uploads can require temporary disk space. If Google Docs, Workspace collaboration, or Google-native sharing is central to your work, migrating purely to avoid one Mirror→Stream cleanup may be irrational.

If the architectural separation is exactly what you have been trying to achieve, compare how pCloud Drive cache actually works before changing providers.

When you should stay with Google instead

Do not switch cloud providers because one cleanup step annoyed you.

Stay with Google Drive when:

• Google Docs / Sheets / Slides collaboration is central;
• Workspace sharing and permissions are already embedded in your team;
• Stream mode works well once the old mirror is removed;
• you need Google’s surrounding ecosystem more than a storage-first architecture;
• the old-mirror incident is a one-time migration cleanup rather than a recurring workflow conflict.

If your wider question is which service keeps the smallest local footprint across Dropbox, Google Drive, iCloud, OneDrive, and pCloud, use the Big 5 local-disk comparison. The answer changes depending on whether you need cloud-first archives, offline working sets, or OS-native integration.

The real decision is whether the old mirror is redundant or still authoritative

The dangerous mistake in this incident is treating file location as proof of file authority.

An old mirrored folder can be:

• a redundant full local copy that should be removed;
• the only place containing unsynced recent changes;
• a folder somebody is still editing even though it no longer syncs;
• a path accidentally re-added as a separate computer folder.

Only the first case is simple disk cleanup.

So before you delete 1 TB and celebrate the reclaimed SSD space, finish the missing decision:

Can you prove the old mirror contains nothing newer or more complete than the cloud copy?

If yes, close Drive for desktop and remove it. If no, preserve the uncertain files first.

That one verification is the difference between freeing disk space and manufacturing a data-loss incident.

Related reading

• Google Drive Streaming Still Using Disk Space? — use this after the old mirror is gone if Stream itself still consumes more SSD space than expected.
• Google Drive Lost & Found — use this before cleanup if any local changes are unsynced, missing, or uncertain.
• Cloud Backup vs Cloud Storage — a second local folder is not automatically a tested backup strategy.

More reading

• OneDrive Files Keep Downloading After Free Up Space — the Microsoft version of cloud-first content becoming local again.
• Dropbox Online-Only Files Keep Downloading — diagnose Dropbox rehydration rather than assuming a sync failure.
• iCloud Drive Files Download Again After Remove Download — the macOS/iCloud equivalent state-transition problem.

Reverse internal link suggestions

When this batch publishes, add contextual links to this article from:

1. /articles/google-drive-streaming-uses-disk-space/ — where Stream vs Mirror is introduced; link the mode-switch cleanup branch.
2. /articles/google-drive-lost-and-found/ — when warning users not to delete local Drive state before protecting unsynced changes.
3. /articles/cloud-storage-without-using-local-disk-space/ — inside the Google Drive Stream section as the migration cleanup guide.
4. /articles/cloud-storage-vs-external-hard-drive/ — where large local mirrored libraries are discussed.
5. /articles/pcloud-drive-cache-explained/ — as a contrast between mode switching and separate virtual-drive / Sync roles.

External sources

Checked on 21 August 2026:

1. Google Drive Help — Stream & mirror files with Drive for desktop: https://support.google.com/drive/answer/13401938
2. Google Drive Help — Customize Drive for desktop settings: https://support.google.com/drive/answer/13470231
3. Google Drive Help — Manage Google Drive for desktop: Advanced guide: https://support.google.com/drive/answer/16631477
4. pCloud Help — pCloud Drive vs (pCloud) Sync: https://help.pcloud.com/article/pcloud-drive-vs-pcloud-sync
5. pCloud Help — Low disk space warning in pCloud Drive: https://help.pcloud.com/article/low-disk-space-warning-in-pcloud-drive

Image metadata

1. Mirror → Stream hero

• Purpose: Show why switching modes can leave two visible copies on one computer.
• Filename: google-drive-mirror-to-stream-old-folder-hero.svg
• ALT: Google Drive mirror-to-stream migration showing the old local mirrored folder remaining beside the new virtual streamed Drive
• Caption: The streamed My Drive becomes the active cloud namespace, while the previous full local mirror can remain on disk until you remove it safely.
• Placement: After the introduction.
• Source: Original CloudScope technical diagram based on Google-documented Mirror/Stream behavior.
• Format: SVG source; optimize for web during batch build.
• Dimensions: 1200 × 630.

2. Safe cleanup sequence

• Purpose: Prevent deletion of unsynced local changes during the mode switch.
• Filename: google-drive-mirror-to-stream-safe-cleanup.svg
• ALT: Safe sequence for switching Google Drive from Mirror to Stream by verifying cloud sync before deleting the old local folder
• Caption: Mode switch is not the cleanup step. Verify cloud state first, then quit Drive for desktop and remove the disconnected mirror.
• Placement: Beside the official migration sequence.
• Source: Original CloudScope workflow diagram derived from current Google Drive Help instructions.
• Format: SVG source.
• Dimensions: 1200 × 760.

3. Google vs pCloud architecture

• Purpose: Compare Google My Drive mode switching with pCloud's separate Drive/Sync roles without claiming zero local caching.
• Filename: google-drive-stream-vs-pcloud-drive-sync.svg
• ALT: Architecture comparison of Google My Drive switching between Mirror and Stream versus pCloud Drive and Sync as separate roles
• Caption: Google changes My Drive between two local-storage modes; pCloud exposes virtual-drive storage and explicit mirrored Sync as separate jobs.
• Placement: In the pCloud architecture section.
• Source: Original CloudScope conceptual diagram using documented Google and pCloud product behavior.
• Format: SVG source.
• Dimensions: 1200 × 760.

Internal link map

1. Google Drive Streaming Still Using Disk Space? → /articles/google-drive-streaming-uses-disk-space/ → introduction → Horizontal
2. Google Drive Lost & Found → /articles/google-drive-lost-and-found/ → data-loss warning → Horizontal
3. Google Drive 750 GB daily upload limit → /articles/google-drive-750gb-upload-limit/ → cloud-verification section → Horizontal
4. What happens when cloud storage is full → /articles/cloud-storage-full-what-happens/ → duplicate-storage clarification → Horizontal
5. External-drive cloud workflows → /articles/sync-external-hard-drive-cloud-storage/ → accidental second relationship section → Horizontal
6. pCloud Drive cache explained → /articles/pcloud-drive-cache-explained/ → architecture comparison → Down
7. Big 5 local-disk comparison → /articles/cloud-storage-without-using-local-disk-space/ → stay-with-Google section → Up
8. Cloud Backup vs Cloud Storage → /articles/backup-vs-cloud-storage/ → Related reading → Up
9. OneDrive files keep downloading → /articles/onedrive-files-keep-downloading-after-free-up-space/ → More reading → Horizontal
10. Dropbox online-only files keep downloading → /articles/dropbox-online-only-files-download-again/ → More reading → Horizontal
11. iCloud files download again → /articles/icloud-drive-files-download-again-after-remove-download/ → More reading → Horizontal

CTA

• Position: After the Google-vs-pCloud architecture explanation.
• Copy: Check whether pCloud's storage model fits the split →
• Destination: https://partner.pcloud.com/r/156919
• Plan Match: Plans & Pricing / General
• Rel: sponsored noopener

Structured data and social metadata

• Structured data: Article + BreadcrumbList
• Canonical: https://cloudscope.org/articles/google-drive-old-mirrored-folder-after-switch-to-stream/
• OG title: Google Drive Mirror → Stream: Delete the Old Mirror Safely
• OG description: Switching to Stream does not remove your old Google Drive mirror. Verify every local change is in the cloud before deleting the disconnected folder.
• OG image: /assets/google-drive-mirror-to-stream-old-folder-hero.svg