Cloning two hard drives into one can be done, but it requires some planning and preparation. The main considerations are whether the target drive has enough storage capacity, and how to merge the data from the two source drives.
Quick Answer
Yes, you can clone two hard drives into one, provided the target drive has sufficient storage capacity to hold all the data from both source drives. You’ll need disk cloning software to copy the contents of the source drives over to the target drive.
How Much Capacity Is Needed?
The first step is to determine if the target drive has enough storage capacity to hold the contents of both source drives. Add up the used space on each source drive – not the total drive size, just the amount of data currently stored on each.
For example, if drive A contains 250GB of data, and drive B contains 300GB of data, you’ll need a target drive with at least 550GB of free space to fit both drive images.
It’s a good idea to add some extra buffer space, say an extra 10-20% capacity. So in the above example, you may want to use a 650GB or 700GB target drive to give yourself some room.
What Kind of Target Drive Should I Use?
You can use any blank hard drive as the target drive, as long as it meets the minimum capacity requirements outlined above. Here are some options:
- External USB hard drive
- Internal SATA hard drive
- Solid state drive (SSD)
An external drive is handy for cloning as you can connect it temporarily via USB, clone the source drives over, then disconnect when done. Internal SATA drives will require installation in a desktop computer or drive enclosure/dock.
SSDs are much faster than traditional hard drives, so make an ideal target drive for optimal performance. Just be sure to choose an SSD with sufficient capacity – they typically come in 120GB to 4TB sizes.
How to Combine the Contents of Two Drives
Once you have a suitable blank target drive, you need disk cloning software to copy the contents of the two source drives over to the new drive.
Most third party cloning tools can handle this type of dual drive clone. Examples include:
- Macrium Reflect (Windows)
- Clonezilla (Windows/Linux)
- Carbon Copy Cloner (Mac)
- Acronis True Image
- AOMEI Backupper
The process involves:
- Connect both source drives and the target drive to the computer.
- Run the cloning software.
- Select the two source drives and choose the target drive as the destination.
- The software will then copy all data from both sources over to the target drive.
- After cloning completes, shut down and disconnect the old source drives.
The target drive now contains a merged image of both source drives. You may need to extend or resize partitions on the target drive to utilize all available space if the source drive sizes were different.
Things to Keep in Mind Before Cloning
Here are some important considerations before combining two drive images onto a single target:
- Make sure no OS files or boot partitions are duplicated. Having two boot partitions can cause issues.
- Delete duplicated applications and data on the second source drive before cloning.
- Temporarily disable or disconnect other non-target drives to avoid accidental data loss.
- Verify the source/target drive connection cables and ports are properly seated.
- Use a fresh, blank target drive – do not clone onto a drive with existing data.
- Backup important data as a precaution before cloning.
Possible Challenges When Cloning Two Drives
Cloning two drives into one does pose some potential challenges:
- Insufficient storage space – The target drive must have enough capacity to hold all data from both source drives. Adding an exact 1:1 clone of two large drives may overfill the target drive.
- Duplicate OS/boot partitions – Having two operating system or boot partitions from different source drives can create boot issues. The cloning software may need to delete or merge these partitions.
- Drive alignment problems – If the source drives had different sector alignments, the cloned images may not align properly on the target drive. This mainly affects older rotational drives.
- Permission and access errors – If the same files and folders exist on both source drives, the cloning process may have trouble dealing with two sets of permissions and access rules.
- Hardware malfunctions – Physical drive failures can interrupt or corrupt the cloning process. Always verify the health of all drives first.
Frequently Asked Questions
Is it better to clone to an internal or external drive?
An external drive is usually more convenient for cloning as you can easily connect it via USB just for the cloning process. But an internal drive will give better performance in the long run for daily use after cloning is complete.
Will cloning delete everything on my target drive?
Yes, the target drive will be completely overwritten by the cloning process. So make sure it does not contain any data you want to keep.
Should I clone the whole drive or just used space?
Most cloning software allows you to choose. For simplicity, cloning the full contents of both source drives is fine. But for efficiency, you can select to only clone the partition structures and used space – unused space does not need to be copied.
Can I expand the partitions after cloning two drives?
Yes, if your cloning tool does not automatically resize partitions to fill the target drive, you can use Windows Disk Management or third-party partition tools after cloning to expand the partitions to utilize all available space.
What happens if the target drive runs out of space mid-clone?
The cloning operation will fail. This highlights the importance of ensuring your target drive has sufficient capacity before beginning the clone process. Have at least 10-20% free space buffer beyond the combined used space of your source drives.
Step-by-Step Guide
Follow these steps to successfully clone two hard drives into one:
- Install cloning software – Such as Macrium Reflect, Clonezilla, Acronis True Image, etc. on your computer.
- Connect all drives – Attach the two source hard drives and the target drive to your computer.
- Verify drive health – Check all drives for errors using built-in disk utilities.
- Launch cloning app – Run the disk cloning application you installed.
- Select source & target – Choose the two source drives and the blank target drive.
- Resize partitions – Extend partitions on the target drive to use all available space.
- Verify clone – Boot from the target drive to test that the cloned data is accessible.
Take things slowly, validate the cloning outcome at each step, and keep backups of your source drives as an added precaution.
Cloning vs. Manual Data Consolidation
Disk cloning streamlines the process of combining two drives into one, but there are also manual methods you can use:
Cloning Benefits
- Faster and easier than manual migration
- Exact replicas of source drives
- All data and OS moved automatically
Manual Migration Benefits
- Allows selectively moving only needed data
- Avoids duplicates and removes unneeded files
- More control over file locations and folder structures
Cloning is quicker, but manual migration gives you a chance to clean up your data and only transfer over what you really need from both source drives.
Cautions When Deleting Old Source Drives
Once the cloning operation completes successfully, you’ll want to retire the old source hard drives.
It’s very important though to first boot from the target drive alone and verify you can access the cloned data. Don’t quickly delete the old source drives before validating the integrity of the clone.
Once you confirm everything copied over properly and the system boots fine from the new drive, you can format the old source drives or safely dispose of them.
If anything seems corrupted or lost on the new drive, you’ll want the source drives intact to troubleshoot where the cloning process went wrong.
Alternatives to Cloning for Merging Drives
While drive cloning is the quickest way to combine two drives, here are a couple alternative approaches:
Clean OS Install on New Drive
- Install fresh OS copy on new large drive
- Manually migrate data over from both old drives
- Gives you a clean slate but takes more work
Attach as Secondary Drives
- Add old drives to new system as extra storage
- Gradually transfer files manually as needed
- Allows accessing old data when needed
These methods take more effort but provide alternatives to directly cloning if you want more control over the migration process.
Conclusion
Cloning two hard drives into one larger drive can be accomplished by using disk cloning software to copy the contents of both source drives over to a sufficiently large target drive.
The process requires careful planning to avoid issues like insufficient target capacity, boot conflicts, and data duplication. But when done properly, drive cloning provides an efficient way to merge two drives into one without having to manually move and consolidate all your data.