Backing up 3TB of photos from one external drive to a 2nd external

Don’t worry, the drive probably won’t fail during the long backup, especially if you’ve been using it recently and it’s been fine. Over the years, tens of thousands of creative pros have routinely backed up or migrated many TB of photo and video files to newer, bigger, faster drives and newer computers every few years. This routine chore is something a normal hard drive is built to handle easily. Remember, the same kind of hard drive runs all day long inside millions of PCs, and 24/7 in data centers around the world, under all kinds of loads.

Look for software that can automate backups and copies. You didn’t say whether you’re using a Windows PC or an Apple Mac; I’m on a Mac so some very reliable software for this is Carbon Copy Cloner, SuperDuper!, and ChronoSync but others work well too. With any of those applications, you can set a source drive and destination drive, tell it to copy everything, and then tell it to update the copy to exactly match the source. They also let you save that as a preset for future periodic backup updates. Just open the preset and tell it to update the backup. If you have multiple drives to back up, you can make a preset for each of them so that they can update different backups in just a few clicks. These applications also let you verify your backups to help detect corrupted files.

There are similar applications for Windows PCs, but I’m not familiar with them.

After several tries, I  settled on Goodsync and am very pleased.

I work with several 5TB USB drives.

A complete copy can be broken down into multiple small tasks.

Once you have a complete copy it is quick and easy to keep the master and slave copies in synch on a daily basis.

I have lived on the road in a motorhome for 14 years so far so maintaining backup copies is very important to me. I have an Odd Day Backup Drive, an Even Day Backup Drive, an Odd Month and Even Month Drive, and maintain drives at 3 siblings residences when ever passing their towns. The drives backup the entire working Drive of my complete computer.

You don’t tell us why you think the drive will fail. Please explain.

It’s not clear to me if this is really a backup (making an exact duplicate of everything so you now have two copies of these files that will both be kept). It doesn’t sound like a backup to me as you are likely to stop using the original drive, and then you only have one copy of the files, in which case an actual backup MUST be made as well (this is, in my opinion, mandatory) to another as yet unmentioned drive, so you will have two exact duplicates of the files.

If you are worried about putting stress on the drive, you could move the photos in bunches, and pausing for a while between bunches. I have never heard this advice for hard drives, and I don’t know if it is really valid.

I would use GoodSync to backup your images.  There are many YT videos on this, here is one… 

for you catalog, use Lightroom to periodically backup you catalog.