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Dealing with different sizes of USB sticks

Posted: Mon Dec 11, 2017 4:26 am
by Michel
Hi Alex. Thanks for the tool. I am a new user and still looking at options. There are many forum items dealing with different USB stick sizes and it might be worthwhile having a "best practices" for this situation in your FAQ to provide a central reference. I have a bunch of USB sticks with Win 10 Recovery images and I want to save them as images in order to rebuild bootable sticks as needed to restore a trashed system as needed.

All the sticks are 32GB but are not identical. All the sticks have only about 10GB used. I am using EPM - EaseUS Partition Master (Free) to resize partitions - it seems to work well and preserves boot-ability.

Here's how I believe I should proceed. Please let me know if this seems to be a reasonable strategy in general. Do you see any problems or pitfalls?
1. Create recovery image using Win10 - it will fill the USB stick with a single partition.
2. Resize the partition using EPM down to 25GB to ensure any nominal 32GB stick will more than suffice.
3. Backup the shrunken partition to an img file using device mode.
4. Mount another 32GB stick.
5. Restore the img file with truncate option using device mode.

I assume that the truncation will only apply to blocks past the end of the valid partition space so the resulting stick will continue to be bootable and will have a completely valid and useable partition although the structure info may include an incorrect device capacity. Could this be a problem that would impede using the partition?

When the day comes that I want re-purpose the USB stick, I can use EPM to resize the partition to full size. Is there a way to resize everything back using USBImageTool? i.e. will "Reset" do that? I would also expect Win 10 Disk Mgr to be able to delete and rebuild a partition and correctly set the capacity info. Comments?

Thanks Alex.

Re: Dealing with different sizes of USB sticks

Posted: Thu Dec 14, 2017 9:22 pm
by Alex
Thanks for the feedback. The procdure will work and preserve user data on the flash drive, als long the size of the partition is smaller and the position before the truncated blocks. GPT based drives might undergo some automatic repair procedures, as I learned recently from another post.

Reset option will erase the whole device with zeros. As a consequence, Windows or any other operating system should be able repartition and reformat the device with its full size.

Re: Dealing with different sizes of USB sticks

Posted: Fri Dec 15, 2017 4:27 am
by Michel
Thank you Alex. Much appreciated.