I cloned my SSD to my USB using dd, but the USB won't boot...Here's the story: I just got a 275 GB SSD to replace my 128 GB SSD, which is running low on space, but I want to continue using my Ubuntu 16.04 OS exactly as I have set it up.  Based on tutorials I've read, the method to do this seems to be:Copy the 128 GB SSD to to the 256 GB USB.Install the 275 GB SSD.Boot from the 256 GB USBCopy the 256 GB USB to the 275 GB SSDSo, I cloned my SSD (128 GB) to my USB (256 GB) using the following command learned from here:sudo dd if=/dev/sda | sudo dd of=/dev/sdb bs=32M status=progressThe process completed a few hours later without error.  Before installing the new 275 SSD, I decided to test the USB and see if it would load.  So, I restarted my computer, went into BIOS to change the primary boot device to the USB, restarted again.  The computer seems to have skipped booting from the USB, because it booted from the SSD.When the 128 GB SSD loaded, I entered sudo fdisk -l, which output the following:Disk /dev/sda: 119.2 GiB, 128035676160 bytes, 250069680 sectorsUnits: sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisklabel type: gptDisk identifier: 77422302-BE7A-49CA-ABA7-DAF209D9121ADevice         Start       End   Sectors   Size Type  /dev/sda1         34   1050815   1050782 513.1M EFI System    /dev/sda2    1050816 241919956 240869141 114.9G Linux filesystem/dev/sda3  241919957 250069630   8149674   3.9G Linux swapGPT PMBR size mismatch (250069679 != 483471359) will be corrected by w(rite).Disk /dev/sdb: 230.6 GiB, 247537336320 bytes, 483471360 sectorsUnits: sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisklabel type: gptDisk identifier: 77422302-BE7A-49CA-ABA7-DAF209D9121AAccording to the emboldened portion, there is a GPT PMBR size mismatch that can be corrected by w(rite).  In several other postings related to cloning using dd, I did not notice anyone who was giving direction state that the GPT PMBR size mismatch might occur.  Most often, the caution was to make sure the drive being cloned to is larger than the drive being cloned from.Anyway, I read the fdisk man page and there's no w(rite) or w or rite, so I don't know what the emboldened portion is telling me to do.So, I searched the internet and followed the instructions on this page, using gdisk, which did not seem to do anything because fdisk -l continues to show GPT PMBR size mismatchSo, I searched the internet and found this page, which describes a similar situation, and I followed the instructions therein by entering the following:sudo dd if=/dev/sda of=/tmp/mbrsda.bak bs=446 count=1sudo dd if=/tmp/mbrsda.bak of=/dev/sdb bs=446 count=1Then I rebooted and, still, the USB won't boot.How do I get my USB to boot so I can dd it to my 275 GB SSD?I am a novice with Linux, but I want to understand how it works, so I think solving this using dd is better for my understanding than if use CloneZilla.
DD Clone not booting
backup;dd;cloning