I created a startup USB drive with Startup Disk Creator from 18.04.1 image and successfully used it to install Ubuntu. Then I decided to inspect it with GPT fdisk, and
gdisk reported "invalid main GPT header" and other issues:
§ sudo gdisk /dev/sdc [sudo] password for alexey: GPT fdisk (gdisk) version 1.0.3 Caution: invalid main GPT header, but valid backup; regenerating main header from backup! Caution! After loading partitions, the CRC doesn't check out! Warning! Main partition table CRC mismatch! Loaded backup partition table instead of main partition table! Warning! One or more CRCs don't match. You should repair the disk! Partition table scan: MBR: MBR only BSD: not present APM: not present GPT: damaged Found valid MBR and corrupt GPT. Which do you want to use? (Using the GPT MAY permit recovery of GPT data.) 1 - MBR 2 - GPT 3 - Create blank GPT Your answer: ^C
Is this expected? Is this a bug in "Startup Disk Creator" or something else? Is it safe to install Ubuntu from a drive where "CRCs don't match"?