Zend certified PHP/Magento developer

Every HDD suddnely read-only

After booting KDE Neon, suddenly all of my HDDs are read-only. One of them is removable, and that one had an error when I ran fdisk -l: gpt pmbr size mismatch will be corrected by write.

I plugged that disk into another machine and it appears to be OK, so what’s going on with my disks?