Can't boot after today's update

[Tyrannocaster]

System is LL 4.8. After updating today and then rebooting, the machine stuck in the spinning wheel phase. I finally got the Grub screen after messing with various options, but nothing I tried would let me boot so I restored the system using a 12 day old Clonezilla image, which, LUCKILY, worked.

But now I don't dare update the system again. What happened?

[Valtam]

The answer will be in the logs, which now no longer exist. If it happens again, check the boot etc logs.

[Tyrannocaster]

Okay. How do I read those, much less export them, when I don't have a functioning system? If you tell me where the file is, I can boot off a flash drive and find it, but I won't have an email account; I just tried setting one up while booted off a flash drive and Thunderbird wouldn't let me do it even though I had all the info needed for my account. I'm sorry I don't know my way around linux like everybody else here seems to; it's frustrating.

[Moltke]

Okay. How do I read those, much less export them, when I don't have a functioning system? If you tell me where the file is, I can boot off a flash drive and find it, but I won't have an email account; I just tried setting one up while booted off a flash drive and Thunderbird wouldn't let me do it even though I had all the info needed for my account. I'm sorry I don't know my way around linux like everybody else here seems to; it's frustrating.

Boot off a Live USB and check under /var/log, that's where the logs are kept. Also, make sure there's enough space left in the partition, a full or almost full partition will prevent the system from booting.