由于工作需要，相信不少人的电脑是装的windows+ubuntu双系统。当windows系统出现问题需要重装的时候，需要格式化C盘，ubuntu的引导就会被删除，导致不能进入ubuntu系统。网上试了一些办法，总结下来分享给大家～

Somehow cupsd using 100% CPU, creating large (80GB+) error_log in /var/log/cups/. Deleting the log-files could solve the problem permanently, a new error_log files would be created by progress cupsd again and its size kept increasing, and full of the space finally.

Generally, we need to keep multiple versions of gcc/g++ to fit our compiling environment. This blog can teach you how to switch your system gcc/g++ version in ubuntu system.