Today is my first class on RHCE. When I saw the strength of RHCA, I suddenly learned how to use it. Exceeding my predecessors is my goal! Summarize the course content. In the morning, it was the first chapter of the article mentioned by Miss Su. In the afternoon, Miss Wu spoke about some content: What is the difference between FTP and TFTP? ftp uses the TCP transmission protocol, which is reliable but inefficient, applicable to wide area networks. Tftp is a simple ftp. It uses UDP protocol, which has poor reliability but high efficiency and is suitable for LAN. The most basic Linux is initrd. img. Today is my first class on RHCE. Seeing the strength of RHCA, I suddenly learned how to use it. Exceeding my predecessors is my goal!
Summarize the course content.
In the morning, it was the first chapter of the article said by Miss Su. In the afternoon, Miss Wu spoke about some content:
- Differences between FTP and TFTP
Ftp uses the TCP transmission protocol, which is reliable but inefficient and suitable for wide area networks.
Tftp is a simple ftp. It uses UDP protocol, which has poor reliability but high efficiency and is suitable for LAN.
- The most basic Linux is initrd. img + vmlinuz.
Linux = OS ==> kernel = initrd. img + vmlinuz
Moreover, initrd is built to ensure the stability of the system kernel. It is an independent driver that does not load too many things into the kernel. Vmlinuz is the main kernel of Linux, including common drivers.
He can do a lot of exaggerated things, such as random disconnection and connection to a hard disk, top-level optimization system, but it is disgusting to learn.
- The instructor rejects CDROM.
I feel that a teacher can use an MBA. He doesn't like CDROM. Everything is done through the network or local hard disk, he said that the command to use Live CD to guide local installation is in boot: Enter linux askmethod later and I will study it again. After all, I am a newbie.
First Boot is a place where the teacher thinks the RedHat design is unreasonable. It only appears when the image is installed, and the name "First Boot" is used only at the First installation. Therefore, when learning to optimize the system, we need to disable it from the service.
Kdump is the Kernel Dump. The instructor deleted this item from the beginning because it seems useless. In fact, this is a very useful thing that can be used to exclude kernel errors and run it after the Kernel is dead, but how awesome it would be to load a trojan in this way! ~ This is something that will be used in the future.
- Streamline system services
For simple optimization, you can set System services in the setup command.
The following services are generally removed:
Atd -- automation task controller. Since crond is available, the old one is removed.
Bluetooth-bluetooth, none of my computers. It is necessary to turn it off.
Ip6tables -- ipv6 support. I don't have it, so disable it.
Isdn-almost no one uses the Internet access method.
Rhnsd-Use The rhnsd server to keep RedHat up to date. Of course I don't have the money to buy this, so I don't need to find it. Turn it off
Sendmail -- use sendmail to send emails. I use web pages to send emails. Do not use sendmail. disable it.
Yum -- RHEL used for update learning. I should do the update manually. I accidentally overwrite the previously modified content and disable it.
- How does the system know that your partition is a bootable partition?
The "0x55aa" Marking System on the last two digits of the first sector of the bootable partition knows that this is bootable.
