linux sysadmin course

"pxelinux.0";Next-server 172.25.254.100;}[Email protected] tftpboot]# Vim/var/lib/tftpboot/pxelinux.cfg/default-------------------------------------------------- 61 label Custom # #增加选项 "Custom" 62 menu label ^custom Install # #选项名称为 "Custom Install "," ^ "indicates the following character Fugauliang 63 kernel vmlinuz 64 append initrd=initrd.img repo=http://172.25.50.250/rhel7.2 Quiet # #quiet表示不看内核信息 65 66 label Linux 67 Menu Label ^instal

contents of the scheduled task on the editor and save the Exit3. Use Crontab-l to view the list4.cat/var/log/cron/the user to see if the content was compiled successfully0 1 * * 7 oracle/backup.shKernel:1 briefly describe the functionality of the kernel.1. Pass the application request to the hardware2. Can be a separate kernel module2 How can I permanently modify the kernel parameters without rebooting the system?1. Use the SYSCTL command to display all available values2. Edit with the VI comma

key: Ctrl+rFunction: Automatically searches the command cache for subsequent characters that are entered.Shortcut keys: TabFunction: Command line auto-completeShortcut key: Ctrl+kFunction: Clears the character from the location of the prompt to the end of the line. 4. Simple differences between single quotes, double quotes, and unquoted in a Linux shell Single quotation marks: the contents of single quotation marks are outpu

20125101 Song YumengAfter a semester of semester, Linux this course finally ended. The teacher broke the teaching method of the former course, mainly by the form of self-study and classroom test to ensure the progress of our study. At first, I didn't get used to the rhythm, because lazy didn't keep up.The teacher's progress, so there are a few tests have a very l

The Riyuerusuo, the good, I am again sentimental. But the days are really too fast, Linux has to be a lesson, I also want to become a senior dog. Digress, pull back, say this semester Linux bring me bitterness bitter spicy, hundred taste mixed (actually also not so hard).The first choice of this course is that Lou teacher really is the big God, feel that follow L

Linux OPS Practice-September 5, 2015 Course Assignment (practice) ScheduleTask Schedulerperform a task at a time in the future at batchperform a task periodically crontabEmail Servicesmtp:simple Mail Transfer Protocol Simple Mail Transfer ProtocolPop3:post Office Protocal 3 Post Office Protocol version 3imap4:internet Mail Access Protocol Interactive Data messaging protocolMailmail-s ' SUBJECT ' [email prot

root, bin or hadoop under the/usr directory;12. Find all files whose contents have been modified and are not root or Hadoop for the last week in/etc directory;13. Find all files on the current system that are not owned by the master or group, and have been visited in the last week;14. Find all files that are larger than 20k and type ordinary files in/etc directory;15, look for all the users in/etc directory do not have permission to write files;16. Find at least one class of users who do not ha

the first part of the name and the hyphen that follows it completely. Can be populatedMore parts of the name have been matched. For example: Type get-c and then type the TAB key to automatically replenish the Get-childitem command, and if you continue to press the TAB key, the command that is added is get-comMand command.One thing to note when using the command line auto-completion is that whenever the tan key is interpreted as an auto-replenish command feature, you need to be aware that when c

Course Summary of Linux20125133 Ma Guoxiangthrough 16 weeks of learning to learn that Linux is not an overnight thing, must be able to persist in using it, especially in the early days, because in Linux, user rights are very large, do anything is very free, so you often need to know what you do every step of what, the system did something, It takes time to master

example:[[email protected] var]# ls-d/var/l*[0-9]*[[:lower:]]/var/l12d/var/l1c/var/l3b/var/l3k/var/labc8dfdse7. Displays files or directories that start with any number in the/ etc directory and end with a non-numeric number. Ls-d/etc/[0-9]*[^0-9]8, show /etc directory, start with a non-letter, followed by a letter and any other arbitrary length of any character file or directory. Ls-d/etc/[^[:alpha:]][[:alpha:]]*or ls-d/etc/[^a-z][a-z]*.9.in the/ tmp directory, create a file that starts with T

CP command to save the/etc/directory for archiving, storage location is/backups/etc-yyyy-mm-dd;[Email protected] ~]# mkdir/backups[Email protected] ~]# CRONTAB-E* * 1-6/bin/tar-czvf/backups/etc.$ (date +%y-%m-%d) tar.gz/etc/650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M02/72/CE/wKiom1XtZ5vxm_IHAABP_rACL_Q488.jpg "/>Third, every Sunday 2:30 A.M., run the CP command to backup the/etc/fstab file, the storage location is/backup/fstab-yyyy-mm-dd-hh-mm-ss;[Email protected] ~]# crontab E* *

* Digital rights: R (Read): 4,w (Write): 2,x (Execute): 1Example: chmod 755/tmp/test (File permissions modified to: Rwxr-xr-x)650) this.width=650; "src=" Http://www.51testing.com/attachments/2017/04/14982672_201704201036261NrVL.jpg "border= "0" style= "margin:0px auto;padding:0px;border:0px;" alt= "14982672_201704201036261nrvl.jpg"/>* Delete this file only if you have write access to the directory where the file is locatedOperation ExampleTouch A.txtchmod u+w A.txt provides write permission to t

Bootproto=static|none # #网卡工作模式Onboot=yes # #网络服务开启时自动激活Name=eth0 # #网络接口名称IPADDR=172.25.0.100 # #IP地址netmask=255.255.255.0 | PREFIX=24 # #子网掩码: WqSystemctl Restart NetworkIf you want to set multiple IPs on the network card (as if it can set up to 99), can not use netmask, only with prefix"Setup" command # #红帽6及以前的版本可以使用 "Setup" command to configure IP, Red Hat 7 is not####################[Email protected] desktop]# systemctl Restart Network # #重启网络基本服务[Email protected] desktop]# systemctl resta

LinuxSmall Brackets()and curly braces{}is the execution of one of these commands, but there is a certain difference, and its specific meaning is as follows:(): Commands within parentheses are executed in a child shell (()): Compare and calculate the values in parentheses$ (): command substitution, equivalent to anti-quote '$ (()): integer Arithmetic{}: Manipulating a set of characters within parentheses${}: reference to Variable[]: Condition test[[]]: Conditional test to support regular expressi

will be transferred to go to execute subroutine code, in order to be able to accurately return when the subroutine executes, need to push the address of the next instruction of the call instruction into the stack. Then create a new stack for the subroutine, the assembly instructions are as follows: PUSHL%EBP MOVL%esp,%EBP The PUSHL%ebp instruction pushes the base address of the stack of the keynote program into the stack, and ESP,EBP all points to the next bit of the start of

First step: Find all files in the/oldboy directory and its subdirectories that end with the extension. shFind all Files:[Email protected] oldboy]# find/oldboy/-type f/oldboy/t.sh/oldboy/test.sh/oldboy/test/del.sh/oldboy/alex.txt/ Oldboy/oldboy.txtFind all files ending with. sh[Email protected] oldboy]# find/oldboy/-type f-name "*.sh"/oldboy/t.sh/oldboy/test.sh/oldboy/test/del.sh13.2 Step Two: How to replace the Oldboy in a file with the Oldgirl[[email protected] oldboy]# #sed ' s# What you're l

I was in a junior high when I was with Linux. I was familiar with Linux when I stumbled across "Linux should learn". Because I am an electronic information engineering major, in the senior year opened the embedded curriculum, embedded system is a special computer system, as part of the device or equipment. All devices with digital interfaces, such as VCRs, cars,

1, review the contents of this course;Linux Disk ManagementHard disk: Hard disk is the common term, in fact, hard disk and disk are the same, are used to store things, as well as tapes, CDs, u disk and so on just storage media is not the same.Mechanical hard-diskSSD Solid State DriveMechanical type:Track tracksPer sector (sector): 512bytesMagnetic column (CYLINDER): The basic unit of the partition;Master bo

Linux Course notes (operating system Basics)-20160822Layer Fourth: Application (1, run through kernel call,2, call library run)The third layer:library:API(Application programming Interface) libraries can only be executed when other programs call, the execution environment is calledSecond Floor: Kernerl: Kernel Management hardware ResourcesFirst layer: HardwareFeatures of the kernel:1. Process Management2. M

) Perform the installation as DSO (BIN/APACHECTL-M see if it is installed) Just copy the following configuration to the end of http.conf to save all virtual hosts Deflatecompressionlevel 9 #压缩的等级, the greater the compression level, the higher the CPU consumptionSetoutputfilter DEFLATE #启用压缩Addoutputfilterbytype DEFLATE text/html text/plain text/xml #这三行设置压缩类型Addoutputfilterbytype DEFLATE Application/javascriptAddoutputfilterbytype DEFLATE Text/cssAlso available as a Curl