list of learning management systems

setting Process: Rule zeroing: Clears all existing rules (Iptables-f ...), at least stop-off service Default policy: Except INPUT This custom chain is set to DROP, the other is the default ACCEPT; Trust native: Lo must be set as a trust device because Lo is very important to the machine; Response packet: A packet that responds to a native unsolicited request can go to the native (established,related) Trust users: This is not necessary if you want to make the source of t

process with the most delay; Kill command: Sends a control signal to the process for process management Show current system available signals:# kill-l# Man 7 signal Common signals:1) SIGHUP: No need to close the process and let it reread the configuration file;2) SIGINT: Abort the running process, equivalent to CTRL + C;9) SIGKILL: Kill the running process;SIGTERM: terminates a running process;Sigcont):SIGSTOP): How to specify the signal:(1

Chkconfig command to manage the power-on startup items, but set the run level when setting the boot entry, and the default 2,3,4,5 level if you do not specify a levelChkconfig--list #查看所有服务的运行级别信息Chkconfig--list snmpd #查看snmpd服务所有的运行级别信息[Email protected] ~]$ chkconfig--list snmpdSNMPD 0:off 1:off 2:off 3:off 4:off 5:off 6:off[[email protected] study]# chkconfig-

, example: * * * * command, that is, 12 points per day per month to execute commands Second, the closure and start of serviceNtsysvChkconfig--list Chkconfig--level 2 ATD off/on Chkconfig ATD on Chkconfig--add to add a script Third, the system log/etc/rsyslog.conf /var/log/messages /var/log/secure /var/log/maillog To view sent messages: Cat/var/log/maillog/var/log/cron /var/log/spooler /var/log/boo

CPU informationCat/proc/cpuinfo, compared with the former , more detailed(5) The uptime command displays the start time and average load of the system, which is the first line of top, and the W command can also see this data. (6) View system and kernel-related informationuname [Options]Where the-a option means viewing all relevant information about the system; the-r option means viewing the kernel version;-s option means view kernel nameDetermine the number of bits of the current system:file [S

常关闭指定vm650) this.width=650; "src=" Https://s4.51cto.com/wyfs02/M00/91/40/wKioL1j0w3byHQJNAAAzHo2YNoo260.png "title=" Screenshot from 2017-04-17 12-06-32.png "alt=" Wkiol1j0w3byhqjnaaazho2ynoo260.png "/>Virsh Destroy Vmname # #强行结束指定vmVirsh Create Vmname.xml # #临时恢复指定vm, Vmname represents the front-end management fileVirsh Define Vmname.xml # #永久恢复vmVirsh undefine vmname # #删除vm前端管理, storage not deleted650) this.width=650; "src=" Https://s2.51cto.com/w

|--checksig} package FILE650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M01/5E/2B/wKiom1UpS-CTKlNVAAFnwE1gr3Q034.jpg "title=" 8.jpg " alt= "Wkiom1ups-ctklnvaafnwe1gr3q034.jpg"/>--nosignnature: Does not check the legitimacy of the source --nodigest: Do not check integrityRPM Manager database:/var/lib/rpm (each program installed, the installation information will be stored in this directory)Rebuild the database:--INITDB: Initialize the database, that is, the database does not exist at all,

"current user" resides~account represents the user's home directory (account is a name)The variable that executes the file path $pathSee what directories are defined? Echo $PATHLS Viewing files and directories-A All files include hidden files-l List Detailed properties Ls-l = llLs-al list the properties of all files in the directory including hidden filesCP Copy CopyCP Source File Destination file-I if the

scope, such as the local variable in the Func function when the F function finishes executing (global variable does not) (4) The container where the object is located is destroyed, or the object is deleted from the container 6. Indicate:Function call variable A,a reference count +2 because there is one more step to the argument.7. GC Module1 #referencing Lib files2 ImportGc#GC module File is_enable () =true does not start garbage collection automatically3 ImportSYS4 5Gc.set_debug (GC. DEBUG_

: net.ipv4.ip_forward=1Sysctl-p Restart the service. So that the value after this is 1 when viewed################################################All network management-related commands can be found in the file/usr/share/doc/initscripts-x.x.xx this fileConfiguration of the 4.DHCP service1. On the real machine, after resetting the two virtual machines, set the NIC IP for the DHCP server host servers and restart the network service for it to take effect

values , and the normal user can only adjust their nece value and adjust the range to 0--19. To prevent nice from being a negative value when the resource is preempted, and the nice value can only be adjusted higher and lower than the nice values , the PRI and NI have some relevance:PRI (new) =pri (old) +niIt is important to note that, from a relational standpoint, although NI can affect the priority of the process, the priority of the process is ultimately determined by the core of the system

://blog.51cto.com/schenjiannan/1258183Four FDISK disk partitionsFdisk is a very powerful disk management tool that usesfdisk -l 设备名称Do not specify a device name to list all disk devices and partition tables in the systemIf specified.For example, a new HDD SDB执行 fdisk /dev/sdbWill prompt you to enter m to get partition helpYou just have to read d delete a partition n create a new partition P print partition

The core of the Linux security system is the user account, and Linux has strict control over each account's permissions. Each user has a UID (ID is unique). The following is the first to learn about the user account configuration file: (1)/etc/passwd file: Root:x:0:0:root:/root:/bin/bash daemon:x:1:1:daemon:/usr/sbin:/bin/sh bin:x:2:2:bin:/bin:/bin/sh Sys:x:3:3:sys:/dev:/bin/sh Sync:x:4:65534:sync:/bin:/bin/sync games:x:5:60:games:/usr/games:/bin/sh man:x:6:12:man:/var/cache/man:/bin/sh lp:x:7:

-Y if Yum needs a user response during work. This parameter can answer yes directly#yum list lists all the RPM packages that can be installed or updatable in the repository#yum Perl-listed packages for Perl#yum perl* list the packages that begin with PerlInstalling Perl packages #yum Install Perl#yum Remove perl* Delete all perl-* packages#yum check-update Check for RPM packages that can be updatedUpdating

Classification of services:Linux Services: RPM package Default installed services, source package installation ServicesTo view the self-starting status of a service:Chkconfig--list #查看服务的自启动 (only see RPM package installed Services)Source package installed in the specified location, is generally/usr/local/; RPM package installed in default location; (Usr=unix system Resource)Services and Ports:/etc/services #端口与服务的对应文件NETSTAT-LTUNP #查询系统中开启的服务RPM Inst

General Instructions for debugging information Info Basic notification Information Notice General information, but it is of some importance Warning Warning message, but does not affect the operation of the service or system Err Error messages, which generally reach the err level can affect the operation of the service or system Crit Critical condition information, more severe than err

The DB2 tutorial being looked at is: DB2 UDB V8.1 Management Learning Notes (iii). Force disconnect an existing connection, stop the instance, and delete. $ db2idrop-f instance_name Used to migrate instances under UNIX. $ DB2IMIGR instance_name Update the instance to get access to some new product options or revision packages. $ DB2IUPDT instance_name Gets the instance that is currently in place. $ DB2 Get

not need to enter the passwordThe content format of the password file/etc/rsyncd.passwd is: Username:password, the permission is The command to start the service is: Rsync–daemonDefault to use/etc/rsyncd.conf This configuration file, you can also specify the configuration file rsync--daemon--config=/etc/rsyncd2.confThe available options are: Rsync–daemon--help rsync ip::test:/directory 1/directory 2: Synchronizing data using the test moduleRsync-av--password-file=filename/Directory/directory:

,g=rx,o=rx[[email protected] ~]# mkdir/tmp/test[[email protected] ~]# ls-ld/tmp/tes Tdrwxr-xr-x. 2 root root 4096 January 8 00:32/tmp/test[[email protected] ~]#when creating a new file, the default is no execute permission for security purposes . For example, create a new Test1.txt file under the TMP directory with the following default permissions:[Email protected] ~]# touch/tmp/test1.txt[[email protected] ~]# ls-l/tmp/test1.txt-rw-r--r--. 1 root root 0 January 8 00:34/tmp/test1.txt[[email

$chown command.Stat (PATH)View additional information for the file pointed to by path, equivalent to the $ls-l command.symlink (SRC, DST)Create a soft link for the file DST, SRC is the path to the soft link file. Equivalent to the $ln-s command.GETCWD ()Query the current working path (CWD, working directory), equivalent to the $PWD command.2 Shutil Bagcopy (src, DST)Copy files from Src to DST. Equivalent to the $CP command.Move (SRC, DST)Move files from Src to DST. Equivalent to the $MV command