Shulou(Shulou.com)06/02 Report--

Learn the general content today.

Yum

-scheduled tasks:

-one-time execution: at batch

-Periodic execution: crontab

-manage temporary files for the system

Summary of the yum command:

Yum install xxx [Software name]-y

Yum command

Yum install softwarename # # installation

Repolist # # list setting Yum source information

Remove softwarename # # Uninstall

List softwarename # # check whether there is secondary software in the software source

L ist all # # list all software names

List installd # # list the names of installed software

List available # # lists the names of software that can be installed with yum

Clean all # # clear yum cache

Search softwareinfo # # search for software names based on software information

Whatprovides filename # # find the software package containing the filename file in the YumSource

Update # # Update Software

History # # View the history of system software changes

Reinstall softwarename # # reinstall

Info softwarename # # View software information

Groups list # # View software group information

Groups info softwaregroup # # View the software contained in the software group

Groups install softwaregroup # # install components

Groups remove softwaregroup # # Uninstall components

[the above is all knowledge]

Assignment 1 searches for software related to raid

2 find out what the function of vsftpd is

3 list all package names provided in yum

4 list what passwd files are provided

5 find out the software package with pam by using the function of yum

6 find the software package related to java and install version 1.7

Permanent mount

1 mount the device first

2 enter mount to copy and mount the latest record

3 Open configuration file / etc/fstab to modify content

4 mount-a detection

5init6

At and batch

At command

Scheduled tasks, work tasks that are performed only once

# after the at task is submitted, save it in the file in the / var/spool/at/ directory

The atd service monitors the files in the / var/spool/at/ directory and executes them if the time is up.

At

-l # is equivalent to the atq command, listing scheduled tasks

-m # if the scheduled task has no output,-m can be notified by email.

-d # is equivalent to the atrm command, which deletes a scheduled task, followed by a number

-v # specifies scheduled tasks in an easy-to-read time format; at-v now+1day

-c # specific contents of scheduled tasks

Time format of at: (accurate to minutes only)

HH:MM HH:MM YYYY-MM-DD

HH:MM [am | pm]

HH:MM+5min

Now+5day [| min | month | day]

At's black and white list

/ etc/at.allow has high priority

/ etc/at.deny has low priority

Batch command:

1. Results of batch when the test load is small

Uptime batch echo 'hello' mail

1. When the test load is more than 0.8, the result of batch; 1). Increase load load; dd if=/dev/zero of=file bs=10M

Count=1000 2). Uptime 3). Batch

Crontab

Crontab's black and white list

/ etc/cron.deny (system exists by default)

/ etc/cron.allow

Rule: if / etc/cron.allow, only the user in the file can execute crontab

If / etc/cron.allow is empty, only root users can execute crontab

Cron.allow is always a priority; crontab files (crond service management)

User-level periodic tasks: crontab-e-u user

Periodic tasks at the system level: / etc/crontab / etc/cron.d / etc/cron. {monthly,weekly,daily,hourly}

Crontab format

Minutes, hours, days, months and weeks command

* / 10 9-17 1 commands 15 * *

# several special symbols:

*: per cent, every month, every week

/ n: after every other n

-: 1-2, 3-10, from x to y

,: or

Crontab command

Crontab-e # editing, saving to / var/spool/cron/

Crontab-e-u user # Edit user

Crontab-l # list

Crontab-r # deletion

# 3. Management of system temporary files #

# the service in the system will generate temporary files when it is running normally

/ usr/lib/tmpfiles.d/*.conf # # configuration of temporary files in the system

File type file name file permissions file owner file all group file existence time

D / mnt/westos 777 root root 10s

Systemd-tmpfiles-create / usr/lib/tmpfiles.d/* # # perform temporary file configuration

Systemd-tmpfiles-clean / usr/lib/tmpfiles.d/* # # temporary files in Qingli

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