Pass the RedHat RHCE EX300 Questions and answers with CertsForce

According to question, log server is already configured. We have to configure the mail, web and dns server for log redirection. In mail, web and dns server:

vi /etc/syslog.conf mail.* @logserveraddress

service syslog restart

mail is the facility and * means the priority. It sends logs of mail services into log server.

1. groupadd sysusers groupadd command is used to create the group and all group information is stored in /etc/group file.

When user creates the file/directory, user owner will be user itself and group owner will be the primary group of the user.

There is one Special Permission SGID, when you set the SGID bit on directory. When users create the file/directory automatically owner group will be same as a parent.

1. chmod g+s /data

2. Verify using: ls -ld /data

You will get: drwxrws---

chgrp sysusers /storage

Verify using ls -ld /storage command.

You should get like drwxr-x--- 2 root sysusers 4096 Mar 16 17:59 /storage chgrp command is used to change the group ownership of particular files or directory.

Another way you can use the chown command.

chown root:sysusers /storage

chmod g+s /storage

Verify using: ls -ld /stora

Note:

Permission should be like:

drwxrws--- 2 root sysusers 4096 Mar 16 18:08 /storage If SGID bit is set on directory then who every users creates the files on directory group owner automatically the owner of parent directory.

To set the SGID bit: chmod g+s directory

To Remove the SGID bit: chmod g-s directory

Login as a root user

cat >schedule.txt

30 05 * * * /bin/echo "Hello"

crontab -u jeff schedule.txt

service crond restart

The cron system is essentially a smart alarm clock. When the alarm sounds, Linux runs the commands of your choice automatically. You can set the alarm clock to run at all sorts of regular time intervals. Alternatively, the system allows you to run the command of your choice once, at a specified time in the future.

Red Hat configured the cron daemon, crond. By default, it checks a series of directories for jobs to run, every minute of every hour of every day. The crond checks the /var/spool/cron directory for jobs by user. It also checks for scheduled jobs for the computer under /etc/crontab and in the /etc/cron.d directory.

Here is the format of a line in crontab. Each of these columns is explained in more detail:

#minute, hour, day of month, month, day of week, command

* * * * * command

Entries in a crontab Command Line

Field Value

Minute 0-59

Hour Based on a 24-hour clock; for example, 23 = 11 p.m.

Day of month 1-31

Month 1-12, or jan, feb, mar, etc.

Day of week 0-7; where 0 and 7 are both Sunday; or sun, mon, tue, etc.

Command: The command you want to run

1. vi /var/schedule

30 17 * * * /sbin/dump -0u /dev/st0 /dev/hda7

2. crontab /var/schedule

3. service crond restart

We can add the cron schedule either by specifying the scripts path on /etc/crontab file or by creating on text file on crontab pattern.

cron helps to schedule on recurring events. Pattern of cron is: Minute Hour Day of Month Month

Day of Week Commands

0-59 0-23 1-31 1-12 0-7 where 0 and 7 mean Sunday.

Note * means every. To execute the command on every two minutes */2.

After reboot and verify with this command