user admin

#sg                    ---- change group
#gpasswd groupname     ----create group passwd in /etc/gshadow

#useradd [option] username
default in /etc/default/useradd  without option
#useradd -d /opt/oracle  -g dba oracle
1.edit /etc/
2. create and populatiing home directroy from /etc/skel/
3. setting permissions and ownership

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in shell create passwd automatically
# echo" oracle" | passwd --stdin oracle
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#usermod -u 50000 oracle    --change uid
#usermod -a -G fuser oracle  --append a new group fuser to user oracle
#usermod -g alex oracle  --change user oracle's primary group to alex
#usermod -L oracle    ---lock user
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#userdel  -r alex   ---delete user and his home directory
# modify default expiration settings in /etc/login.defs

#vi /etc/login.defs   --user passwd"  expired date)
#chage user
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# vi /etc/fstab    ---
/dev/glsvg/GLShome    /home    ext3  defaults, usrquota,grpquota    1 2

#mount -o remount usrquota,grpquota  /home
 or
#mount -a  --- to remount from /etc/fstab
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#quotacheck -cugm /home  ---quota is base on /dev/sda not base on directory, it can use to limit inodes and block. most of time we limit block
no inode.  warning when reach soft limit
#quotaon, quotaoff --- start and stop quotas
#edquota  username
or shell   setquota username 4096 2049 10 20
#touch abe{29..43}  --create file abe29-abe43

#quota the default block size is k