1. Change the HOSTNAME line in /etc/sysconfig/network
2. Change the hostname (FQDN and alias) in /etc/hosts
3. Run /bin/hostname new_hostname for the hostname change to take effect immediately.
4. Run /sbin/service syslog restart for syslog to log using the new hostname.
A reboot is not required to change the system hostname.
How to enable SSH in Linux: -
#chkconfig -list sshd
#chkconfig –level 345 sshd on
How to enable mouse in Linux: -
#vi /etc/X11/xorg.conf
Section “device” (add the below line)
Option “HWCursor” “off”
#gdm restart
How to make a iso image: -
#mkisofs -o /tmp/file_name.iso /u01/software_contents_folder_name
1. for firewall enable/disable:-
chkconfig iptables off
chkconfig ip6tables off
Or
system-config-securitylevel
2. to network services:-
service network restart
service network start
service network stop
or
/etc/init.d/network start
/etc/init.d/network restart
/etc/init.d/network stop
3. nmap localhost: - it will display the port details, which are all opened for this Box.
4. nautilus – it’ll work in putty. It will display all the windows in the Linux server.
1.rsync –a / root@
How to create a symbolic link in Linux: - $ ln –s target_filename symlink_filename
xstart
gdmstart
Tar:-
1. To tar the one or more files:-
$ tar –cvzf <.tar.gz file name with path>
To un-tar the .tar.gz file:-
$ gunzip <.tar.gz file name>
$ tar –xvf <.tar file name>
How to increase the swap space in Linux:-
1.First check free space in file system.
$df -h
2.And find out the free space in one file system, and create swap space in that file system.
$dd if=/dev/zero of=/
3.Change the permission :- $ chmod 600 swapfile
4. Setup the swap file with the command : - $ mkswap swapfile
5. To enable the swap file immediately but not automatically at boot time: -
$ swapon swapfile_name
6.To enable it at boot time, edit /etc/fstab to include: -
/swap_file_location swap swap defaults 0 0
(When time the system boots, it will enable the new swap file.)
7. After adding the new swap file and enabling it, make sure it is enabled by viewing the output of the command cat /proc/swaps or free.
How to change the partition name in Linux:-
1.First create a required directory under the / partition:-
$mkdir /oracle
2.Edit the /etc/fstab file:-
Old entre: - LABEL=/ora /ora ext3 defaults 1 2
New entre: - LABEL=/ora /oracle ext3 defaults 1 2
3.Then unmount the old partition & mount the new partition:-
$umount /ora
$mount /oracle
$rm –rf /ora (deleting the old partition)
4.To check the progress:-
$df –h
Use free space to create logical volume on LVM partition:-
[root@igloo ~]# vgdisplay
--- Volume group ---
VG Name VolGroup00
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 5
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 1
Act PV 1
VG Size 74.41 GB
PE Size 32.00 MB
Total PE 2381
Alloc PE / Size 193 / 6.03 GB
Free PE / Size 2188 / 68.38 GB
VG UUID JoY5DH-S0HV-Q5Dw-b2wC-Rpe0-XeaR-QFbG75
[root@igloo ~]# lvscan
ACTIVE '/dev/VolGroup00/LogVol00' [5.03 GB] inherit
ACTIVE '/dev/VolGroup00/LogVol01' [1.00 GB] inherit
[root@igloo ~]# lvcreate -l 2188 VolGroup00 -n LogVol02
Logical volume "LogVol02" created
[root@igloo ~]# lvscan
ACTIVE '/dev/VolGroup00/LogVol00' [5.03 GB] inherit
ACTIVE '/dev/VolGroup00/LogVol01' [1.00 GB] inherit
ACTIVE '/dev/VolGroup00/LogVol02' [68.38 GB] inherit
[root@igloo ~]# mkfs -t ext3 /dev/VolGroup00/LogVol02
mke2fs 1.36 (05-Feb-2005)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
8962048 inodes, 17924096 blocks
896204 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=20971520
547 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 21 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@igloo ~]# e2label /dev/VolGroup00/LogVol02 /oracle
[root@igloo ~]# cat /etc/fstab
# This file is edited by fstab-sync - see 'man fstab-sync' for details
/dev/VolGroup00/LogVol00 / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
LABEL=/realvar /realvar ext3 defaults 1 2
none /dev/pts devpts gid=5,mode=620 0 0
none /dev/shm tmpfs defaults 0 0
none /proc proc defaults 0 0
none /sys sysfs defaults 0 0
/dev/VolGroup00/LogVol01 swap swap defaults 0 0
/dev/VolGroup00/LogVol02 /oracle ext3 defaults 1 2
/dev/hdc /media/cdrom auto pamconsole,exec,noauto,managed 0 0
/dev/fd0 /media/floppy auto pamconsole,exec,noauto,managed 0 0
Create the partition name with required name in / and mount it:-
[root@igloo ~]#mkdir /oracle
[root@igloo ~]#mount /oracle
Check with the df –h command.
Run Level’s in Linux:-
Run Level
Generic
Fedora Core
Slackware
Debian
0
Halt
Halt
Halt
Halt
1
Single-user mode
Single-user mode
Single-user mode
Single-user mode
2
Basic multi-user mode (without networking)
User definable (Unused)
User definable - configured the same as runlevel 3
Multi-user mode
3
Full (text based) multi-user mode
Multi-user mode
Multi-user mode - default Slackware runlevel
4
Not used
Not used
X11 with KDM/GDM/XDM (session managers)
Multi-user mode
5
Full (GUI based) multi-user mode
Full multi-user mode (with an X-based login screen) - default runlevel
User definable - configured the same as runlevel 3
Multi-user mode
6
Reboot
Reboot
Reboot
Reboot
The script below will display all files that are greaten then one megabyte in size. Note that the size parameter is specified in K-bytes.
root> find . -size +1024 –print
./prodsid_ora_22951.trc
Of course, you can easily append the xargs of –exec command to automatically remove the large file:
root> find . -size +1024 –print|xargs –i rm \;
This find command will do a "stats" on all files in a directory structure, showing the total size of all files in the directory. You can also incorporate the "df -k" command"
find ${START_DIR} -mtime -${DAYS} |xargs stat -c "%s"|awk '{sum += $1}END{print sum}'
select sid, serial# from v$session s, dba_datapump_sessions d where s.saddr = d.saddr;
select sid, serial#, sofar, totalwork from v$session_longops;
rman> list backup;
rman> list backup of database;
rman> list backup summary;
rman> list incarnation;
rman> list backup by file;
rman> list copy of database archivelog all;
rman> list copy of datafile 1, 2, 3;
rman> list backup of datafile 11 summary;
rman> list backup of archivelog from sequence 1234;
rman> list controlfilecopy "/u01/app/oracle/ctrl1.cpy";
rman> list backupset of datafile 1;
select
session_key, db_name,
min(r.start_time) start_rman,
min(c.checkpoint_time) start_controlfile,
min(d.checkpoint_time) start_datafile,
min(a.first_time) start_archivelog,
max(a.next_time) end_archivelog,
min(b.start_time) start_set,
max(b.completion_time)
end_set, min(p.start_time)
start_piece, max(p.completion_time) end_piece
from
rman.rc_backup_controlfile_details c
join
rman.rc_backup_datafile_details d
on c.session_key = d.session_key
join
rman.rc_backup_archivelog_details a
on c.session_key = a.session_key
join
rman.rc_backup_set_details b
on c.session_key = b.session_key
join
rman.rc_backup_piece_details p
on c.session_key = p.session_key
join
rman.rc_rman_backup_job_details r
on c.session_key = r.session_key
where
db_key =
(select db_key
from rman.rc_database
where name = 'alice1')
and
c.checkpoint_time >sysdate-14
and
d.checkpoint_time >sysdate-14
and
r.start_time >sysdate-14
and
a.first_time >sysdate-14
and
b.start_time >sysdate-14
and
p.start_time >sysdate-14
and
a.next_time >sysdate-14
and
b.completion_time >sysdate-14
and
p.completion_time >sysdate-14
group by
session_key,
db_name;
Cleanup trace files more than 7 days old: -
root> find $DBA/$ORACLE_SID/bdump/*.trc -mtime +7 -exec rm {} \;
root> find $DBA/$ORACLE_SID/udump/*.trc -mtime +7 -exec rm {} \;
root> find $DBA/$ORACLE_SID/cdump/*.trc -mtime +7 -exec rm {} \;
Cleanup redo log files that are more than 7 days old: -
root> find $DBA/$ORACLE_SID/arch/*.log -mtime +7 -exec rm {} \;
You can query v$session and join into v$sql to see session and SQL information. This will show the SID for the session that is holding a PL/SQL package: -
select x.sid from v$session x, v$sqltext y
where x.sql_address = y.address and y.sql_text like '%
Display distinct multiple columns with SQL: -
select deptno, loc, job, sal, ename from lsc_emp
join lsc_dept
using (deptno)
order by deptno,loc,job,sal,ename;
The fuser command will show all UNIX process ID’s that are accessing any Oracle data file: -
root> fuser –u /u01/app/oracle/myfile.dbf
/u01/app/oracle/myfile.dbf 1234(user1) 2345(user2) 5678(user3)
db uptime :-
select
'Hostname : ' || host_name
,'Instance Name : ' || instance_name
,'Started At : ' || to_char(startup_time,'DD-MON-YYYY HH24:MI:SS') stime
,'Uptime : ' || floor(sysdate - startup_time) || ' days(s) ' ||
trunc( 24*((sysdate-startup_time) -
trunc(sysdate-startup_time))) || ' hour(s) ' ||
mod(trunc(1440*((sysdate-startup_time) -
trunc(sysdate-startup_time))), 60) ||' minute(s) ' ||
mod(trunc(86400*((sysdate-startup_time) -
trunc(sysdate-startup_time))), 60) ||' seconds' uptime
from
sys.v_$instance;
(or)
select to_char(logon_time,'DD/MM/YYYY HH24:MI:SS') from v$session
where sid=1;
How to display your Oracle session ID number: -
select sys_context('USERENV','SID') from dual;
select sid from v$mystat where rownum <=1;
select to_number(substr(dbms_session.unique_session_id,1,4),'XXXX') mysid from dual;
select distinct sid from v$mystat;
How to share and Access file on Solaris machine
In this example I will share a file from jupiter machine and then access it on neptune machine. Both machine uses Solaris platform.
1)On jupiter machine,
bash-3.00$ hostname
jupiter
Log on as a root user,
bash-3.00$ su
Password:
Change shell to bash
# bash
To make share persistence (after reboot is will also show) edit /etc/dfs/dfstab entry. Here I want to share directory /export/home/oracle and sharing option is read write.
# vi /etc/dfs/dfstab
share -F nfs -o rw /export/home/oracle
rw means read write permission You can also want to give ro (read only) instead of read write.
If you want it temporary you can do,
# share -F nfs -o rw /export/home/oracle
Restart your nfs server.
# /etc/init.d/nfs.server stop
# /etc/init.d/nfs.server start
Have a look at whether nfs server is running or not.
# ps -ef | grep nfs
daemon 317 1 0 Oct 10 ? 0:00 /usr/lib/nfs/lockd
daemon 311 1 0 Oct 10 ? 0:00 /usr/lib/nfs/statd
daemon 313 1 0 Oct 10 ? 0:03 /usr/lib/nfs/nfsmapid
daemon 291 1 0 Oct 10 ? 0:00 /usr/lib/nfs/nfs4cbd
root 12741 12424 0 03:20:34 pts/4 0:00 grep nfs
This must show statd and lockd running. In fact The statd and lockd must be running on server and
client.
Have a look at which file is shared and it's mode.
# share
- /export/home/oracle rw ""
2)On Saturn machine log on as a root user
oracle@neptune ~$ su -
Password:
Create a directory where you mount the network location.
root@neptune /# mkdir /export/home/oracle/remote
Mount the network drive
root@neptune /# mount -F nfs jupiter:/export/home/oracle /export/home/oracle/remote
Or, with more options issue,
# mount -o rw,bg,hard,nointr,rsize=32768,wsize=32768,tcp,vers=3,timeo=600,actimeo=0 jupiter:/export/home/oracle /export/home/oracle/remote
See whether it is mounted.
root@neptune /# df -h
.
.
jupiter:/export/home/oracle
20G 7.6G 12G 39% /export/home/oracle/remote
No comments:
Post a Comment