System Admin Profile

Scan Opened TCP Ports Based on Server Name List Script

2010-12-03T12:34:00.000-08:00

In order to see if the server is sql server or other port is listening, the following script can scan the port based on the server list.

#!/usr/bin/perl -w

use IO::Socket;
use strict;
my $debug = 0;
my $servername='';
my @ports=('2025','1433');

open(SERVERNAME,"sqlserver.log");

while ($servername=<SERVERNAME>){

        chomp $servername;
        print "scaning server:$servername .....\n\n" if $debug;

        foreach my $port (@ports){

          my $sock = new IO::Socket::INET (
                PeerAddr => $servername,
                PeerPort => $port,
                Proto => 'tcp');
          if (! $sock ) {
                print "ServerName:$servername:$!\n" if $debug
          }else {
                print "ServerName:$servername:OPENED:$port\n";
                close($sock);
          }
        }
}
close(SERVERNAME);

Install Naigos NPRE and Nagios Plugin on AIX 6.1

2010-12-03T11:24:00.000-08:00

Failed on compiling from source code and ran out of time to troubleshoot the source code. Then went to pre-compiled solution.

The following procedure has been tested and it working on my box at least.

Install Naigos NPRE and Nagios Plugin on AIX 6.1

Written on 12/3/2010

1. Download nagios plugin and NREP precompiled binary from http://www.guntram.de/nagios/.

2. install them into /usr/loacl/nagios folder.

3. Configure NRPE running with /etc/rc.local

edit nrpe.cfg file to put your customization there.

# mkitab -i rcnfs "rclocal:2:wait:/etc/rc.local >/dev/console 2>&1"
# touch /etc/rc.local
# chmod 700 /etc/rc.local

Then put the command lines to start the daemons in /etc/rc.local.

nohup /usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d

Reference:

http://linuxdocument.blogspot.com/2010/03/installing-nrpe-212-on-aix.html
http://www.guntram.de/nagios/
http://saifulaziz.wordpress.com/2006/12/06/how-do-i-start-local-daemons-at-aix-system-startup/

setup a CA to self-sign the SSL cert.

2007-07-05T14:46:00.001-07:00

1. download a Openssl For windows binaries and source package
http://sourceforge.net/project/showfiles.php?group_id=23617&release_id=188569

2. unzip both of the OpenSSL packages to temporary folders. From the binaries package "bin" folder, copy the files "openssl.exe" and the two DLLs into the source package's "apps" folder.

In the "apps" folder is a file called CA.pl. Open this perl script in a text editor and change the line

$SSLEAY_CONFIG=$ENV{"SSLEAY_CONFIG"};
to
$SSLEAY_CONFIG="-config openssl.cnf";

3. Copy the cert request file to into this "apps" directory, and rename it to "newreq.pem".

Next, open a command prompt window in the apps directory, and run the following commands:

* perl CA.pl -newca
* perl CA.pl -signreq

$ perl CA.pl -newca

sg22785@maximus-a7juw9u ~/openssl-0.9.7c-src/src/openssl-0.9.7c/apps
$ perl CA.pl -signreq
Using configuration from openssl.cnf
Check that the request matches the signature
Signature ok
Certificate Details:
Serial Number: 1 (0x1)
Validity
Not Before: Jul 5 20:24:25 2007 GMT
Not After : Jul 4 20:24:25 2008 GMT
Subject:
countryName = US
stateOrProvinceName = California
localityName = Los Angeles
organizationName = MAXIMUS
organizationalUnitName = Education
commonName = lasttmp1.schoolmax.net
X509v3 extensions:
X509v3 Basic Constraints:
CA:FALSE
Netscape Comment:
OpenSSL Generated Certificate
X509v3 Subject Key Identifier:
D2:AD:D2:27:2A:52:BD:67:1A:BF:4A:65:8E:E8:52:6E:D6:E7:B9:30
X509v3 Authority Key Identifier:
DirName:/C=AU/ST=QLD/CN=SSLeay/rsa test CA
serial:04

Certificate is to be certified until Jul 4 20:24:25 2008 GMT (365 days)
Sign the certificate? [y/n]:y

1 out of 1 certificate requests certified, commit? [y/n]y
Write out database with 1 new entries
Data Base Updated
Signed certificate is in newcert.pem

ORA-01555 error.

2007-06-28T15:33:00.000-07:00

Under the help from Wenson, the following ora-01555 has been fixed.

Errors in file D:\ora81\RDBMS\TRACE\ORA16184.TRC:
ORA-00604: error occurred at recursive SQL level 1
ORA-01555: snapshot too old: rollback segment number with name "" too small

Fix:

shutdown immeidate
startup mount
recover database
alter database open
or alter database open resetlogs

The Thinking from Wii

2007-06-25T21:46:00.000-07:00

An article on this month's issue of Fortune arouses my interests about Wii. The success story about Wii is really impressive - battling on the indifference of people who have no interest in video games. Wii focuses on delivering experiences with lower price rather than other gaming industry giants do, such as SNE and MSFT. Good game experience is not necessary to be expensive!

The first time I knew Wii was from a friend, Diedian's home. The little box is really something that is very attractive. The way that a player is playing the game and the sensitivity to the player's body movements are more accurate than I thought. I heard that Wii was also hard to get.

The target of the Wii's marketing segment is bald and I am not sure how long the successful trend can last. Since the target consumers are not game-sensitive, and this segment usually is composed of low value users of traditional electronic games. I am interested in how the product information can be spread to those people, and how much the target consumer are willing to pay for this box. Currently the list price is less than 300 US.

The "little" company's revenue is unbelievable-- 8.36 B with only 3,400 employees, almost 8 times of that of the company I work at, and just a little less than Mattel ( Barbie doll company) which has been in Market for more than 50 years, 2.5M per employee whereas 1M per employee at Google. I checked their website (http://www.nintendo.com) and wanted to check out how to invest this company. But they seem to be only traded in Japan. In US, we have to purchase ADR ( America Depository Receipt) from some banks. Never done any ADR trade before. Might investigate it more later on.

RHEL AS4 NFS client can not mount volum during the boot time.

2007-06-25T15:54:00.000-07:00

Symptom:

Got the following error in the /var/log/messages file during the boot. But after the boot manually mount is OK.

Jun 25 14:58:03 laappt6 mount: mount: mount to NFS server 'laappt3' failed:
Jun 25 14:58:03 laappt6 mount: System Error: No route to host.

Cause:

The NFS mount script runs during the network initialize phase.

Solution :

Found two solutions from web.

1. append "/bin/mount -a " in /etc/rc.d/rc.local

2. insert the following line in to /etc/rc.d/init.d/netfs file.

before :

[ ! -f /var/lock/subsys/portmap ] && service portmap start
action $"Mounting NFS filesystems: " mount -a -t nfs,nfs4

after :
[ ! -f /var/lock/subsys/portmap ] && service portmap start
#added by David W.
action $"Sleeping for 30 secs:" sleep 30
#end of added by David W.
action $"Mounting NFS filesystems: " mount -a -t nfs,nfs4

Reference:

1. CrazyToon,
http://crazytoon.com/2007/05/11/centos-and-redhat-problem-nfs-mount-at-boot-up-fails-with-error-system-error-no-route-to-host/

Use Microsfot iSCSI Initiator to access Openfiler

2007-06-22T10:29:00.000-07:00

The steps are straightforward .

1. download microsoft iscsi initiator and install it.
2. configure the target.
3. click target tab and make sure the disk is connected , otherwise, click logon.
4. use disk management on windows to format to assign a drive letter.

How to install kernel source on RHEL4

2007-06-21T00:38:00.000-07:00

http://kbase.redhat.com/faq/FAQ_79_8848.shtm

up2date --get-source kernel

Fetching all package list for channel: rhel-i386-as-4...
########################################

Fetching package list for channel: rhel-i386-as-4...
########################################

kernel-2.6.9-55.EL.src.rpm...

[root@RH4 up2date]# rpm -ivh kernel-2.6.9-55.EL.src.rpm
error: cannot create %sourcedir /usr/src/redhat/SOURCES
[root@RH4 up2date]# mkdir -p /usr/src/redhat/SOURCES
[root@RH4 up2date]#
[root@RH4 up2date]# rpm -ivh kernel-2.6.9-55.EL.src.rpm
1:kernel warning: user brewbuilder does not exist - using root
warning: group brewbuilder does not exist - using root

how to Mount iSCSI snapshot from openfiler

2007-06-21T00:12:00.000-07:00

after create the snapshot from the openfiler console. Check the /dev/vol1/ dir. found the snapshot device file name is :

of.snapshot.crs.snap

edit /etc/iedt.conf file to share the volume.

Target iqn.2006-01.com.openfiler:vol1.crs
Lun 0 Path=/dev/vol1/crs,Type=fileio
Lun 1 Path=/dev/vol1/of.snapshot.crs.snap,Type=fileio

Write out your changes and run the following:
# service iscsi-target restart
Stopping iSCSI target service: [ OK ]
Starting iSCSI target service: [ OK ]

Refresh / rescan your iSCSI initiator so it sees the snapshot as another drive.

[root@RH4 /]# fdisk -l

Disk /dev/sda: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 1044 8281507+ 8e Linux LVM

Disk /dev/sdb: 1006 MB, 1006632960 bytes
31 heads, 62 sectors/track, 1022 cylinders
Units = cylinders of 1922 * 512 = 984064 bytes

Device Boot Start End Blocks Id System
/dev/sdb1 1 1022 982111 83 Linux

Disk /dev/sdc: 1006 MB, 1006632960 bytes
31 heads, 62 sectors/track, 1022 cylinders
Units = cylinders of 1922 * 512 = 984064 bytes

Device Boot Start End Blocks Id System
/dev/sdc1 1 1022 982111 83 Linux

Then mount the partition with mount command.

Reference:
https://www.openfiler.com/community/forums/viewtopic.php?id=1124 by dtuneman

iSCSI on RHEL4 with openfiler issue

2007-06-20T21:09:00.000-07:00

Yesterday, felt good for successfully configured 2-node RAC on VMware 6 workstation. It took my 3 days to troubleshoot all the issues. Then, I think that using iscsi might be easier on configuration and more reliable. So after taking a look on someone's blogs regarding to iscsi. And noticed iscsi is a good stuff, so wanted to give a shot today.

Today, tried to install iscsi on RHEL AS4 with openfiler ( a freeware of NAS). But always could not attach the disk configured in openfiler from initiator.

installed iscsi-initiator-utils-4.0.3.0-4.i386.rpm, sysfsutils-1.2.0-1.i386.rpm

up2date iscsi-initiator-utils

On the target server:
under /opt/openfiler/etc/iscsi/, the xml file on the openfiler server is control the network privilege.
/opt/openfiler/etc/networks.xml file can delete the network configured . i could not find the place under openfiler to delete the network.
and also /etc/initiators.allow

Jun 20 19:36:37 RH4 iscsi: iscsi config check succeeded
Jun 20 19:36:37 RH4 kernel: iscsi-sfnet: Loading iscsi_sfnet version 4:0.1.11-3
Jun 20 19:36:37 RH4 kernel: iscsi-sfnet: Control device major number 254
Jun 20 19:36:37 RH4 iscsi: Loading iscsi driver: succeeded
Jun 20 19:36:43 RH4 iscsid[13333]: version 4:0.1.11-4 variant (15-Jan-2007)
Jun 20 19:36:43 RH4 iscsi: iscsid startup succeeded
Jun 20 19:36:43 RH4 iscsid[13338]: Connected to Discovery Address 10.1.72.125

but could not attach the disk.

If the network is not configured to be allowed access. the following error message will be showed up in initiator /var/log/messages file.

un 20 19:44:47 RH4 iscsid[14750]: cannot make connection to 10.1.72.125:3260: Connection refused
Jun 20 19:44:47 RH4 iscsid[14750]: Connection to Discovery Address 10.1.72.125 failed
Jun 20 19:44:52 RH4 iscsi: iscsid shutdown succeeded
Jun 20 19:44:52 RH4 iscsi: removing driver succeeded
Jun 20 19:44:55 RH4 iscsi: iscsi config check succeeded
Jun 20 19:44:55 RH4 kernel: iscsi-sfnet: Loading iscsi_sfnet version 4:0.1.11-3
Jun 20 19:44:55 RH4 kernel: iscsi-sfnet: Control device major number 254
Jun 20 19:44:55 RH4 iscsi: Loading iscsi driver: succeeded
Jun 20 19:45:01 RH4 iscsid[14880]: version 4:0.1.11-4 variant (15-Jan-2007)
Jun 20 19:45:01 RH4 iscsi: iscsid startup succeeded
Jun 20 19:45:01 RH4 iscsid[14884]: cannot make connection to 10.1.72.125:3260: Connection refused
Jun 20 19:45:01 RH4 iscsid[14884]: Connection to Discovery Address 10.1.72.125 failed
Jun 20 19:45:02 RH4 iscsid[14884]: cannot make connection to 10.1.72.125:3260: Connection refused
Jun 20 19:45:02 RH4 iscsid[14884]: Connection to Discovery Address 10.1.72.125 failed

if only configure target IP:

you get the following message, but can not discover the disk.

Jun 20 19:46:28 RH4 iscsi: iscsi config check succeeded
Jun 20 19:46:28 RH4 kernel: iscsi-sfnet: Loading iscsi_sfnet version 4:0.1.11-3
Jun 20 19:46:28 RH4 kernel: iscsi-sfnet: Control device major number 254
Jun 20 19:46:28 RH4 iscsi: Loading iscsi driver: succeeded
Jun 20 19:46:33 RH4 iscsid[15021]: version 4:0.1.11-4 variant (15-Jan-2007)
Jun 20 19:46:34 RH4 iscsi: iscsid startup succeeded
Jun 20 19:46:34 RH4 iscsid[15025]: Connected to Discovery Address 10.1.72.125

Even configured to allow the initialter's IP access, still can not find the disk.

After configure to allow the whole subnet to access the volume. the problem is solved!!

for example, configure 10.1.72.122/24 : failed. but 10.1.72.0/24 works!.

Then even removed 10.1.72.0/24 from networks.xml file. it still work. I believe that is a bug on openfiler.

command to restart target :

[root@localhost ~]# service iscsi-target restart
Stopping iSCSI target service: [ OK ]
Starting iSCSI target service: [ OK ]
[root@localhost ~]#

command to restart initiator on RHEL:
[root@RH4 etc]# service iscsi restart
Searching for iscsi-based multipath maps
Found 0 maps
Stopping iscsid: [ OK ]
Removing iscsi driver: [ OK ]
Checking iscsi config: [ OK ]
Loading iscsi driver: [ OK ]
mknod: `/dev/iscsictl': File exists
Starting iscsid: [ OK ]

After attached the disk, use the following command to list the iscsi device.

[root@RH4 etc]# iscsi-ls
*******************************************************************************
SFNet iSCSI Driver Version ...4:0.1.11-4(15-Jan-2007)
*******************************************************************************
TARGET NAME : iqn.2006-01.com.openfiler:vol1.crs
TARGET ALIAS :
HOST ID : 10
BUS ID : 0
TARGET ID : 0
TARGET ADDRESS : 10.1.72.125:3260,1
SESSION STATUS : ESTABLISHED AT Wed Jun 20 19:55:19 EDT 2007
SESSION ID : ISID 00023d000001 TSIH 200
*******************************************************************************

or

[root@RH4 etc]# iscsi-device /dev/sdb
/dev/sdb is an iSCSI device

My setting in /etc/iscsi.conf :

HeaderDigest=never
DataDigest=never
ImmediateData=yes
ConnFailTimeout=180
Continuous=no
DiscoveryAddress=10.1.72.125

then use fdisk /dev/sdb , n, p, 1 ... then w to partition the disk.

mke2fs -j -L  /dev/sdXY

It is extremely important to use disk labels when working with iSCSI storage. Delays in network traffic may cause the LUNs to be discovered in a different order the next time the system is booted. The only way to guarantee that the correct partition will be mounted at the proper mount point is to use disk labels to identify them.

[[root@RH4 mnt]# mke2fs -j -L idisk1 /dev/sdb1
mke2fs 1.35 (28-Feb-2004)
Filesystem label=idisk1
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
122880 inodes, 245527 blocks
12276 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=251658240
8 block groups
32768 blocks per group, 32768 fragments per group
15360 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376

Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 39 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override

mount -L idisk1 /mnt/data1

edit /etc/fstab to put the entry to mount this volume automatically.

LABEL=idisk1 /mnt/data1 ext3 _netdev 0 0

Reference:
1. Redhat Article ID: 7905
2. https://www.openfiler.com/doc/
3. Jeff Hunter's Oracle http://www.idevelopment.info/