Study Notes

Play a directory contains music files (mp3,wmv) by issuing the following command:
# mplayer /mnt/c/0701
mplayer will play all the music in order automaticlly.It’s funny and convienence.
In this morning ,listening soft music makes my heart clear, in other words, reset myself operating system.I always consider that peope is such system with high advanced spirits.

How to display Chinese language in lynx browser? In my home machine whose operating system is Fedora Core 3,I could not display Chinese of both GB2312 and Big5. When I installed lynx in the office, by updating packages supplied by Red Hat 9.0 CD2,it will be fine where system environment is supporting Chinese.
However,this only can be tested successfullly in the terminal when X service has beening runing.In the console mode,lynx could only work well with English language.It’s annoy.

If no response when issue the rpm command,we can resolve in this way:
# rm -rf /var/lib/rpm/-db.*

Checking which program was running in the port22,
# lsof -i :22
lsof means list open files.Using the following commands to identify which programs are running in the defined process’s name and ID:
# lsof -c processe’s name
# lsof -p PID (process’s ID)

For high security,I created user count name “Phillip”.when I log with this user,
and open a new terminal, issue the commands:
#su root
Password:
#fdisk -l (and df, ifconfig so on)
bash:fdisk:command not find.
Attention! There is nothing between string “su” and “root”.I modified this command : # su – root (there are a blankspace between the “-” and “root”,it is very important). and then execute those commands like fdisk,df,ifconfig, everything is ok now.

If the system cannot connect to the Internet through the ethernet device is installed rightly and has been activate,we can try to find the error reason in the following way:
# ping itself(192.168.1.x,or 127.0.0.1)
# ping default gateway
# tracerouter DNS server’s IP address
and if all the above testing was passed,issue the following commands:
# nslookup www.163.com
# ping www.163.com
# tracerouter www.163.com
Using 163.com to test error happens in which step.

Gateway:192.168.1.0 equals 255.255.255.0

#host
#host -t MX powerleader.com.cn
powerleader.com.cn mail is handled by 10 mail.powerleader.com.cn
powerleader.com.cn mail is handled by 5 mailgate powerleader.com.cn

Watching the router’s infomation:
# netstat -n
# router -n
netstat: print network connections,routing tables,interface,statistics,masquerade connections and multiacst memberships.

Identify which mode the Fiber device is working in:
# getconf WORD_BIT
the result is 32 in my PC which is 32bit system in the office,and will be 64 (bit) in those 64bit platform.

In Fedora Core 3, I installed mplayer with rpm package. Issuing the following command to play DVD programs:

# cat /etc/fstab  

Identify the dvd mounting point.For example, the location is /dev/hdc.

# mplayer /dev/hdc

Then a playing windown jumpes out, and it will play the DVD .However , I still could not play the file as wmv format. I found the reason may be mplayer should get better performance through compliering installation which will get play in higher quarlity and I/O rate.Realplay10 for linux also be installed in my computer,but I can only hear the voice,no picture displayes.I have not found the key to resolve this problem.

Fedora 1 in SE7520JR2
After installing Fedora1 in SE7520JR2(PR2700) platform, I try to add two ethernet device which are Marvell and Intel Pro1000 to the operating system.First,Intel Pro1000 device was choose to install, at final step,I issue the following command:insmod e1000, in order to add device to the running kernel.Second,complied the Marvell source code.But some thing wrong happened.Only one ethernet device was found in the module list through executing the command:

#dmesg | grep eth

So I changed the queue .Install Marvell at first and then install Intel Pro1000 device.Hmmm,

#lsmod sk98lin          
- dedicate the Marvell ethernet deviee was active.
#lsmod e1000            
- in this way,I found e1000 module was unused.

Then, I used the command:

#ifconfig eth1 up

One ethernet device(Marvell) was found in the network device list,but two hardware recognized by the Linux were listed.

#cd /etc/sysconfig/network-script
#cp ifcfg-eth0 ifcfg-eth1

and edit parameters in ifcfg-eht1.

# service network restart

OK,two network devices were installed successfully.

What is patch? Apply a diff file to an original.
What is hwclock? Query and set the hardware clock.

In RedHat Linux,issue the following command to modify the time or date:
#timeconfig
select Asica/Shanghai
#ntpdate
sync the time with the specified time server
#date

Instead of strings in vi tools:
:%s/string/new_string/8

Check the running leve:
#runlever
I issue this command in GUI of Linux 9.0, the result was 3.

Identify the logining user:
#who am i
#whoami print effective user id
#id print read and effective UIDs and GIDs

We can create and edit this file “/etc/motd” to display own messages when login in.

What is “NONUS”? It means non-US.
Execute the following command to reset the language of system:
# export LANG=”en-US”
Sometimes,this method resolves some Code displaying matters.

Lynx is a type of browser in text mode running in terminal.Download the install package named as “.tar,gz” from internet, and then issue the following commands:

# tar zxvf  lynx-2.8.4dev.19.tar.gz
# cd /lynx-2.8.4
# ./configure
# make  

After executed the final command, the Lynx was installed in the system successfully.Opening a new terminal or hit “ctrl + alt + F2”, issues the “lynx”,and then ,we will get in a text mode browser.Its default homepage is “www.lynxbrowser.org”,we can just modify the startpage in the file which is located on “/usr/local/lib/lynx.cfg” or “$home/lynx-2.8.4/lynx.cfg”.Both of above two files are linked to one file in fact.
I tried to change the language setting to display simplify Chinese and traditional Chinese,but failed.As result,it seems only English would have been supported.In the Lynx browser,it does not show the pictures and flash movies,so it speeds up the opening rate greatly.I think it would be more useful in those machines which run very slowly,for example,486 or higher computers.

This afternoon,Cao Sheng and I went to UP Co. in order to resolve the fiber ether devices installing problem.The customer said he did what I’ve told him to do by email of yesterday.He selected the packages and installed the operating system as Red Hat Linux 9.0, but had found no ethernet device afer rebooting when completed installing processing. In the UP lab, I installed the operating system again by myself,and issued the following command:

# insmod e1000

which I thought the customer did not do this job after issuing “make install”.Before I executed the insmod command, I found no ethernet device by issuing “ifconfig” which is used to checking the net device.After issuing this command,and then check the ethernet devices again :

# ifconfig
# service network restart   

or

# /etc/rc.d/init.d/network reload

the ethernet devices were listed in the terminal or Network interface in GNOME.
Using ping command to identify these device,they runs OK.

SaX2 of SuSE Linux is used to configure the hardware’s parameter,for example,graphics card,ethernet device.SaX2 acts as like Devices Administrator in Windows.
Yast administrates the files throught GUI which like Source Explorer in Windows.

“The device has been validated to run at 80MB/s and should support,(**) 320MB/s when the operating system is loaded” . Configure the RAID0 included two harddisk and left one disk.

What’s LVD?Low Voltage Differential.

#hostname 
#vi /etc/sysconfig/hostname

Using the above commands to show or set the system’s host name.

#vi /etc/inittab

find the strings like “id:x initdefault”. x=3 means startup in text mode,and x=5 means GUI mode.We could configure the x parameter to decide the mode which we want Linux to start in.

mount ISO files

#mount -o loop /abc.iso /mnt/cdrom

mount DVD.

#mount -t iso9660 /dev/dvd /mnt/cdrom
#mount -t udf /dev/dvd /mnt/cdrom

Check hardware info:

#cat /proc/cpuinfo
#cat /proc/meminfo
#cat /proc/interrupt
#cat /proc/ioports
#cat /proc/partitions         
#cat /proc/pci
#cat /proc/swaps

To configure the language of system.

#vi /etc/sysconfig/i18n

Convert cdrom files to ISO files.

#cp /dev/cdrom *.iso
#dd if=/dev/cdrom of=/tmp/*.iso

SMP: symmetric multiple processor
UP : unique process
bigmem: support memory which is more than 1G.

View the color setting by default.

#dircolor -p

If want to install other language package after completing install system,we would insert the RH 9.0 CD3, and then find the specific language package.

To select or un-select the service running.

#chkconfig --list
#ntsysc
#setup

RedHat 9.0 common packages installed:
Desktop:
-X window system
-GNOME Desktop Environment
Application:
-None
Servers:
-None
Development:
-Development Tools
-Kernel Development
-X software Development
System
-Administration Tools
-System Tools

We can remember these packages by the numeric strings “2-3-2”.

PR2510 is based on Intel 7520BD2 server broad.There are total four SCSI harddisks.The customer need three disks to form RAID0 and install Windows server 2003.After configuring the parameter of LSI SCSI,the following messages displayed in the screen:the partition of RAID0 by three disks has 320MB/s rate,however the left one harddisk’s rate is only 80M/S! Below the rate list,these texts displayed: The harddisk is 80M/S,and will support 320M/s when operation system is loaded.

Tang said the state is not error.I will read the LSI documents to probe his words.

Server Platform: Intel 7520JR2
Operating system: Red Hat Linux 9.0(2.4.20)

Using the following commands to install Intel 82545 ethernet card who driver is same as Intel 82546(The board has two 82546 ethernet card,and we added four 82545 card through external card inserted in two slots).

# make install

Configure eth0’s IP and name

# vi /etc/sysconfig/networking-scripts/ifeth0

Copy the driver file for eth1,because they use same drivers.

# cp ifeth0 ifeth1

Configure eth1’s parameter,change the IP and name

# vi /etc/sysconfig/networking-scripts/ifeth1

Copy the driver file for eth2,because they use same drivers.

# cp ifeth0 ifeth2

Configure eth2’s parameter,change the IP and name

# vi /etc/sysconfig/networking-scripts/ifeth2 

……
Copy the driver file for eth5,because they use same drivers.

# cp ifeth0 ifeth5

Configure eth5’s parameter,change the IP and name

# vi /etc/sysconfig/networking-scripts/ifeth5 

Identify whether these devices are installed correctly

 # service network restart

or

# /etc/rc.d/init.d/network reload 

In the PT6250 which is based in Intel SE7221BA1-E platform,using the following command to reflash bios: iflash. Before sending our server machines to the customers,the products’s bios logo would be reflashed with specificed sign which even maybe of OEM’s logo.We usually make updating bios file with ITK tools introduced by Intel.Note,it is necessarily to set the firmware parameter from 4 mega to 8 mega if we use ITK 2.7 to make SE7221’s new bios file.And then,adding the specified picture that is bmp or jpg formation.At last,generate the new bios file and save it to the harddisk.

There will be some trouble when using a picture with deep blue,red or green.The SE7221’s bios program does not support these deep color blocks as well as other light colors such as sky blue.However,as productors,we could not change the logo picture of the customers.
Perhaps contacting with Intel’s TME could resolve this problem.

Other server broad,for example, SE7520BD2 platform,using “run” command with “.rom” file to reflash the BIOS.The latest bios release of SE7520BD2 is 7.40.

A customer requested for proving four FiberCards which are using two external cards in different slots could be installed in the same SE7520JR2 platform.The Operating system the customer said is Linux 8.0. In the supporting operating system lists of SE7520JR2,I found no recorders about Linux 8.0,but Red Linux 9.0,AS 2.1u4, AS 3.0(u1 or u3) and SUSE series exist in this table.I plan to install this four Fiber netcard in Windown system to identify whether the platform hardware could support these devices or not.

Some identified port list: SMTP 25,POP 110, DNS 53, Web 80, FTP 21 or 23, SSH 22.
IP tunneling,which is supported in router and switch software involves encapsulating a packet supporting one protocol with another packet that run the same or a different protocol.
Key components of tunneling:tunneled protocol, transport protocol, multiplexing identifier.

Load balancing feature: High availiability, Scalability.High availability can be defined as redundancy.Scalability is an application’s ability to support a growing number of users.Of the many methods available to balance a server load, the main two are DNS round robin and Hardware load balancers.Each of them has its own advantages and disadvantages.DNS round robin make several IP address directing to the same logic IP, in the scene,all the nodes combine as one to user transparently.This method only distributes IP to every node,but not distribute actural load to nodes because the load of each connect will not be same.

The problem is thart brower caches that server’s IP address.Once the cache expires the broweer make another request to the DNS server for the IP address associated with the domain name.If the DNS server returns a different IP address that of anther server in the cluster.The session information is lost.Changes to the cluster take time to propagate.One reason is that many large organizations,ISPs,coporations,agencies cache their DNS request to reduce netword traffic and request time.When a user within these organizations make a DNS request,it’s checked against the cache’s list of DNS names mapped to IP addresses.If if finds an entry,it returns the IP address to the user.If the entry is not found in its local cache,the ISP send this DNS request to the DNS server and caches response.

When a cached entry expires,the ISP updates its local database by contacting other DNS servers.When your list of servers changes,it can take a while for the cached entries on other organization’s network to expire and look for the updated list of servers.During that period,a client can still attempt to hit the downed server mode,if that client’s ISP still has an entry pointing to it.In such a case,some users of that ISP could not access your site on their first attempt,even if your cluster has rundundant servers up and running.

This is a bigger problem when removing a node than when adding one.When you drop a node,a user may be trying to hit a non-existing server.When you add one, the server may just be under-utilized until its IP address proprogates to all the DNS servers.Although this method tried to balance the number of users on each server,it doesn’t necessarily balance the server load.Some user could demand a high load of activity during their session than uses on another servers.The electrocircuit module suppling processor power in the mainbroad is called VRM.

My favorite star Chirisitian Vieri joins Milan!
Welcome, super Bobo !!!

VIERI JOINS MILAN!
7/5/2005 3:52:00 PM

Christian Vieri is a Milan player. It is finally official. After many talks and rumours, the striker is certain he will wear a red-and-black shirt for the next two seasons. The Italian international, who was released by Inter earlier this week, will find again new enthusiasm and stimulation in a dressing-room where he has known most of the components for a long time. Bobo has scored 179 goals in his professional career, playing in ten different clubs. He made his debut in Serie A at the early age of 17 for Torino. In his first year, he collected six appearances and netted one goal, having all the eyes on him in Italy. The boy from Bologna immediately showed character and the following season, after playing only one game with the Granata side, moved to Pisa in Serie B. He totalled 18 appearances and two nets with the Tuscan side before joining Ravenna the following year. There he estabilished his first goal record in the league, scoring 12 strikes in 32 matches. The attention on him was growing more and more, and with time passing, his qualities emerged distinctly: strength, courage, and ability in the air. Another move the following season and Bobo played his last campaign in Serie B at Venezia where he made 29 appearances and netted 11 goals. The first club who really trusted Christian’s abilities was Atalanta who brought him back in the top flight. In Bergamo he played 19 games and scored only seven goals, but this was just enough for him to win over Juventus who signed him for the following campaign. For the Bianconeri Bobo played 23 games and scored eight goals, with the fans rising against the club when they decided to sell him abroad to Atletico Madrid at the end of the season. In his Spanish experience, under the reign of Arrigo Sacchi, Vieri set a new goal record in the league: an amazing 24 goals in 24 games. But he soon missed the Italian football, and to come back home he accepted the courting of Lazio. In the capital he added 12 more nets to his overall tally, playing 12 games with the Biancocelesti. The most recent part of his career was at Inter who made great sacrifices to sign him. After six years enriched with plenty of goals and appearances, the forward, who will turn 32-year-old next week, has decided to take part from the Nerazzurri. It is summer 2005, the turning point. And Bobo agrees the Milan switch.