Lowyat.NET: Latest topics by MadCentury

Power Supply wire and output amp

MadCentury — Sun, 28 Dec 2008 02:27:40 +0800

i have a HP server power supply, from the label i can see +5V / 19A Level3, +12V /25A Level5, +3.3V /14A Level3 and the rest are -v. from the power supply i got 5 yellow cable +12V, 5 red cable +5 and .....

any one could tell me from the label stated +12v /25AMP is for each yellow cable mean ( 5 * 25 = 110AMP total) or 12AMP for the 6 cable? and what is the level 3 and level 5 mean?

VMware ESX Server Running on normal PC

MadCentury — Sat, 02 Sep 2006 23:47:00 +0800

i m trying to install a ESX server into my normall intel base P4 box. i manage to make my both nic card work but the vmfs2 not able to format under IDE harddisk, without vmfs2 i cant deploy a virtual machine.

from the vmware forum i found some of the sata raid controller or sata controller will work as scsi in the vmware ESX server. this will save me a lot of money for buying SCSI harddisk that double the price.

i found some of the adaptec or other sata controller that cost me around 800 to 2000. that is still too much for me to use that server as a trainning server.

if anyone of you have try any of the cheap sata controller pci card that work in ESX server please let me know

thank you.

AIX 5.3L Virtual Ip Setup!

MadCentury — Wed, 15 Mar 2006 00:03:36 +0800

currently i try to configure a virtual ip, i have en0 and en1 network interface. i created a vi0 at the "smitty" after the vi0 sucessfull created i m unable to ping the virtual ip from other host, i comfirm the vi0 is up and running but it just cant ping the ip from other hosts, can anyone help me on this?

raid1 swap or normall swap partition?

MadCentury — Fri, 11 Nov 2005 10:01:59 +0800

Currently I found some information in the web regarding about two method of mirroring swap partition.

As we know swap partition is important if serves ram is running low, it is visual memory that if the ram is fully utilized system will store information in swap partition. Because of Linux memory management is far better than MS windows, so Linux will use this swap partition when the ram is fully utilized.

Now come with raid1, some people created swap partition in one of the hard disk as below

Disk array Sda1, Sdb1 md0 ext3

Sda1 Raid Partition
Sda2 swap Partition

Sdb1 Raid Partition

The above setting will cause problem if the hard disk which the swap partition located is failures, if between the failures period there is some active information stored in swap partition, than you will lost data or even system corrupt.

The second method is creating a swap raid partition. This should look like below

Disk array Sda1, Sdb1 md0 ext3
Sda2, Sdb2 md1 swap

Sda1 Raid Partition
Sda2 Raid Partition

Sdb1 Raid Partition
Sdn2 Raid Partition

There is a lot people claim that the above method will cause the system run very slow, I personally never try this.

The third method is what I prefer. Some Linux expert said by using this method will improve the speed. Mirroring the swap partition is actually built in kernel already. That is no need using raid 1 to mirroring the swap partition. Just make all swap partition to the same priority, the kernel will simply write the information to the all swap partition in parallel.

Disk array Sda1, Sdb1 md0 ext3

Sda1 Raid Partition
Sda2 Swap Partition
Sdb1 Raid Partition
Sdb2 Swap Partition

So far by using the third method my swap partition is "USED 0 ", this is impossible. At least a few hundred bytes should be used, I tried install in two Linux server, one using the third method mention above, another is use automatic partition at single hard disk which mean no raid 1 used. I install the same software and the server performs the same task. The result is the server which running raid 1 are showed 0 bytes swap used, another without raid 1 the swap partition is 1060 bytes used. Those servers are same memory and CPU.

I think I must be made some mistake to cause the swap partition not usable. Anyone who had experience please share your knowledge and point out my mistake, any comments and advise is welcome.

Thank you

WINDOWS Update VIA SQUID PROBLEM

MadCentury — Fri, 09 Sep 2005 22:00:13 +0800

any one got problem with windows update when connect to the squid proxy server?

windows cant download the update file!!

View Squid caching file

MadCentury — Wed, 31 Aug 2005 16:46:12 +0800

any one know that any software able to read the picture, flash or any other file that cached by squid proxy, i knew the the file all stored in /var/spool/squid/..... but i cant read it!

thank you,

Linux Routing Problem

MadCentury — Tue, 28 Jun 2005 04:40:02 +0800

i use iptable to do NAT, so i can share my 2M internet line to the rest of my company network. something strange is most of the time intenet connection is very slow. sometime cant even load a simple website. some time it load very fast.

and also the MSN and mirc, sometime i able to connect it and sometime i didnt. i pretty sure my NATing is correctly.

anyone have the similiar problem? please help me

squid ? or anything else?

MadCentury — Wed, 22 Jun 2005 23:35:59 +0800

anyone know how's the hotel boardband control system work? when guest plug the Lan cable to their pc, they will redirected to the welcome page and require the guest key in the password and user inorder to use.

anyone know did linux able to do such things by using squid? iptables? or....??

Linux Squid Server with Outlook

MadCentury — Sat, 12 Mar 2005 17:30:05 +0800

does anyone know how to configure the Linux Squid proxy server to allow microsoft outlook express to receive mail?