Category: Network & Server (網絡及服務器)

Reset CentOS 7 root Password

By admin, April 30, 2018 13:14

1. Menu press “e”
2. Find the line “linux16 vmlinuz…: at the end add “init=/bin/sh”, then Ctrl + x
3. mount -o remount,rw /
4. passwd root
5. touch /.autorelabel
6. exec /sbin/init (You will need to WAIT for a few minutes)


By admin, December 3, 2017 10:17



No GUI and SSH login on console, only [sda] Assuming drive cache: write through

By admin, October 11, 2017 13:05

Today I found out one of the CentOS 7-1611 VMs has no GUI available and also there is no SSH login at the console.

Worst the screen indicates “[sda] Assuming drive cache: write through”, seems it’s hang at startup.

In fact it’s working fine, then I SSH into the server remotely, and issue “systemctl set-default” which set the default login interface to be text based SSH login, the SSH login screen appears after the reboot.

systemctl isolate to return to command mode
systemctl isolate  to return to graphical mode

Somehow, systemctl isolate turns the screen into blank, still have no idea what’s causing this, nor startx works.

Finally, the vCenter VM Guest OS status changed from CentOS 4/5 64 bits to Other (32-bit) automatically everything after reboot, anyone knows why? Pls drop me a line, thx.


By admin, October 10, 2017 14:24




WannaCry Hot Fix for Windows XP!

By admin, June 7, 2017 16:17

Definitely a big surprise from M$ to release a hotfix for WannaCry for all their EOL products!


When Dell Runs Out of Stock

By admin, June 1, 2017 19:10

This is what my friends showed to me recently.

When Dell ran out of Equallogic disks (15K RPM, 600GB 3.5″ SAS), they supplied him with this alternative solution.

A 2.5″ 15K RPM, 600GB SAS!



This is how it fits into the original 3.5″ tray, seems the tray is a revised version with 4 new holes on the back in order to fit that 2.5″ SAS disk.



Running Multiple PHP Versions on Windows Server

By admin, May 25, 2017 00:33

The trick is to create an extra environment variable PHPRC and point to the specific PHP version directory that contains php.ini.

* DO NOT put an extra \ at the end, ie, C:\Program Files (x86)\PHP 7.1.5 is the correct form without the ending \.

* Make sure you downloaded the Non-Thread Safe x86 version for PHP release


Extra Note:

For FastCGI on Windows Server 2003, the last supported binary Non-Thread Safe x86 version of PHP is 5.4.9. (ie,

Enable the User-Defined INI files

If you want to allow Web application owners to control PHP settings themselves, you can enable a user-defined PHP configuration.

  1. Add the following setting, which specifies the name to be used for user-specific INI files, to the main php.ini file. Setting this to an empty value disables the user-defined PHP configuration.

    user_ini.filename = .user.ini
  2. Create a file called .user.ini in C:\inetpub\\ folder, and add the following:

    max_execution_time = 300
  3. Add the following to the file .user.ini in C:\inetpub\\ folder:

    upload_max_filesize = 12M

    Note that if your main php.ini file has [PATH] sections that point to the root folders of these sites, then you need to remove those sections; if you do not remove those sections, the user-defined settings will not take effect.

  4. Use phpinfo() or ini_get(”max_execution_time”) to check that the new settings have overwritten the default settings. Create a PHP file with the following text and save it in the Web root folder:

    <?php phpinfo(); ?>
  5. Open the PHP script on the Web site http://localhost/phpinfo.php.

  6. Note also that when you enable the user-defined INI files, the settings in those files are cached by the PHP engine to avoid re-reading those files for every request. This means that if the user makes a change to .user.ini file, then that change may not take effect right away. Instead it may take effect after the cache time to live (TTL) has expired. The cache TTL value is controlled by the php.ini setting user_ini.cache_ttl, which is set to 300 seconds (5 minutes) by default.

Fore detail, please refer to Enable Per-Site PHP Configuration on IIS 7.

PHP Security Recommendations

By admin, May 19, 2017 13:09

The following settings can be used to tighten the security of a PHP installation. To make the recommended changes, locate and open the php.ini file and edit the configuration settings as described below:

Setting Description
allow_url_fopen=Off allow_url_include=Off Disable remote URLs for file handling functions, which may cause code injection vulnerabilities.
register_globals=Off Disable register_globals.
open_basedir=”c:\inetpub\” Restrict where PHP processes can read and write on a file system.
safe_mode=Off safe_mode_gid=Off Disable safe mode.
max_execution_time=30 max_input_time=60 Limit script execution time.
memory_limit=16M upload_max_filesize=2M post_max_size=8M max_input_nesting_levels=64 Limit memory usage and file sizes.
display_errors=Off log_errors=On error_log=”C:\path\of\your\choice” Configure error messages and logging.
fastcgi.logging=0 The IIS FastCGI module will fail the request when PHP sends any data on stderr by using the FastCGI protocol. Disable FastCGI logging to prevent PHP from sending error information over stderr and generating 500 response codes for the client.
expose_php=Off Hide the presence of PHP.

CentOS 7 NIC is “Off” after reboot

By admin, May 15, 2017 21:43

Got a surprise today! It turns out this is the default policy for the new CentOS, all you need is to modify /etc/sysconfig/network-scripts/ifcfg-eth0 and change ONBOOT=no to ONBOOT=yes. In additional Static IP setups would need to set BOOTPROTO=static.

How to Clear a Equallogic RAID label via a CLI command

By admin, April 24, 2017 12:24

GrpName> mem sel <member name> disk select 0

GrpName(member_MEMBERNAME disk_0)> ?

clear-label          - Clears the label on the selected disk if the disk contai

Just make DOUBLE sure you have the correct drive number.  Remember first drive number is ZERO (0) not one (1).

You can issue it as one command.  mem sel membername disk select <number> clear-label

However, I prefer to select the drive first.  Then do a “show” to make sure it’s the disk I want.


______________________________ Disk Information _______________________________

Slot: 0                                Status: spare

Model: ST900MM0006                     Revision: LE09

Size: 838.36GB                         Errors: 0

Rpm: 10000                             SectorSize: 512

Health: ok

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