Hard drive speed test using Linux command line and hdparm

Note that all tests should be run multiple times and average time should be calculated to get more accurate result.

Bypassing hard drive’s buffer cache memory thus reading directly from the disk.

Read data from the second half of the disk that is if the hard drive size is 100GB.

To obtain cached reads run the following command:

Ftp ACL (Access Control Lists ) – restricted FTP access

What is ACL ?

When you enable it , only selected ips  have access to  FTP server as a client.  it is for security of FTP. if some one stole  your FTP.


How to ?  It is depends on your FTP  provider. But if you have  own linux server.

access-list 101 permit tcp any any eq 21  
!--- The above line permits TCP traffic from any source, such as the FTP client,
!--- FTP server destination at the FTP control port 21. 

access-list 101 permit tcp any eq 20 any
!--- The above line permits TCP traffic from any source, such as the FTP server,
!--- FTP client at FTP data port 20.


Example Document :



Posted in FTP

Linux Init Processes

The Linux Init Processes:

The init process is the last step in the boot procedure and identified by process id “1”. Init is responsible for starting system processes as defined in the /etc/inittab file. Init typically will start multiple instances of “getty” which waits for console logins which spawn one’s user shell process. Upon shutdown, init controls the sequence and processes for shutdown. The init process is never shut down. It is a user process and not a kernel system process although it does run as root.

System Processes:

Process ID Description
0 The Scheduler
1 The init process
2 kflushd
3 kupdate
4 kpiod
5 kswapd
6 mdrecoveryd

Network Filesystems

NFS Sun’s Network Filesystem (NFS) is the preferred method of file sharing for networks of Unix or Linux computers. The Linux kernel includes both NFS client support

Coda This is an advanced network filesystem that supports features omitted from NFS. These features include better security (including encryption) and improved caching.

SMB/CIFS The Server Message Block (SMB) protocol, which has been renamed the Core Internet Filesystem (CIFS), is the usual means of network file sharing among Microsoft OSs. The Linux kernel includes SMB/CIFS client support, so you can mount SMB/CIFS shares. You can configure your Linux computer as an SMB/CIFS server using the Samba package (http://www.samba.org). The filesystem type code for SMB/CIFS shares is smbfs.

NCP The NetWare Core Protocol (NCP) is NetWare’s file sharing protocol. As with SMB/CIFS, Linux includes basic NCP client support in the kernel, and you can add separate server packages to turn Linux into an NCP server. NCP’s filesystem type code is ncpfs.

Unix System Formatting Tools –

 Formating Tools

Table 7. Formating Tools

Tool Requirements Description
e2fsck Included in tomsrtbt-1.6.335 Checks an ext2 filesystem for errors
format Included with Windows 95 and Windows 98 Creates a vfat filesystem on a chosen partition
mke2fs Included in tomsrtbt-1.6.335 Creates an ext2 filesystem on a chosen partition.
mkswap Included in tomsrtbt-1.6.335 Creates a swap filesystem on a chosen partition.