drwxr-xr-x 3 root root 73728 Dec 26 08:39 /usr/bin/ <=== This directory file on an ext4 filesystem is listed in long format (ls -ld). The value of the fifth field, 73728, reports the size of what?

drwxr-xr-x 3 root root 73728 Dec 26 08:39 /usr/bin/ <=== This directory file on an ext4 filesystem is listed in long format (ls -ld). The value of the fifth field, 73728, reports the size of what?

• The exact size of the directory file, in bytes.
• The disk usage, in blocks, of the directory and all of its subdirectories.
• The size in bytes of the total blocks in use by the directory file. [ (bytes/block) * blocks ]
• The disk usage, in blocks, of the top level of the directory. 

 

EXPLANATION

A directory file contains a list of names and corresponding inodes. 
A newly created directory file on an ext4 filesystem will have only 2 entries, dot "." and dot dot ".."  
The size of the new directory file will be 4096 bytes.  As additional entries are made to the directory, the reported size will remain at 4096 until additional bytes are required for the next directory entry.  At that point, additional blocks will be allocated to the directory and the reported directory file size will increase.
As directory entries are removed, the blocks already allocated to the directory file do not decrease, but allocated blocks are freed for future use by new entries in the directory.
https://unix.stackexchange.com/questions/234065/why-size-reporting-for-directories-is-different-than-other-files#
https://superuser.com/questions/142893/why-is-the-size-of-a-directory-always-4096-bytes-in-unix/1428...
http://www.linfo.org/directory.html
Note that when the same "ls" command is used on a regular file, the size field will report the actual file size in bytes, which is stored in the inode.  The " -s " option to "ls" will report allocated blocks, in addition to actual file size.

SOURCE

https://superuser.com/questions/142893/why-is-the-size-of-a-directory-always-4096-bytes-in-unix/142895

Read More

What is the unique identifier for network hardware called?

What is the unique identifier for network hardware called?

• Gettysburg address
• MAC address
• IP address
• Network address 

 

EXPLANATION

A media access control (MAC) address is a unique identifier associated with network hardware for communicating on the physical network.
A media access control address of a device is a unique identifier assigned to a network interface controller for communications at the data link layer of a network segment. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet and Wi-Fi. In this context, MAC addresses are used in the medium access control protocol sublayer.

Read More

One of your users can receive mail but can't send any. You notice that the "Type of Outgoing Mail Server" field is blank in the mail application. Which of the following protocols will you most likely enter as a value in this field?

One of your users can receive mail but can't send any. You notice that the "Type of Outgoing Mail Server" field is blank in the mail application. Which of the following protocols will you most likely enter as a value in this field?

• IMAP
• POP3
• NMP
• SMTP

EXPLANATION

 

POP In computing, the Post Office Protocol is an application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a server in an Internet Protocol network. POP version 3 is the most recent level of development in common use. POP has largely been superseded by the Internet Message Access Protocol.

 

IMAP In computing, the Internet Message Access Protocol is an Internet standard protocol used by email clients to retrieve email messages from a mail server over a TCP/IP connection. IMAP is defined by RFC 3501.

  SMTP is used to send email and is a protocol within the TCP/IP protocol suite. POP3 and IMAP are email retrieval protocols, not protocols for sending email.

 

Read More

Linux and Unix systems typically track 3 timestamps in file inodes: atime, ctime, and mtime. The "a" in atime means access. The "m" in mtime means modify. What does the "c" in ctime mean?

Linux and Unix systems typically track 3 timestamps in file inodes: atime, ctime, and mtime. The "a" in atime means access. The "m" in mtime means modify. What does the "c" in ctime mean?

• cache
• create
•  change
• copy-on-write 

 

EXPLANATION

"c" in ctime means change.  Specifically, a change to the inode's status, eg, permissions, ownership, link count, file size, etc.
http://man7.org/linux/man-pages/man7/inode.7.html
"Last status change timestamp (ctime) stat.st_ctime; statx.stx_ctime"

http://www.linux-mag.com/id/8658/
"Timestamps telling when the inode itself was last change (ctime, changing time), the file content was last modified (mtime or modification time), and when the file was last accessed (atime or access time)"

SOURCE

http://man7.org/linux/man-pages/man7/inode.7.html

Read More

When it comes to SNMP technology, what is the range of the "Counter32" parameter?

When it comes to SNMP technology, what is the range of the "Counter32" parameter?

• 0 to 4294967295
• 0 to 1099511627776
• 32 to 272
• -100 to 100 

 

EXPLANATION

The Counter32 class allows all the functionality of unsigned integers but is recognized as a distinct SMI type, which specifies a value that represents a count.
The range is 0 to 4294967295

https://www.webnms.com/snmp/help/snmpapi/snmpv3/using_mibs_in_applns/countr32.html

Read More

What is the fastest back-end database for OpenLDAP ?

What is the fastest back-end database for OpenLDAP ?

• hdb
• sql
• mdb
• bdb 

 

EXPLANATION

• A file with the MDB file extension is a Microsoft Access Database file that literally stands for Microsoft Database. ...
• MDB files contain database queries, tables, and more that can be used to link to and store data from other files, like XML and HTML, and applications, like Excel and SharePoint.

 

http://www.openldap.org/pub/hyc/mdm-paper.pdf

SOURCE

http://www.openldap.org/pub/hyc/mdm-paper.pdf

Read More

Which of these is NOT a use case of Microsoft Azure Stack?

Which of these is NOT a use case of Microsoft Azure Stack?

• Update and extend legacy applications with modern Azure services on-premise
• Address latency and connectivity requirements for edge and disconnected solutions
• Develop applications and deploy in Azure or on-premises to meet regulatory and policy requirements
• The next-gen Hyper-V platform for you to migrate your current workloads on your existing hardware 

EXPLANATION

If you answered "next-gen Hyper-V platform for you to migrate..." then yes you're correct - that is NOT the intended use case of Microsoft Azure Stack.  Microsoft Windows Server Software Defined (WSSD)
is a better solution to implement virtualization in scale within your datacenter.   Azure Stack's three primary use cases can be found at the link provided to learn more.

SOURCE

https://azure.microsoft.com/en-us/overview/azure-stack/

Read More