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Wednesday, May 15, 2019

What is the maximum RAM that can be used by a virtual machine in Vmware Vsphere 6.5?

What is the maximum RAM that can be used by a virtual machine in Vmware Vsphere 6.5?

  • 2 TB
  • 4 TB
  • 1 TB
  • 6 TB

What is the maximum RAM that can be used by a virtual machine in Vmware Vsphere 6.5?

EXPLANATION

The maximum memory for each virtual machine has increased from 4 TB in Vsphere 60o to 6 TB in Vshere 6.5.

Platform Services Controller Maximums
Powered-on VMs per vCenter Server2500010000
RAM per host12TB6TB *some exceptions
RAM per VM6128GB4080GB
Registered VMs per vCenter Server3500015000

SOURCE

https://www.vmware.com/pdf/vsphere6/r65/vsphere-65-configuration-maximums.pdf

 

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Tuesday, May 14, 2019

A single Unified Threat Management (UTM) appliance is not capable of which of the following?

A single Unified Threat Management (UTM) appliance is not capable of which of the following?

  • Firewall
  • Anti-virus capabilities
  • Load balancing
  • High availability 


EXPLANATION

Unified Threat Management (UTM)

It started in 2003 when vendors started launching “all-in-one” security products and called them UTMs. Since then the term remains in use.
Nowadays, UTMs is a common thing that incorporates many security services. The need to deploy multiple separate devices is no more required.

Difference UTM Firewall & UTM Appliance

Firewalls come in the form of a software-based or as a hardware-based network security tool to deliver protection against security threats. The basic function of any firewall is to follow a set of standard rules. It checks the incoming and outgoing data flow with the archived records to check if the content is malicious or free of malware. If they are found malware free, they are permitted to pass through the network for the required user to access the data.
However, if the data is found malicious, the firewall filters off the malware from the data content. The default firewall is installed in almost all the PCs which is mainly software-based firewalls and are implemented to protect against the security threats. Sometimes firewalls come attached to different types of routers to provide protection. Hardware-based firewalls are also known to perform routing functions.

 

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The linux admin inadvertently changed permissions on /usr/bin/ls, a 64-bit ELF executable, from 755 to 511. Which users are now authorized to execute "ls" from the command line?

The linux admin inadvertently changed permissions on /usr/bin/ls, a 64-bit ELF executable, from 755 to 511. Which users are now authorized to execute "ls" from the command line?

  • Only the owner and members of the group associated with the file.
  • User root, and only user root.
  • All users.
  • The owner, and only the owner. 
The linux admin inadvertently changed permissions on /usr/bin/ls, a 64-bit ELF executable, from 755 to 511. Which users are now authorized to execute "ls" from the command line?

EXPLANATION

How to change your file to 511 or -r-x--x--x using chmod

Chmod is a well known command line utility, that's used to manage file permissions on MacOS, Linux and other Unix like operating systems. While there are multiple ways to use chmod, on this site, we have chosen to focus exclusively on using chmod with Octal Notation. The following examples illustrate exactly how to change your desired file to permissions matching "511 or -r-x--x--x" using the command line and chmod. If you're lost on how to manually manage file permissions, see our guide - How Do I Change File Permissions Using chmod?

From your terminal run the following command, within a directory containing the file you wish to change permissions on. In this case the filename is "yourfile.txt"
$ chmod 511 yourfile.txt
Confirming your change, your file's symbolic permissions should now be "-r-x--x--x"
$ ls -l

# your output will be similar to the following
-r-x--x--x 14 root root 4096 Jun 22 07:36 yourfile.txt

 

/usr/bin/ls is an ELF 64-bit executable and "r"ead access in not required by the kernel to execute it.
$  ## Determine the current user, group, and supplementary groups
$ id
uid=1001(terry) gid=100(users) groups=100(users),600(ftpaccess),601(terry),1001(mktg),1002(acctg),1004(family)

$ ## Determine the file type of /usr/bin/ls
$ file /usr/bin/ls  
/usr/bin/ls: executable, regular file, no read permission

$ ## Show the permissions, owner, group of /usr/bin/ls 
$ ls -l /usr/bin/ls
-r-x--x--x 1 root root 110272 Mar 17  2014 /usr/bin/ls

$ ##  Try to run the ls command as user terry, group users
$ ls -l /tmp/Test
total 12
drwxr-xr-x 3 root root 4096 Aug 11  2015 a
-rw-r--r-- 1 root root 8003 Feb 22  2016 known_hosts
Note that if a file is a shell script, read permission is required, in addition to execute, because the user's shell must be able to read a script in order to run it.  This is not the case with binary executable files, where only the "x" bit needs set.
Aside:  In the case of a shell script, a script file with read, but not execute permission, can be passed to the shell as an argument to be run, eg.  "bash  script.sh"
See "Execute Permission of a file" at http://www.grymoire.com/Unix/Permissions.html#TOC

SOURCE

http://www.grymoire.com/Unix/Permissions.html#TOC
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When data traveling across a network fails to reach its destination, this is known as which of the following:

When data traveling across a network fails to reach its destination, this is known as which of the following:

  • Packet loss
  • Missed connections
  • Delayed package
  • Missed delivery 

When data traveling across a network fails to reach its destination, this is known as which of the following:

EXPLANATION

Packet loss is typically caused by network congestion and is measured as a percentage of packets lost with respect to packets sent.

The other three are not really network related.

See: https://en.wikipedia.org/wiki/Packet_loss for more details on packet lossed.

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Monday, May 13, 2019

Which port does the AWS Route 53 service use?

Which port does the AWS Route 53 service use?

  • 76
  • 53
  • 109
  • 8080 

 
Which port does the AWS Route 53 service use?

EXPLANATION

Amazon Route 53 provides highly available and scalable Domain Name System (DNS), domain name registration, and health-checking web services. It is designed to give developers and businesses an extremely reliable and cost effective way to route end users to Internet
applications by translating names like example.com into the numeric IP addresses, such as 192.0.2.1, that computers use to connect to each other. The name is a reference to TCP or UDP port 53, 

SOURCE

https://en.wikipedia.org/wiki/Amazon_Route_53
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Friday, May 10, 2019

In respect to GDPR; when personal data has been collected with consent can the consenting party later request this data be deleted

In respect to GDPR; when personal data has been collected with consent can the consenting party later request this data be deleted

  • Yes, chapt 3. art 17. This is the "right to be forgotten"
  • No, Data obtained with consent can't be deleted
  • No, Data needed by a process can't be deleted
  • No, Data can't be deleted 

 
In respect to GDPR; when personal data has been collected with consent can the consenting party later request this data be deleted

EXPLANATION

The data subject shall have the right to obtain from the controller the erasure of personal data concerning him or her without undue delay and the controller shall have the obligation to erase personal data without undue delay where one of the following grounds applies:
  • The personal data are no longer necessary in relation to the purposes for which they were collected or otherwise processed;
  • The data subject withdraws consent on which the processing is based according to point (a) of Article 6(1), or point (a) of Article 9(2), and where there is no other legal ground for the processing;
  • The data subject objects to the processing pursuant to Article 21(1) and there are no overriding legitimate grounds for the processing, or the data subject objects to the processing pursuant to Article 21(2);
  • The personal data have been unlawfully processed;
  • The personal data have to be erased for compliance with a legal obligation in Union or Member State law to which the controller is subject;
  • The personal data have been collected in relation to the offer of information society services referred to in Article 8(1).

SOURCE

https://gdpr-info.eu/art-17-gdpr/
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Wednesday, May 8, 2019

In SQL, which type of JOIN returns all rows from at least one of the tables mentioned from the FROM clause, providing those rows meet any WHERE or HAVING search conditions?

In SQL, which type of JOIN returns all rows from at least one of the tables mentioned from the FROM clause, providing those rows meet any WHERE or HAVING search conditions?

  • Table Join
  • Outer Join
  • Comparison Join
  • Inner Join 

 
In SQL, which type of JOIN returns all rows from at least one of the tables mentioned from the FROM clause, providing those rows meet any WHERE or HAVING search conditions?

EXPLANATION

Inner joins return rows only when there is at least one row from both tables that matches the join condition. Inner joins eliminate the rows that do not match with a row from the other table. Outer joins, however, return all rows from at least one of the tables or views mentioned in
the FROM clause, as long as those rows meet any WHERE or HAVING search conditions. All rows are retrieved from the left table referenced with a left outer join, and all rows from the right table referenced in a right outer join. All rows from both tables are returned in a full outer join.

SOURCE

https://technet.microsoft.com/en-us/library/ms187518(v=sql.105).aspx
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