Most Popular

1500 questions
72
votes
2 answers

Why is it so difficult to upgrade between major versions of Red Hat and CentOS?

"Can we upgrade our existing production EL5 servers to EL6?" A simple-sounding request from two customers with completely different environments prompted my usual best-practices answer of "yes, but it will require a coordinated rebuild of all of…
ewwhite
  • 201,205
72
votes
10 answers

Convert from P7B to PEM via OpenSSL

On Ubuntu, I cannot convert certificate using openssl successfully. vagrant@dev:/vagrant/keys$ openssl pkcs7 -print_certs -in a.p7b -out a.cer unable to load PKCS7 object :PEM routines:PEM_read_bio:no start line:pem_lib.c:696:Expecting:…
72
votes
9 answers

Unknown/unsupported storage engine: InnoDB | MySQL Ubuntu

I recently upgraded from the previous LTS Ubuntu to Precise and now mysql refuses to start. It complains of the following when I attempt to start it: ╰$ sudo service mysql restart stop: Unknown instance: start: Job failed to start And this shows in…
Garrett
  • 853
72
votes
4 answers

Is there a difference between how two ampersands and a semi-colon operate in bash?

If I wanted to run two separate commands on one line, I could do this: cd /home; ls -al or this: cd /home && ls -al And I get the same results. However, what is going on in the background with these two methods? What is the functional difference…
Sean P
  • 737
72
votes
3 answers

crontab running as a specific user

I need to run a script daily. The script should be run as a specific user (ex. user1) not as root. So I put the cron file at /etc/cron.d and put the user name in the line (2nd column). But it gives an error saying that the command is not found. I…
Sam Kong
  • 993
72
votes
20 answers

How to create an SHA-512 hashed password for shadow?

The previous SF questions I've seen have lead to answers that produce MD5 hashed password. Does anyone have a suggestion on to produce an SHA-512 hashed password? I'd prefer a one liner instead of a script but, if a script is the only solution,…
Belmin Fernandez
  • 11,039
  • 28
  • 89
  • 150
72
votes
9 answers

How do I determine the block size of an ext3 partition on Linux?

How do I determine the block size of an ext3 partition on Linux?
mike
  • 4,123
72
votes
8 answers

Is there a way to redirect output to a file without buffering on unix/linux?

I have a long running batch process that outputs some debug and process information to stdout. If I just run from a terminal I can keep track of 'where it is' but then the data gets too much and scrolls off the screen. If I redirect to output to a…
72
votes
4 answers

What is the difference between iisreset, recycle, refresh and restart?

In IIS7, there are numerous things you can do that seem to restart the website. I am unclear about exactly how they are all related. run iisreset from the command line refresh a website recycle an app pool restart a website Can someone explain…
72
votes
3 answers

How do I enable non-free packages on Debian?

How can I enable non-free packages on Debian? I want to install Sun's Java JDK but it's not available to me.
Quiffner
  • 723
  • 1
  • 5
  • 4
72
votes
2 answers

How to restart rsyslog daemon on ubuntu

how can i restart rsyslog or rsyslogd on ubuntu 10 root@terminator:/etc/init.d# service rsyslog status rsyslog stop/waiting root@terminator:/etc/init.d# service rsyslog stop stop: Unknown instance: root@terminator:/etc/init.d# service rsyslog…
John
72
votes
4 answers

Get a list of SQL Server Agent Jobs

I've got an extensive selection of these to add to a spreadsheet and don't want to go through by hand. What it the T-SQL command(s) to generate a list of SQL Server Agent Jobs?
alimack
  • 1,033
72
votes
11 answers

Linux: How to use a file as input and output at the same time?

I've just run the following in bash: uniq .bash_history > .bash_history and my history file ended up completely empty. I guess I need a way to read the whole file before writing to it. How is that done? PS: I obviously thought of using a temporary…
MilliaLover
  • 987
  • 1
  • 8
  • 8
72
votes
1 answer

How long does it take for DNS records to propagate?

This is a Canonical Question about DNS Propagation How long does it take for an the various types of records to propagate? Do some propagate faster than others? Why does it take time for DNS records to propagate and how does it work?
user38535
72
votes
4 answers

Redirect URL within Apache VirtualHost?

I have a dedicated server with Apache, on which I've set up some VirtualHosts. I've set up one to handle the www domain as well as the non-www domain. My VH .conf file for the www: DocumentRoot /var/www/site ServerName…