Greatest Hits

6
votes
1answer
49k views

Deploying VM from vmdk / vmx file

I have a vmdk file and vmx file (and all the other files from someone elses datastore) copied onto my own data store. If I try to deploy from the vmx file, I get a vm with the name "unknown # ...
37
votes
10answers
90k views

Running a cron job manually and immediately

(I have already read How can I test a new cron script ?.) I have a specific problem (cron job doesn't appear to run, or run properly), but the issue is general: I'd like to debug scripts that are ...
48
votes
6answers
81k views

How to send emails and avoid them being classified as spam?

This is a canonical question about how to handle email sent from your server being misclassified as spam. For additional information you may find these similar questions helpful: Best ...
11
votes
5answers
77k views

How do I configure proxy settings for LOCAL SYSTEM?

If I edit Proxy Settings through the Control Panel, the settings are stored in HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ProxyEnable and ...\ProxyServer. These ...
4
votes
4answers
29k views

How to export a detailed list of Active Directory users' “Member of” tab?

I am currently in the process of restructuring the Active Directory user list of the company I'm working for, and the person who did it did an awful job, and is of course, not working here anymore. ...
11
votes
5answers
119k views

How do I increase the maximum number of concurrent remote connections in Windows Server 2003?

I am trying to allow more than the default of 2 concurrent remote connections to a server running Windows Server 2003. Background: I went to "Start" => "Administration Tools" => "Terminal Services ...
71
votes
2answers
105k views

How to Configure Windows Machine to Allow File Sharing with DNS Alias

What process is necessary to configure a Windows environement to allow me to use DNS CNAME to reference servers? I want to do this so that I can name my servers something like SRV001, but still have ...
65
votes
8answers
133k views

What limits the maximum number of connections on a Linux server?

What kernel parameter or other settings control the maximum number of TCP sockets that can be open on a Linux server? What are the tradeoffs of allowing more connections? I noticed while load testing ...
62
votes
4answers
85k views

How can I see Time-To-Live (TTL) for a DNS record?

I would like to see the Time-To-Live (TTL) value for a CNAME record. I have access to dig (on Apple Mac OS X), which gives me an answer like this: % dig host.example.gov <*SNIP*> ;; ANSWER ...
26
votes
4answers
54k views

how to restart/clear memcache without restarting the whole web server?

/opt/eduserver/eduserver gives me options: Usage: /opt/eduserver/eduserver ...
6
votes
6answers
84k views

How do I completely remove MySQL from a linux installation?

I was surprised to find that one of my privileged users installed MySQL on a linux box. The server (mysqld) is running and doing nothing. My skills are all in Oracle, so I am unfamiliar with how to ...
48
votes
12answers
25k views

How can I run arbitrarily complex command using sudo over ssh?

I have a system that I can only log in to under my username (myuser), but I need to run commands as other user (scriptuser). So far, I have come up with the following to run the commands I need: ssh ...
23
votes
3answers
6k views

What kinds of security vulnerabilities does providing DNSSEC expose?

I was planning to sign my DNS zone with DNSSEC. My zone, the registrar and my DNS server (BIND9) all support DNSSEC. The only one who doesn't support DNSSEC is my secondary nameserver provider (namely ...
5
votes
7answers
105k views

How do I remove a driver completely on a Windows XP client machine?

I have a client (XP SP3) machine where newer drivers have been installed. Unfortunately while these (audio) drivers fixed mic boost, they have introduced problems such as no input working and ...
29
votes
6answers
72k views

How to remove strict RSA key checking in SSH and what's the problem here?

I have a Linux server that whenever I connect it shows me the message that changed the SSH host key: $ ssh root@host1 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: ...
5
votes
3answers
71k views

Email bounce back 550 5.1.1 recipient rejected

A client recently switched to Exchange Server / Outlook for their email. Since then emails from my company to any email address at their company bounce back from the System Administrator with this ...
7
votes
3answers
45k views

Difference between 2Rx4 vs 2Rx8 RAM

My IT provider is convincing me there is no difference between a 2Rx4 and a 2Rx8 RAM. A little digging around informed me that x4 means 4 bits on a chip vs x8 means 8 bits. Which is good, but what ...
92
60
votes
12answers
94k views

Subversion error: (405 Method Not Allowed) in response to MKCOL

I am getting the following error while trying to commit a new directory addition. svn: Commit failed (details follow): svn: Server sent unexpected return value (405 Method Not Allowed) in response to ...
74
29
votes
2answers
84k views

How do I view the details of a digital certificate .cer file?

I am using Windows and have been given a .cer file. How can I view the details of it?
65
votes
1answer
77k views

InnoDB: Error: log file ./ib_logfile0 is of different size

I just added the following lines in /etc/mysql/my.cnf after I converted one database to use InnoDB engine. innodb_buffer_pool_size = 2560M innodb_log_file_size = 256M innodb_log_buffer_size = 8M ...
52
votes
7answers
67k views

mysqldump to a tar.gz

Usually after dumping a MySQL database with mysqldump command I immediately tar/gzip the resultant file. I'm looking for a way to do this in one command: So from this: mysqldump dbname -u root -p ...
39
votes
8answers
71k views

How do I check the postfix queue size?

What's the postfix equivalent to sendmail -bp?
85
124
votes
2answers
50k views

How can I see which flags Nginx was compiled with?

How can I check what modules have been added to an nginx installation?
89
9
votes
2answers
22k views

500 error on fresh install of IIS and PHP

When attempting to run a PHP file on Windows server 2012 and IIS, I keep getting a 500 error. I cannot find any detailed logs or anything. However, when going to PHP Manager for IIS and click check ...
73
25
votes
5answers
71k views

High load average, low CPU usage - why?

We're seeing huge performance problems on a web application and we're trying to find the bottleneck. I am not a sysadmin so there is some stuff I don't quite get. Some basic investigation shows the ...
5
votes
7answers
94k views

Enforcing lock screen after idle time via GPO

I run a network of computers and I would like enforce a GPO which locks the screen after a predefined idle time. I can't find this setting, I can only find a screen saver idle time setting, how can I ...
16
votes
8answers
32k views

How do I disable SSLv3 support in Apache Tomcat?

I am trying to reconfigure my Apache Tomcat server to only use TLSv1. However, it is still falling back to SSLv3 using certain browsers. I setup the <connector> tag with the following settings: ...
108
votes
4answers
148k views

FreeBSD performance tuning: Sysctl parameter, loader.conf, kernel

I wanted to share knowledge of tuning FreeBSD via sysctl.conf / loader.conf / KENCONF / etc. It was initially based on Igor Sysoev's (author of nginx) presentation about FreeBSD tuning up to ...
17
votes
4answers
87k views

What causes duplicate ACK records?

We're reviewing Wireshark captures from a few client machines that are showing multiple duplicate ACK records which then triggers retransmit and out-of-sequence packets. These are shown in the ...
21
votes
3answers
41k views

apt-get update getting 404 on debian lenny

Here is my /etc/apt/sources.list ###### Debian Main Repos deb http://ftp.us.debian.org/debian/ lenny main contrib non-free ###### Debian Update Repos deb http://security.debian.org/ lenny/updates ...
37
votes
5answers
71k views

How do I verify the speed of my NIC?

I just installed a new gigabit network interface card (NIC) in Linux. How do I tell if it is really set to gigabit speeds? I see ethtool has an option to set the speed, but I can't seem to figure ...
21
votes
5answers
81k views

How do I list all users with root?

On a linux box, how do I list all users that have root priveleges (and even better, all users in general along with if they have root or not)?
11
votes
11answers
68k views

IIS/SMTP - emails are stuck in mailroot/Queue

I'm trying to send e-mails via SMTP within the IIS pickup directory. Unfortunately the e-mails are just going into the mailroot/queue folder and stay there. They never actually get sent. Does ...
82
199
votes
11answers
64k views

Can I nohup/screen an already-started process?

I'm doing some test-runs of long-running data migration scripts, over SSH. Let's say I start running a script around 4 PM; now, 6 PM rolls around, and I'm cursing myself for not doing this all in ...
17
votes
2answers
51k views

How does ServerName and ServerAlias work?

It's the following part of a virtual host config that I need further clarification on: <VirtualHost *:80> # Admin email, Server Name (domain name), and any aliases ServerAdmin ...
63
votes
7answers
104k views

Apache 2 startup warning: NameVirtualHost *:80 has no VirtualHosts

When my Ubuntu Apache server (Apache 2) starts up I get a warning message that reads: [warn] NameVirtualHost *:80 has no VirtualHosts However, the web server is working fine. What might I have ...
11
votes
11answers
76k views

Network Printers Offline (but not really)

I have two Ricoh printers/copiers setup for IP printing in the office. Before this week there were no problems printing to them. Now a handful of them (All running Vista, not sure if it is every Vista ...
45
votes
3answers
60k views

How to override/update a symlink?

I am trying to use symbolic links. I did some reading and found the following commands: Creation -> ln -s {/path/to/file-name} {link-name} Update -> ln -sfn {/path/to/file-name} {link-name} ...
18
votes
12answers
69k views

How to recover from “Too many Authentication Failures for user root”

I've done several attempts to establish SSH-connecton for user root@host using putty terminal. While doing so I specified wrong credentials several times and after that I've specified them correctly, ...
84
52
votes
7answers
81k views

Should I use tap or tun for openvpn?

What are the differences between using dev tap and dev tun for openvpn? I know the different modes cannot inter-operate. What is the technical differences, other then just layer 2 vs 3 operation. ...
5
votes
2answers
43k views

How to completely wipe WSUS and start again

Anyone know of a way to completely wipe WSUS of updates and start again? It seems as if I have loads of language packs and assorted rubbish in the list which we do not need. Having now removed all ...
72
9
votes
2answers
44k views

When an Excel file is locked on a network share, how does it know who locked the file?

We are using Excel 2010 and sometimes users are working from a network share. When a user on the network opens the file in Excel, the file is locked for editing - this is the expected behavior. When ...
30
votes
2answers
77k views

How do I configure LDAP on Centos 6 for user authentication in the most secure and correct way?

During the last couple of days I have been using a lot of F-words, while browsing Internet for good documentation about how to setup an LDAP-server. So far I have found none, but plenty that are less ...
3
votes
2answers
28k views

Renewing SBS2011 Exchange Self-Signed Certificate w/o changing home page in IE?

On a previous server when we used the built in SBS wizard to renew the certificate it worked, however it reset all of the computers on the domain's IE home page to companyweb. Is there a way to do ...
14
votes
4answers
62k views

How to save and exit crontab -e?

How to save and exit crontab -e? i tried every method listed here and none works, i have a centos 5, vi comes by default with yum and i installed nano Solved just changed the default editor export ...
25
votes
6answers
57k views

How can I list my open ports on Debian?

What is the command to display a list of open ports on a Debian server? I tried netstat -a | egrep 'Proto|LISTEN' but I would like something more specific that actually lists the port number.
93
votes
7answers
78k views

Can anyone explain precisely what IOWait is?

As much as I have read about iowait, it is still mystery to me. I know it's the time spent by the CPU waiting for a IO operations to complete, but what kind of IO operations precisely? What I am also ...
78
13
votes
5answers
108k views

Where are my Tomcat Logs?

I installed Tomcat6 on a Ubuntu 9.04 server using apt-get install tomcat6. I uploaded a WAR using the manager interface and tried to start the application but get a pretty generic error on the Web ...
36
votes
7answers
130k views

Where to check log of sendmail?

I can't send out emails, need to look into the logs, but where is the log?
26
votes
6answers
73k views

what are named and default instance?

what are named and default instance? what is the difference between them? why they are used?