Greatest Hits

34
votes
4answers
48k views

How to change sshd port on Mac OS X?

I want to change which port sshd uses on a Mac server. For example, let's say from port 22 to port 32. Editing /etc/sshd_config does not seem to work. Does anyone know how to change it? I'd prefer ...
10
votes
2answers
66k views

How to test a LDAP connection from a client

How to check the LDAP connection from a client to server. I'm working on the LDAP authentication and this client desktop needs to authenticate via a LDAP server. I can SSH to the LDAP server using ...
182
votes
11answers
58k 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 ...
39
votes
6answers
69k 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 ...
26
votes
9answers
66k views

Windows server last reboot time

How can I find a Windows server's last reboot time, apart from 'net statistics server/workstation'?
67
7
votes
11answers
55k views

Exchange 2010 and Outlook 2010 requesting password every time it starts

I have one Exchange 2010 server which is fully updated, the clients are running Outlook 2010 but some users are getting a prompt for credentials every time they open Outlook. I have checked for ...
52
votes
5answers
91k views

How to start/stop/restart launchd services from the command line?

How do I restart, say for example my httpd or afpd, running any Mac OS X >= 10.5 (Leopard-), without having to use the GUI and go to System Preferences -> Sharing and unchecking/checking "Web ...
36
votes
4answers
48k views

How do I grep through binary files that look like text?

I have binary files that should be text (they're exported logs), but I can't open it with less (it looks ugly - it looks like a binary file). I found that I could open it with vi and I can cat it ...
55
votes
5answers
47k views

How to run a command multiple times?

Is there a way to run a command (e.g. ps aux|grep someprocess) for n times? Something like: run -n 10 'ps aux|grep someprocess' I want to use it interactively, please do not post scripts. ...
73
38
votes
5answers
84k views

How do I grant start/stop/restart permissions on a service to an arbitrary user or group on a non-domain-member server?

We have a suite of Windows Services running on our servers which perform a bunch of automated tasks independently of one another, with the exception of one service which looks after the other ...
76
votes
1answer
52k views

What is a challenge password?

I'm setting up SSL on an Ubuntu server. One of fields it asks for as part of setting up the CSR is a "challenge password". What is that? The default is blank. Do I need to enter one?
69
0
votes
3answers
29k views

phpmyadmin “Forbidden: You don't have permission to access /phpmyadmin on this server.”

I need to modify the file /etc/httpd/conf.d/phpMyAdmin.conf in order to allow remote users (not only localhost) to login # phpMyAdmin - Web based MySQL browser written in php # # Allows only ...
17
votes
7answers
72k views

Nginx + php-fpm “504 Gateway Time-out” error with almost zero load (on a test-server)

After debugging for 6-hours - I am giving this up :| We have a nginx+php-fpm+mysql in LAN with almost 100 wordpress (created and used by different designers/developers all working on test wordpres ...
26
votes
1answer
55k views

How do I change the privileges for MySQL user that is already created?

I understand how to create a new user with privileges, but what is the correct way to change privileges for users that are already created? We are running a DB audit and some of the users have way ...
77
55
votes
8answers
116k 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 ...
34
votes
9answers
54k views

How do I get apt-get to ignore some dependencies?

How do I make apt-get ignore some dependencies? For example, I wanted to install mailx so I can use it to send email from cron scripts/report-generating tools. However, installing mailx also installs ...
15
votes
1answer
81k views

Where/how does Windows store the data in the event logs?

We run some financial systems that log error messages to the system logs. I need to find out if we can clean these error messages from a PCI DSS point of view. I am specificaly interested in the ...
21
votes
4answers
75k views

connect() failed (111: Connection refused) while connecting to upstream

I'm experiencing 502 gateway errors when accessing a PHP file in a directory (http://domain.com/dev/index.php), the logs simply says this: 2011/09/30 23:47:54 [error] 31160#0: *35 connect() failed ...
7
votes
1answer
69k views

TCP/IP ports necessary for CIFS/SMB operation

If I want to allow Windows networked drives between two firewalled computers, do I need to open ports 137-139, or is port 445 sufficient? I have to submit a form and get approval to open firewall ...
17
votes
4answers
56k views

Prevent Windows Server 2012 from forcing a reboot after updates

I have a domain controller with Windows Server 2012 on it. After updates, the server does not reboot immediately. However if I remote into the server I will be presented with a countdown for a reboot. ...
11
votes
4answers
52k views

How to allow active directory users to remote desktop in?

This is my first time setting up or even using active directory. I set it up, and added the computers(Actually VMs in Hyper V) to the active directory, and if if I use hyper-V to connect to the VMs, ...
10
votes
5answers
18k 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: ...
16
votes
3answers
80k views

For Loop counting from 1 to n in a windows bat script

I need to run a windows command n times within a bat script file. I know how to do this in various programming languages but cannot manage to get it right on the windows command line :-( I would ...
55
votes
5answers
59k views

How to setup passwordless `sudo` on Linux?

How can passwordless sudo access be setup on either RHEL (Fedora, CentOS, etc) or Ubuntu distributions? (If it's the same across distros, that's even better!) Setting: personal and/or lab/training ...
15
votes
4answers
75k views

What's the maximum number of wifi connections for a single WiFi router?

We've got a Draytek 2829VN Wifi router and I'm wondering how many concurrent connections I should expect a router of this kind to cope with? We are looking to connect 60 iPads! I'd also be ...
18
votes
7answers
68k views

What is the value of JAVA_HOME for CentOS?

I have install java through yum on CentOS, however another java programme needs to know what the JAVA_HOME environmental variable is. I know all about setting environmental variables, but what do I ...
22
votes
9answers
110k views

Is there a way to clone an existing VM on an ESXi server without having to re-import it?

I have imported a VM into an ESXi server using the VMware "Converter stand alone utility". However, this process is a little tedious. Since I eventually want several copies of this VM (or, to be ...
47
votes
8answers
62k views

How can I monitor hard disk load on linux

Is there a good command line utility to monitor hard disk load on linux? Something like top but then monitoring disk activity i.s.o. cpu usage. More specifically, I suspect that for some (heavy load) ...
16
votes
9answers
73k views

How do I make Linux recognize a new SATA /dev/sda drive I hot swapped in without rebooting?

Hot swapping out a failed SATA /dev/sda drive worked fine, but when I went to swap in a new drive, it wasn't recognized: [root@fs-2 ~]# tail -18 /var/log/messages May 5 16:54:35 fs-2 kernel: ata1: ...
40
votes
3answers
63k views

How can I connect to a Windows server using a Command Line Interface? (CLI)

Especially with the option to install Server Core in Server 2008 and above, connecting to Windows servers over a CLI is increasingly useful ability, if not one that's very widespread amongst Windows ...
56
votes
1answer
56k views

How do I add Access-Control-Allow-Origin in NGINX?

How do I set the Access-Control-Allow-Origin header so I can use web-fonts from my subdomain on my main domain? Notes: You'll find examples of this and other headers for most HTTP servers in the ...
69
19
votes
3answers
43k views

how do you create an ssh key for another user?

I'm trying to create an ssh key for another user. I'm logged in as root. Can I just edit the files generated by ssh-keygen and change root to the user I want?
17
votes
3answers
55k views

View Shutdown Event Tracker logs under Windows Server 2008 R2

I'm trying to view the Shutdown Event Tracker logs in the Event Viewer, on windows server 2008 r8, but I can't find the messages that I supplied when previously restart the server. Where in the Event ...
9
votes
1answer
66k views

What is a SQL Server instance?

When I install SQL Server 2008 Express in prompts me to create an instance and aborts if I don't. Then I see that information in an entry in Sql Server Configuration Manager on SQL Server Services. ...
9
votes
7answers
75k views

“Error 1067: The process terminated unexpectedly” when trying to install MySQL on Win7 x64

I've run into a brick wall trying to install MySQL v5.5 on my machine. My PC is Windows 7 x64, Enterprise edition. MySQL installs fine, but when I run the "MySQL Instance Configuration Wizard", it ...
6
votes
7answers
48k views

What is an edge server / router / device?

What is an edge server? We see some references to them, but we never see a definition.
7
votes
4answers
80k views

How to check if hardware RAID is configured?

I have several servers running Windows 2008 and Red Hat 5 that are capable of hardware RAID. How do I check that hardware RAID is configured?
37
votes
5answers
45k views

When does /tmp get cleared?

I'm taking to putting various files in /tmp, and I wondered what the rules on deleting them are? I'm imagining it's different for different distributions, and I'm particularly interested in Ubuntu ...
15
votes
4answers
73k 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 ...
23
votes
6answers
60k views

what are named and default instance?

what are named and default instance? what is the difference between them? why they are used?
29
votes
8answers
42k views

How do I update a CentOS server's time from an authoritative time server?

I have CentOS machine and each time I've noticed that the server loses correct time after a while. It is usually behind by several minutes after time passes from having manually set the correct time. ...
102
votes
2answers
38k views

How can I see which flags Nginx was compiled with?

How can I check what modules have been added to an nginx installation?
76
2
votes
3answers
33k views

SCP copy windows local file to linux remote folder

How to get a file from my path d:/test.txt and copy it to /etc/var/test/test.txt I've tried this: scp d:/test.txt /etc/var/test/test.txt but that didn't worked, how to set the hard disk from where ...
10
votes
4answers
60k 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 ...
39
votes
10answers
14k 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 ...
45
votes
7answers
67k 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. ...
47
votes
7answers
56k 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 ...
28
votes
3answers
11k views

How can I check /dev/xvda1?

On login to EC2 (Ubuntu) instance, I see *** /dev/xvda1 should be checked for errors *** I can't fsck /dev/xvda1 because it is mounted, and sudo umount /dev/xvda1 fails because it is in use. lsof ...
26
votes
5answers
84k views

What is a system state backup for?

The windows backup utility comes with an option to backup the system-state. What is this for? Has it a real utility? Can I recover that windows on another machine?
33
votes
7answers
58k views

How do I check the postfix queue size?

What's the postfix equivalent to sendmail -bp?
69