Greatest Hits

16
votes
2answers
18k views

ia32-libs : Depends: ia32-libs-i386 but it is not installable

I am trying to install ia32-libs (a dependency to build the VirtualBox sources) on my Debian x86_64 box, however it's giving me the error: The following packages have unmet dependencies: ia32-libs : ...
36
votes
4answers
95k views

How can I port forward with iptables?

I want connections coming in on ppp0 on port 8001 to route to 192.168.1.200 on eth0 on port 8080 I've got these two rules -A PREROUTING -p tcp -m tcp --dport 8001 -j DNAT --to-destination ...
20
votes
4answers
74k views

How do I install an rpm that complains about rpmlib(FileDigests) <= 4.6.0-1?

Im trying to install an rpm file on CentOS 5 and Im not sure how to resolve this issues it brings up: $ rpm --install epel-release-6-5.noarch.rpm warning: epel-release-6-5.noarch.rpm: Header V3 ...
73
votes
12answers
40k views

How do diff over ssh?

How do I diff files/folders across machines provided that the only connectivity available is ssh?
102
13
votes
3answers
60k views

How to write ISO image to usb memory stick from linux command-line?

I'm having trouble figuring out how I would write an ISO disk image to a USB flash memory device from the command line in Ubuntu. I have the Startup Disk Creator utility, but I need to be able to ...
18
votes
7answers
79k views

Disable password complexity rule in Active Directory

Where do I go to disable the password complexity policy for the domain? I've logged onto the domain controller (Windows Server 2008) and found the option in local policies which is of course locked ...
53
votes
13answers
54k views

How to reconnect to a disconnected ssh session

Is there a way to connect to an ssh session that was disconnected? We are having problems with our network connection to a remote site that we are working on separately; however, in the mean time we ...
46
votes
3answers
59k views

Is there a way to view the members of an Active Directory group if you aren't a domain admin and can't log into to a domain controller?

Is there a way to view the members of an Active Directory group if you aren't a domain admin and can't log into to a domain controller?
16
votes
3answers
83k views

How to properly set permissions for NFS folder? Permission denied on mounting end.

I'm trying to connect to an NFS folder on my dev server. The owner of the folder on the dev server is darren and group darren. When I export and mount it to my Mac using the Disk Utility it mounts, ...
69
votes
8answers
97k views

How do I create a symbolic link in Windows?

Windows Vista added the ability to create symbolic links to files and directories. How do I create a symbolic link and what are the current consumer and server versions of Windows that support it?
18
votes
2answers
40k views

DNS - NSLOOKUP what is the meaning of the non-authorative answer?

When I do a NS Lookup, for some domains I get the reply saying Non-authorative answer:. I want to know what it means? Got answer: HEADER: opcode = QUERY, id = 3, rcode = NXDOMAIN ...
101
votes
12answers
99k views

How to set up Nginx as a caching reverse proxy?

I heard recently that Nginx has added caching to its reverse proxy feature. I looked around but couldn't find much info about it. I want to set up Nginx as a caching reverse proxy in front of ...
59
votes
8answers
67k views

how to set global PATH on OS X?

I'd like to append to the global PATH variable on OS X so that all user shells and GUI applications get the same PATH environment. I know I can append to the path in shell startup scripts, but those ...
23
votes
13answers
42k views

Why is the response on localhost so slow?

I am working on a tiny little PHP project for a friend of mine, and I have a WAMP environment setup for local development. I remember the days when the response from my local Apache 2.2 was immediate. ...
45
votes
2answers
27k views

How do VLANs work?

What are VLANs? What problems do they solve? I'm helping a friend learn basic networking, as he's just become the sole sysadmin at a small company. I've been pointing him at various questions/answers ...
62
votes
13answers
54k views

In my /etc/hosts/ file on Linux/OSX how do I do a wildcard subdomain?

I need to test sub-domains on my localhost. How can I effectively have this result of adding *.localhost.com to m /etc/hosts/ file? If it's not possible, how do I work around this problem? I need ...
19
votes
3answers
32k 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 ...
57
votes
7answers
94k 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 ...
27
votes
14answers
54k views

What is a patch panel?

What is a patch panel? How it is different from (layer 2) switch? EDIT: I think my primary question (and confusion) is this: Why don't network connections go straight to the switch? Don't we still ...
45
votes
3answers
47k views

How to add dependency on a Windows Service AFTER the service is installed

I have a Windows Service that makes use of a SQL Server database. I don't have control over the installation of the service, but would like to add a dependency on the service to ensure that it starts ...
18
votes
11answers
22k views

What are your best senior level Linux interview questions

Every now and then on this site there are people asking what are some sys admin interview questions. Mostly when reading them they are all junior to mid-level questions. I'm wondering what are your ...
99
15
votes
2answers
75k views

I cannot connect to my local SQL Server 2008?

I've just installed SQL Server 2008 and I cannot connect to it with SQL Server Management Studio. My intention is to just let my local windows user be authenticated but I am not totally sure how to do ...
59
votes
7answers
51k views

How can I run Debian stable but install some packages from testing?

Say you're running a server and you don't want to upgrade to Testing (Squeeze) from Stable (Lenny) to just install a required package or two. What's the best way of installing only certain packages ...
46
votes
6answers
81k views

How do I create user accounts from the Terminal in Mac OS X 10.5?

I would like to be able to create new users in Mac OS X 10.5 remotely after ssh'ing into the machine. How do I do this?
25
votes
4answers
61k views

Adding a directory to $PATH in CentOS?

We just got our new server(s) up and we're running CentOS on them all. After successfully installing Ruby Enterprise Edition, I would now like to add the REE /bin (located at ...
33
votes
6answers
104k views

How can I tell what version of IIS is installed?

I've got a box running Win2k3 and some directions from Microsoft KB about SSL certificates, for IIS 5.0 and 6.0. How can I tell which version of IIS is currently installed?
47
votes
11answers
92k views

How do I find if there is a rogue DHCP server on my Network?

What's the best approach towards determining if I have a rogue DHCP server inside my network? I'm wondering how most admins approach these kinds of problems. I found "DHCP Probe" ...
43
votes
9answers
50k views

How can I export the privileges from MySQL and then import to a new server?

I know how to export/import the databases using mysqldump & that's fine but how do I get the privileges into the new server. For extra points, there are a couple of existing databases on the new ...
296
votes
12answers
51k views

How do I deal with a compromised server?

This is a Canonical Question about Server Security - Responding to Breach Events (Hacking) See Also: Tips for Securing a LAMP Server Reinstall after a Root Compromise? Canonical ...
13
votes
3answers
52k views

How to stream live video from a linux server?

Here is what I want to do. Looked around but didnt find any straight answer. I have a Linux box running websites using Ubuntu/MySQL/Apache. I have my own static IP as well, i.e. not using web hosting. ...
21
votes
13answers
35k views

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 ...
7
votes
3answers
35k views

What is a domain controller, when is it needed, and how to set it up?

I would like to know what do we mean by Domain controller and how do we make a system a Domain Controller and when do we have to make a system a DC?
24
votes
2answers
57k 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 ...
12
votes
9answers
72k views

Unable to connect to mysql through JDBC connector through Tomcat or externally

I've installed a stock mysql 5.5 installation, and while I can connect to the mysql service via the mysql command, and the service seems to be running, I cannot connect to it through spring+tomcat or ...
17
votes
9answers
13k views

`mysql_upgrade` is failing with no real reason given

I'm upgrading from MySQL 5.1 to 5.5, running mysql_upgrade and getting this output: # mysql_upgrade Looking for 'mysql' as: mysql Looking for 'mysqlcheck' as: mysqlcheck FATAL ERROR: Upgrade failed ...
10
votes
8answers
82k views

How to create a service running a .bat file on Windows 2008 Server?

I've created the service using sc create myService binpath=myservice.bat But when I start it, it fails with the following error message: [SC] StartService FAILED 1053: The service did not ...
22
votes
10answers
64k views

How to take ownership of files from the command line?

Every so often I run into a file that I need to take ownership of. I normally use cacls for changing ntfs permissions, but it doesn't seem to do ownership. Under *nix I would run something like ...
36
votes
4answers
38k views

Can I automatically add a new host to known_hosts?

Here's my situation; I'm setting up a test harness that will, from a central client, launch a number of virtual machine instances and then execute commands on them via SSH. The virtual machines will ...
78
votes
2answers
24k views

How do I select which Apache MPM to use?

I'm a little confused between the different MPMs offered by Apache - 'worker', 'event', 'prefork', etc. What are the major differences between them, and how can I decide which one will be best for a ...
22
votes
4answers
69k views

Where to set java heap options (e.g. -Xmx) for Tomcat 6 under Ubuntu 9.04?

I'm running Tomcat using the tomcat6 package from Ubuntu 9.04, which makes a daemon out of Tomcat using jsvc. I'd like to know the proper way to set Java heap options like -Xmx for Tomcat. I'd like to ...
7
votes
3answers
39k views

How to delete domain user profile from a computer?

I'm wondering how to safely remove a domain user profile from a computer that is a part of a domain. I don't want to delete the account from the domain itself, I just need to remove the profile from ...
28
votes
14answers
60k views

Why does “Loading your personal settings” take forever?

I have come across dozens of user installations of Windows (XP) where, after logging in, the system stays stuck on this screen for a very long time. What are the possible causes? How can I diagnose ...
73
21
votes
9answers
103k 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 ...
21
votes
3answers
100k views

How to enable MySQL logging?

I am running MySQL 5.0.45 on OS X 10.6.1 and I cannot get MySQL to log anything. I am debugging an application and need to see all queries and errors. I added to the etc/my.cnf: [mysqld] ...
56
votes
9answers
80k 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 ...
58
39
votes
5answers
6k views

Monday morning mistake: sudo rm -rf --no-preserve-root /

Here's a an entertaining tragedy. This morning I was doing a bit of maintenance on my production server, when I mistakenly executed the following command: sudo rm -rf --no-preserve-root ...
6
votes
3answers
75k views

How to restore/import an Oracle database from dmp file?

I've recently recieved the dump file of the soon to be migrated Oracle Database. I've installed Oracle 10g and now i need to restore the original database. Can anyone give me a step to step ...
26
votes
3answers
71k views

Mount Remote CIFS/SMB Share as a Folder not a Drive Letter

Is there any way to mount a remote CIFS/SMB/SAMBA share as a folder/directory and not as a drive letter. For example, I want this map: \\Server\ShareName -> C:\Folder\ShareName Instead of the usual ...
13
votes
6answers
29k views

How to delete cached temporeraly credentials for a network share on a Windows machine without rebooting or logging off

This is more of a curiosity then a real problem, I am just to lazy to reboot or log off my laptop. I have connected to a network share on a Windows server with domain credentials from a non-domain ...
46
35
votes
6answers
50k views

how to check if a library is installed?

In linux, how do I check if a library is installed or not? (from the command line of course). In my specific case now, I want to check whether libjpeg is installed.