Greatest Hits

27
votes
9answers
79k views

Increase number of allowed remote desktop connections

Windows Server 2003 allows 2 non-console and one console remote desktop connections. Is there a way to increase the number of non-console sessions allowed?
23
votes
1answer
42k 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 ...
62
21
votes
10answers
64k views

Which is better: RAID5 + 1 Hotspare / RAID6?

Just curious, I have 6 x 1TB 7200RPM Near Line SAS for my new server. I can either configure it as RAID5+1 Hot Spare or RAID6. What should I choose?
15
votes
8answers
60k 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: ...
8
votes
2answers
42k 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 ...
51
votes
10answers
8k views

Why drop caches in Linux?

In our servers we have a habit of dropping caches at midnight. sync; echo 3 > /proc/sys/vm/drop_caches When I run the code it seems to free up lots of RAM, but do I really need to do that. ...
13
votes
5answers
60k views

Need to add a “Wait” command to a Powershell script

Here is my current code: Write-output “ENTER THE FOLLOWING DETAILS - When Creating Multiple New Accounts Go to EMC hit F5(refresh) and make sure previous new account is listed before ...
90
votes
9answers
29k views

Keeping a linux process running after I logout

I'm connecting to a Linux machine through SSH, and I'm trying to run a heavy bash script that makes filesystem operations. It's expected to keep running for hours, but I cannot leave the SSH session ...
22
votes
6answers
45k views

How do you increase a KVM guest's disk space?

I setup an Ubuntu guest on a CentOS KVM host with initially 6GB of disk space. How do I go about increasing the Ubuntu guest's disk space from the command line? EDIT #1: I'm using a disk image file ...
28
votes
7answers
48k views

How do I check the postfix queue size?

What's the postfix equivalent to sendmail -bp?
60
4
votes
8answers
103k views

How do I remove Windows Update uninstall files on Windows Server 2008?

I'm running Windows Server 2008 Standard running in VMware. It has 2 disks: system disk: 16 GB data disk: 500 MB I installed Visual Studio 2008 SP1 + MSDN and some small tools and ...
15
votes
3answers
62k 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 ...
22
votes
2answers
29k views

How to get the url of the current svn repo?

I have 2 svn checkouts that someone setup for me. Now I need to check these same files on another computer, but since I didn't check them out initially I don't know the urls to use when running the ...
26
votes
5answers
68k views

Why do we ping the IP 4.2.2.2 to test connectivity?

For as long as I can remember, I've always used the IP 4.2.2.2 when testing network connectivity using ping. What is significant about this IP, and when did this practice start?
37
votes
4answers
35k 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. ...
57
13
votes
4answers
34k views

How do I sleep for a millisecond in bash or ksh

sleep is a very popular command and we can start sleep from 1 second: # wait one second please sleep 1 but what the alternative if I need to wait only 0.1 second or between 0.1 to 1 second ? ...
83
votes
2answers
29k views

How can I see which flags Nginx was compiled with?

How can I check what modules have been added to an nginx installation?
10
votes
7answers
70k views

Problem adding Windows 7 64-bit print drivers to a 32-bit Windows 2003 print server

I have installed the final RTM version of Windows 7 Professional 64-bit on a test system before we begin the rollout in our company. I'm having problems connecting to several HP printers that we have ...
24
votes
4answers
6k views

Does a company have implied right to crawl my website?

I have found out that McAfee SiteAdvisor has reported my website as "may be having security issues". I care little about whatever McAfee thinks of my website (I can secure it myself and if not, ...
11
votes
6answers
27k views

CentOS 6 + LDAP + NFS. File ownership is stuck on “nobody”

I've been trying to get LDAP authentication and NFS exported home directories on CentOS 6 working for a few days now. I've gotten to the point that I can now login to the client machine using the ...
22
votes
7answers
52k views

How to display certain lines from a text file in Linux?

I guess everyone knows the useful Linux cmd line utilities head and tail. Head allows you to print the first X lines of a file, tail does the same but prints the end of the file. What is a good ...
23
votes
5answers
71k 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?
61
votes
1answer
38k 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?
53
7
votes
8answers
49k views

SSL Error - unable to read server certificate from file

I've been setting up SSL for my domain today, and have struck another issue - I was hoping someone could shed some light on.. I keep receiving the following error messages: [error] Init: Unable to ...
26
votes
3answers
57k views

How to install/change locale on Debian?

I've written a web application for which the user interface is in Dutch. I use the system's date and time routines to format date strings in the application. However, the date strings that the system ...
8
votes
9answers
55k views

psexec: “Access is Denied”?

Inspired by my previous question here, I've been experimenting with PSExec. The goal is to trip off some fairly simple scripts / programs on one WindowsXP machine from another, and as PowerShell 2 ...
40
votes
7answers
46k 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 ...
1
vote
9answers
78k views

Can ping Exchange server, can't connect Outlook to it

I can ping the Exchange server here at work, but Outlook doesn't connect to it. I've verified the server is indeed the Exchange server and I've tried using the IP instead of the server name. I am also ...
35
votes
7answers
36k views

Is it possible to alias a hostname in Linux?

Is it possible to alias a hostname in Linux? It has been asked by jmillikin at various Ubuntu forums as follows: Is it possible to create a hostname alias? Sort of like /etc/hosts, but with other ...
8
votes
5answers
91k views

Reverse DNS - how to correctly configure for SMTP delivery

I started a new service and we need to send emails to our customers (new account confirms, etc). My server is known as prod01.bidrodeo.com and resolves to 97.107.134.38 . For reverse DNS, ...
8
votes
3answers
40k views

How to check my PHP and MySQL version on Ubuntu VPS?

HI I am going to install MyBB but I am not sure whether I have installed the correct version of PHP and MySQL. PHP version 5.1.0 or above with XML Extension installed MySQL version 4.0 or ...
117
votes
6answers
12k views

Are SSD drives as reliable as mechanical drives (2013)?

SSD drives have been around for several years now. But the issue of reliability still comes up. I guess this is a follow up from this question posted 4 years ago, and last updated in 2011. It's now ...
40
votes
5answers
65k 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 ...
5
votes
2answers
60k views

Where can I download the latest 64-bit edition of Sonicwall SSL-VPN NetExtender for Windows 7?

Does anyone know where to download the latest edition of the 64-bit version of SonicWall SSL-VPN NetExtender for Windows 7?
4
votes
3answers
54k views

How do I mount a “GPT Protective Partition” in Windows XP?

I formatted an external USB harddrive while it was connected to a 32-bit Windows 2003 Server Std. edition server. After loading it up with files, I moved it to my Windows XP SP3 where it didn't show ...
12
votes
6answers
31k views

How do I access the list of currently logged on users through Terminal Services Manager in Windows Server 2012?

In Windows 2003 and 2008 we had Terminal Services Manager (see screenshot below). However in Windows server 2012 it's gone. Does anyone know how to access the list of currently remotely logged on ...
17
votes
3answers
60k views

“Possible SYN flooding” in log despite low number of SYN_RECV connections

Recently we had an apache server which was responding very slowly due to SYN flooding. The workaround for this was to enable tcp_syncookies (net.ipv4.tcp_syncookies=1 in /etc/sysctl.conf). I posted a ...
15
votes
5answers
40k views

where are the default ulimit values set? (linux, centos)

I have two CentOS (5) servers with nearly identical specs. When I login and do: ulimit -u on one machine, I get unlimited and on the other, 77824 When I run a cron like * * * * * ulimit ...
2
votes
7answers
74k views

Why am I getting 'File in use by Another User' and 'Application Sharing Violation' errors when trying to open & and save files?

We're getting this a lot lately. Windows 2008 Server Windows 7 & Vista Client PC's Microsoft Office 2007 When a user tries opening a file on our network drive (word doc, excel spreadsheet, ...
6
votes
8answers
44k views

How can I check whether port 5060 is open in centos?

How can I check whether port 5060 is open in centos? How can I test if my linux has real a real IP address and I set no iptables blocking rules or is there any tools which I can run in my linux so my ...
56
2
votes
1answer
16k views

How to disable user's password via puppet securely?

I have my SSH servers setup to use only Public Key authentication with password authentication disabled. When adding users through puppet I would like to disable user passwords. So far I have came ...
39
votes
6answers
54k 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. ...
16
votes
8answers
7k views

RAID-5: Two disks failed simultaneously?

We have a Dell PowerEdge T410 server running CentOS, with a RAID-5 array containing 5 Seagate Barracuda 3 TB SATA disks. Yesterday the system crashed (I don't know how exactly and I don't have any ...
5
votes
2answers
40k views

What is the difference between RDIMM vs UDIMM

I don't quite understand the differences between the two besides the obvious price differences. What does each offer over the other?
32
votes
5answers
31k 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 ...
13
votes
4answers
42k views

VirtualBox: How to set up networking so both host and guest can access internet and talk to each other

I was wondering if someone could give me a simple guide on how to set up virtual networking in VirtualBox (4.0.2) so that the following scenarios work: Both Host and Guest can access Internet Host ...
39
votes
4answers
53k 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 Leopard), which gives me an answer like this: % dig host.example.gov <*SNIP*> ;; ANSWER ...
42
45
votes
3answers
51k views

How to delete Instances in Amazon EC2 ? Change Pair Key?

How to remove Instances ? I test some Instances and now I terminate it. So, I want to remove it. I can't find delete or remove action. I just found terminate. How to change the pair key ? I don't ...
62
votes
9answers
68k views

Dealing with HTTP w00tw00t attacks

I have a server with apache and I recently installed mod_security2 because I get attacked a lot by this: My apache version is apache v2.2.3 and I use mod_security2.c This were the entries from the ...
15
votes
4answers
55k 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 ...