Greatest Hits

16
votes
5answers
44k 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 ...
8
votes
5answers
97k 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, ...
3
votes
3answers
10k views

How to update solaris 10 to be safe from shellshock bug?

Saw this post here. Logged into my Solaris server in ssh and tried patchadd 19689293 and it just says it cannot find the patch.
9
votes
4answers
33k views

Nginx 1 FastCGI sent in stderr: “Primary script unknown”

My first time using Nginx, but I am more than familiar with Apache and Linux. I am using an existing project and when ever I am trying to see the index.php I get a 404 File not found. Here is the ...
5
votes
2answers
45k 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?
60
votes
10answers
41k views

How can I get the size of an Amazon S3 bucket?

I'd like to graph the size (in bytes, and # of items) of an Amazon S3 bucket and am looking for an efficient way to get the data. The s3cmd tools provide a way to get the total file size using s3cmd ...
11
votes
7answers
71k 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 ...
4
votes
1answer
28k views

Windows Server 2008 R2 - Remove Product Key to Force Reactivation after Deployment

I have a VM configured with internal software that needs to be sent to an outside party for evaluation. As it stands, the user who configured it also activated the software with a company issued MSDN ...
11
votes
6answers
28k 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 ...
44
votes
5answers
47k 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 ...
12
votes
4answers
50k views

How do you wait for an exe to complete in batch file?

I'm trying to create a script to execute an exe on shutdown in order to install sp1. my script goes something like (not actual bat script). If installed GOTO END Install.exe END: My problem is ...
4
votes
8answers
106k 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 ...
2
votes
7answers
77k 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, ...
34
votes
8answers
8k 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 ...
43
votes
4answers
57k 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 ...
1
vote
9answers
79k 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 ...
53
votes
5answers
57k views

Clean way to write complex multi-line string to a variable

I need to write some complex xml to a variable inside a bash script. The xml needs to be readable inside the bash script as this is where the xml fragment will live, it's not being read from another ...
52
8
votes
9answers
47k 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 ...
58
30
votes
2answers
28k views

_default_ VirtualHost overlap on port 443, the first has precedence

I have two ruby on rails 3 applications running on same server, (ubuntu 10.04), both with SSL. Here is my apache config file: <VirtualHost *:80> ServerName example1.com DocumentRoot ...
123
votes
6answers
13k 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 ...
54
votes
11answers
10k 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. ...
17
votes
3answers
65k 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 ...
48
votes
3answers
53k 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 ...
21
votes
4answers
80k views

How to filter http traffic in Wireshark?

I suspect my server has a huge load of http requests from its clients. I want to measure the volume of http traffic. How can I do it with Wireshark? Or probably there is an alternative solution using ...
5
votes
4answers
17k views

SSH issues: Read from socket failed: Connection reset by peer

I compiled OpenSSH_6.6p1 on one of our server. I am able login via SSH to the upgraded server. But I am not able to connect to other servers running OpenSSH_6.6p1 or OpenSSH_5.8 from this. While ...
14
votes
3answers
44k 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 ...
27
votes
12answers
42k views

Can't get SSH public key authentication to work [on hold]

My server is running CentOS 5.3. I'm on a Mac running Leopard. I don't know which is responsible for this: I can log on to my server just fine via password authentication. I've gone through all of ...
61
18
votes
10answers
8k views

Shellshock: How do I know if my server is compromised + suspicious files to look out for

Three questions which I hope someone can help answer: How do I know if my server is already compromised due to the Shellshock bug ? If it was compromised, is there a particular folder where I should ...
10
votes
10answers
54k 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 ...
0
votes
4answers
16k views

Fix/Bypass “Cannot connect to the real website-blocked” error in Google Chrome with OpenDNS blocking

I have a large problem with Chrome in my organisation. I use DNS to manage web site blocking, for sites which are not appropriate and are potentially a risk to the organisation where I do this. I ...
8
votes
4answers
50k 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 ...
63
votes
9answers
70k 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 ...
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 ...
1
vote
2answers
12k views

how to fix corrupt, not cleanly closed and upgrade needing tables in mysql

When I restart mysql server in Debian, I always have the below messages. How to make the messages disappear or fix the problem/corrupted tables? debian:~# /etc/init.d/mysql restart Stopping MySQL ...
9
votes
2answers
28k 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 ...
8
votes
7answers
60k 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 ...
48
votes
1answer
53k 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 ...
9
votes
4answers
38k 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 ...
23
votes
8answers
50k views

how to find out mac addresses of all machines on network

Is there some easy way to find out mac address of all machines on my network rather than doing an SSH into each and ifconfig | grep HWaddr if there are 300 machines on network I really need some easy ...
4
votes
6answers
30k views

SQL - an error occurred during the pre-login handshake

Until yesterday evening, I was able to connect to my server from my local machine. Now, I get the following error: A connection was successfully established with the server, but then an error ...
18
votes
8answers
11k 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 ...
4
votes
2answers
26k views

List All Groups and Their Members with PowerShell on Win2008r2

I am new to powershell, but I've been reading manuals and practiced a little bit. My objective is to List all users in all Security Groups under specified path. I have found the way to do it: ...
22
votes
9answers
44k views

Windows server last reboot time

How can I find a Windows server's last reboot time, apart from 'net statistics server/workstation'?
52
11
votes
5answers
34k views

Dump a linux process's memory to file

Is it possible to dump the current memory allocated for a process (by PID) to a file? Or read it somehow?
20
votes
3answers
34k views

How do I upgrade to the latest PHP version in CentOS with yum?

I found some blog posts about this, but it's rather lack of descriptions on possible side effects. I could really use some detailed on these steps: How to add a repo that provides PHP 5.4 into yum ...
22
votes
7answers
65k views

Are there any free NFS clients for Windows 7?

I have Windows 7 Professional, but the NFS Client for Windows is only included in the Enterprise and Ultimate editions. I would like to connect some Windows machines to our NFS server so I can drop ...
31
votes
8answers
52k views

OpenVPN vs. IPSec - Pros and Cons, what to use?

Interestingly I have not found any good search results when searching for "OpenVPN vs IPSec". So here my question: I need to setup a private LAN over an untrusted network. And as far as I know, both ...
6
votes
4answers
33k views

w1228 romb batt < 24h

I just got this message on the front panel of one of our servers, a Dell PowerEdge 2900. I believe this means that the RAID controller card battery is nearly dead. The question that I have is what ...
23
votes
9answers
53k views

How do I find out whether a port is available on Ubuntu 8.04?

Is there any command I can run from bash that will tell me whether a port is already open?
40
votes
1answer
52k views

sudoers: how to disable requiretty per user

I don't want to uncomment the line in /etc/sudoers: Defaults requiretty Instead, I only want a certain user not to require a tty. How can this be done?
47