Troubleshooting is a form of problem solving, often applied to repair failed products or processes.

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41
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8answers
25k views

Environment variables of a running process on Unix?

This is to troubleshoot some problems related to environment variables .. On Windows, I could do this by using tool such as ProcessExplorer to select particular process and view values of each ...
17
votes
9answers
4k views

Your troubleshooting rules, approach to troubleshooting?

Do you have any general rules that you fall back on when you troubleshoot a difficult network/hardware/software problem? Eg: "I isolate the source of the problem by testing a peripheral with a second ...
16
votes
10answers
1k views

Etiquette of Troubleshooting Problems In The Workspaces Of Others

A visibly upset colleague approached our technical support team this morning. She noted a member of our team had changed her workspace: Her monitor was turned off (she expected standby mode). Her ...
13
votes
3answers
16k views

page allocation failure - am I running out of memory?

Lately I've noticing entries like this one in the kern.log of one of my servers: Feb 16 00:24:05 aramis kernel: swapper: page allocation failure. order:0, mode:0x20 This is what I'd like to know: ...
12
votes
4answers
306 views

How do you troubleshoot wireless woes?

Sometimes I have to troubleshoot machines on my LAN which have flaky wireless connections without any seemingly logical reason. Contrary to "normal" network connections in most cases I don't know ...
11
votes
1answer
297 views

Harddisks falling offline for unknown reason

I have 7 systems running the setup below. Now and then a different disk falls offline, but on closer inspection the disk is good and not faulty and works flawlessly for at least another year. Since ...
10
votes
12answers
540 views

What's the first thing you check when an untouched unix server starts going berserk?

So you have this neatly setup unix server and it's super fast and works swell and everything is great for months, and suddenly all kinds of weird errors start showing up for a variety of different ...
10
votes
6answers
15k views

Why was my ping answered by a different IP address than the one pinged?

While trying to setup a MSSQL clustering solution, I am running into a problem that is outside of my expertise that is related to networking. I was trying to find a free IP to used for my node. I ...
9
votes
7answers
8k views

Troubleshooting a “slow” network

We've all had a complaint that the "network" is "slow" at some point: might be localized to one room (switch) or one computer, might just be Internet (DNS? Browser issue?), might be just one ...
9
votes
4answers
2k views

How to use kdump/crash to investigate an OOM issue?

The problem A server crashed after multiple "Out of memory" messages and I am trying to pinpoint the culprit. If it is in userland - which process. If it is in the kernel - which kernel module. ...
8
votes
3answers
15k views

What is the ibdata1 file in my /var/lib/mysql directory?

Logging in to my Webmin control panel, I noticed that virtually all of my disk space is full. I searched for the ten largest files/ directories on my system and found that a file called ibdata1 is ...
8
votes
4answers
5k views

Slow network speeds - what should I check?

Users are reporting that it's taking a long time to access files on the network, browse intranet sites, etc. What should I check?
8
votes
3answers
815 views

Performing root-cause analysis

I want to learn more about how to perform root-cause analysis. More times than not, our department tells the user to try rebooting (thier Windows XP system), which actually "fixes" a good number of ...
7
votes
3answers
506 views

How to troubleshoot Windows? Post your checklist [closed]

There is sometimes a situation when Windows suddenly goes crazy: is slow, unresponsive, some things don't work, it crashes. I wonder how do you approach diagnosing those issues. I'm merely a ...
7
votes
2answers
2k views

Troubleshooting strategy for very poor iSCSI/NFS performance

We have a new Synology RS3412RPxs that offers iSCSI targets to three Windows 2008 R2 boxes and NFS to one OpenBSD 5.0 box. Logging into the RS3412 with ssh and reading/writing both small files and ...
5
votes
6answers
806 views

How to do periodic Sql Server performance monitoring and troubleshooting?

What are the best tools and processes for periodically monitoring and troubleshooting sql server performance issues?
5
votes
8answers
4k views

creating decision tree based troubleshooting documentation?

We troubleshoot a lot of server and network issues and follow a loose set of steps on what to do in different cases. With more and more people and responsibility, the need for standardization is ...
5
votes
5answers
4k views

“Microsoft” has an online tool for troubleshooting Exchange issues - is it nifty?

*please note, I've changed the question in response to the suspicion that this site is dubious. I found this today - https://www.testexchangeconnectivity.com/ Pretty nifty! (or maybe not?) ...
5
votes
3answers
3k views

Troubleshooting linux server reboots?

I have a Linux server I've just set up, debian squeeze, 2.6.32-5-amd64, and over the past week it's rebooted three times, twice in one day. There was no power outage that I am aware of (and it's ...
5
votes
2answers
789 views

Delegate permissions to subfolder in TFS project

I need to give a TFS Project Group contributor privileges to a Source Control subdirectory in a TFS project. I can connect successfully as someone from this group but can't browse Source Control, ...
4
votes
7answers
490 views

General tips for interpreting error logs

Reading log files can be pretty frustrating as, by nature, their content says as much about the developer who penned them as the problem itself. Do you have any general purpose tips for interpreting ...
4
votes
4answers
218 views

Troubleshooting wireless network in a 4000 square feet office

I work for a non-profit organization in a 4000 sf office with 30 staff. All laptops are connected to the network wirelessly. We have one switch (TP-Link TL-SF1008D Ethernet Switch) and three routers ...
4
votes
5answers
3k views

How to translate error number to 'errno' constant?

Suppose I have an application running on a UNIX box that is failing with a system error status of '13'. Now, I can easily look up this value in errno.h, to find out that it is a permission-denied ...
4
votes
2answers
2k views

Cannot mount /dev/sdc1 on Debian 5.0, special device /dev/sdc1 doesn't exist

I'm trying to fix an odd problem I'm having that I've never seen or heard of before. I have a disk, /dev/sdc and I'm trying to mount it, but cannot. sudo mount /dev/sdc1 /mnt mount: you must ...
4
votes
8answers
22k views

Unable to logoff, disconnect, or reset terminal server user in production environment

I'm looking for some ideas on how to disconnect, logoff, or reset a user's session in a 2008 Terminal Server (unable to login as the user either as it is completely locked-up). This is a production ...
4
votes
2answers
277 views

List of Sysadmin Troubleshooting “Fire Drills”

One of the hardest things to do is to train sysadmins to solve problems (think) in a consistent way, especially when under pressure, the emergency bells are ringing, etc. For some training sessions, ...
4
votes
2answers
6k views

Troubleshooting Windows EAP/RADIUS connectivity issues

So, I guess the short version of the question is: I'm unable to get clients to connect to an enterprise-WPA wireless network after setting up a "new" NPS server and a new CA. After I manually ...
4
votes
2answers
1k views

Putty + Bash + Screen, up arrow for history not working (Ubuntu 11.10)

I have a fresh install of Ubuntu Server 11.10 that I am logging into SSH via PuTTy. When I am inside screen, I cannot use the up arrow to recall bash history (though this works outside of screen). I ...
3
votes
5answers
2k views

How can I troubleshoot a broken on/off switch?

I have a file server that was recently relocated in a transoceanic move. It isn't under warranty, as it was a custom-built in-house tower. When I hooked everything up and tried to boot it, the system ...
3
votes
12answers
6k views

Citrix degrades with 100% CPU

We have a Citrix PS4.0 farm made up of 2 physical and 2 virtual Citrix servers. Any one of them at some point or another will eventually degrade in performance due to hitting 100% CPU usage. I can ...
3
votes
3answers
168 views

What could cause two devices to refuse to link?

This is a curious case where all the devices at hand will link with one another, except for two that just won't detect one another. One device is a single board computer (SBC) with a gigabit nic, the ...
3
votes
7answers
610 views

Wireless network signal strength troubleshooting… where to start?

Here is the information displayed by the wireless router (see end of post). The problem is that my netbook does not get any signals from the router if moved more than 3 feet (yup, three feet) away ...
3
votes
3answers
169 views

huge slowdown in network of 40 nodes when local DNS is up

We have a LAN with ~40 workstations (mostly Windows) and a couple of servers. All of them use an internal DNS (196.168.0.4 running BIND 9.5.0-P2) and a gateway (192.168.0.1 running OpenBSD Packet ...
3
votes
3answers
2k views

How to troubleshoot events in the Windows Event Logs?

How do you troubleshoot events that are not clear when you read them? Is there a website to search for those Event IDs and errors? In the following example event it is clear that the gateway ...
3
votes
1answer
60 views

Virtual Server HDD shrinks without apparent reason

We have a virtual hosted Linux server, and in the last few months every now and then the HDD shrinks from 400GB down to the exact byte count that is in use. All existing data can be downloaded and ...
3
votes
1answer
1k views

Troubleshooting Windows Server 2012 storage spaces

I'm trying the new "Storage Pools" feature on Windows Server 2012, and I've created several disks on the pool. When I restart the server, some of the disks (two, out of four) do not attach ...
3
votes
4answers
3k views

How to diagnose a hang when creating a new folder in explorer.exe

I have been having some issues with explorer.exe hanging when I create a new folder. If I use Analyse Wait Chain in the Resource Monitor it says "One or more threads of explorer.exe are waiting to ...
3
votes
1answer
493 views

Word 2003 Normal.dot template always becoming corrupt

I have a user who always seems to have an issue with his normal.dot file becoming corrupt. In the past I've deleted or renamed the normal.dot file, and reopened to create a new one. This seem to fix ...
3
votes
2answers
1k views

Alternate Out of Order TCP Packets problem

I have a Windows network with embedded nodes connected to a series of Cisco switches. I have been seeing some serious network problems starting a few days ago. I used Wireshark to capture the network ...
3
votes
1answer
793 views

Odd one-way ping issue that I can't wrap my head around

Long time lurker, but today I encountered an odd problem that will bug me until resolution :-) It seems to be presenting as a one-way ping issue from one server to a failover cluster. All machines ...
3
votes
0answers
172 views

Monit will not start my node js app

I have a problem with Monit that I use for monitoring of my Node.js app. I just moved from a single core machine to a multi core one. On both of them I run Ubuntu 11.10. On the old one this was ...
3
votes
5answers
2k views

Open ports broken from internal network [duplicate]

Quick summary: Forwarded port works from the outside world, but from the internal network using the external IP the connection is refused. This is a simplified situation to make the explanation ...
2
votes
8answers
8k views

How can I install Windows 7 without burning a DVD or using a USB Drive?

I downloaded the .iso of Windows 7 and would now like to install it as my main OS. However I can't because I don't have a DVD Burner, a 2+ GB USB Drive, or a external HDD (or extra HDD). So how can I ...
2
votes
3answers
724 views

IBM Xseries 3400 only working while power button holding pressed

I have an IBM xSeries x3400 Intel Xeon server which only works while someone holds in the power button. My server stopped working and I sent it to IBM Service. After a few hours they told me I could ...
2
votes
6answers
841 views

My Ubuntu 10.04 server kills all WAN bandwidth when it's attached to my LAN. Where do you begin troubleshooting?

First I should say that my Linux knowledge is minimal; just enough to set up some servers (Apache, Tomcat, Couch, etc). I built a MiniITX server to host some simple sites, act as an SSH tunnel while ...
2
votes
9answers
22k views

Can ping machine by IP but not by name [closed]

On my home network, connected by means of a LinkSYS WCG200 Wireless-G Cable Gateway and a Unicom switch I have several computers. One of these is an XP Home machine that I can ping by IP but not by ...
2
votes
3answers
1k views

Email delivery is slow between us and counterparty. What can I do to determine root cause?

Emails between us and a specific counterparty are delayed. To give you some idea, we send 10 messages and over 40% arrive with a 20 (or greater) minute delay. We even had two messages arrive in 50 ...
2
votes
2answers
205 views

Troubleshooting Group Policies?

we built a plain Windows 2008 Server park a few months back, and set up a few Group Policies. Most of them seem to work fine, but once in a while I have the feeling that one or more have not been ...
2
votes
5answers
1k views

How can I troubleshoot an immediate computer shutdown?

I've had my desktop for ~4 years now, and recently it started behaving really badly: Whenever I run a Flash webgame or anything that takes up a great deal of memory - like a game, for example - ...
2
votes
5answers
1k views

How to troubleshoot hanging linux server

I have several Ubuntu Server 8.04 machines at a remote location. Every couple of months or so, one of them would stop responding and need to be power cycled. From looking at my log files it seems that ...