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

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11
votes
1answer
740 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 ...
1
vote
1answer
228 views

Cisco ASA: Terrible network speed once or twice a day, fine otherwise

I've been trying to get to the bottom of this for a while now and, well, it seems like I can't. We have two servers behind an ASA5505 (software version 8.3) at a datacenter. They run a wide variety of ...
1
vote
1answer
2k views

How can i find out why my web server is refusing traffic from my web proxy?

I have a bit of an odd problem that I can't seem to figure out. I will preface this question with the fact that this exact setup was working just fine, and for some reason has stopped working ...
0
votes
0answers
189 views

FreeBSD 7 syslog messages: “kernel: 15.xxxxxxxxxxxxxxx too long” (or “too short”)?

I'm experiencing poor performance on an old FreeBSD system and the only anomaly I see so far are syslog messages of the form: Jul 1 12:10:50 myserverXXX kernel: 16.0ccdd219377c0d80 too long Jul 1 ...
2
votes
1answer
2k views

iptables FORWARD port to internal server

I've been struggling with a FORWARD policy that isn't working the way I'd like, and I can't figure out what is causing the session to fail. I hope someone can help. My goal is to forward port 3000 ...
-4
votes
3answers
93 views

How to debug and prevent flaky unreliable IT environment? [closed]

I am not an IT admin, I'm a software developer (microsoft stack) and I'm trying to understand what is wrong with the IT environment of one of our customers. We have deployed our client\server ...
-3
votes
2answers
2k views

Alternatives to wireshark? [closed]

What would be a good option to troubleshoot an interaction of browser with a server besides wireshark? I mean being able to see what the browser sends and receives. Is firebug a good alternative or is ...
4
votes
4answers
317 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 ...
2
votes
1answer
99 views

Is my server toast?

Last night I received an e-mail from mdadm about the possible failure of two drives on my array. The raid array was set up as a 4 2TB drive raid5 with one hot spare. Is this system truly fried? Did ...
-1
votes
1answer
565 views

DHCP Troubleshooting [closed]

I am working at a branch office and have been tasked with changing out the DHCP scope to match the overall corporate IP address scheme. The main office assigned me an IP address range of ...
3
votes
3answers
188 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 ...
1
vote
3answers
8k views

How do I identify unknown protocols on my Cisco 2811?

I have a misbehaving Cisco 2811. It serves our office of 20 with internet and phones via Call Manager Express. Except that lately the phones aren't working right and internet is choppy. The outside ...
16
votes
3answers
31k 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 ...
0
votes
0answers
154 views

Windows Server 2008 R2: Weekly network failure

Thought I would throw the question on here, as I'm not a seasoned sysadmin... Every Thursday (or there about) at no particular time, the server becomes unresponsive to its usual network operations ...
0
votes
1answer
12k views

Windows “net use” command throwing error, “System error 1909 has occurred” [duplicate]

What is the likely cause of this, if the command is run on Windows Server 2008? It appears that this account is an administrator on this box. I'm running the Windows command line as an administrator ...
2
votes
2answers
227 views

How do I find where packets are coming from that are being blocked by an ACL?

I have an ACL to prevent regular workstations from accessing the management vlan on our switch. Every 5 minutes we get the following log entry: %SEC-6-IPACCESSLOGS: list mgtvlan-acl denied 0.0.0.0 ...
10
votes
4answers
3k 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. ...
2
votes
4answers
2k 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 ...
-1
votes
1answer
420 views

Windows Server 2008 Troubleshooting: Server falling over on a timely basis [closed]

All, This is a generic question, and I know it will upset some people, for which I apologise. I have recently taken a new role, and part of that role involves some sysadmin for Windows 2008 Servers ...
2
votes
2answers
4k views

How to change SMP affinity of an IRQ on Ubuntu PV domU inside Xen XCP?

I'd like to change IRQ SMP affinity for reasons, outlined in this question: CPU0 is swamped with eth1 interrupts But I can't — I see Input/output error when I try to write to ...
0
votes
2answers
131 views

unexpected server power off

Once or twice per day I find a server I have powered off with no apparent reason. Info and what I've done until now: Nothing is being reported under /var/log/. Just normal server activity and then ...
2
votes
1answer
365 views

Measure Upload Speed between a client and our server

We host a SAAS application specially customized for multiple clients. For one customer in particular -- they are reporting sporadic performance issues from various locations on their network, in ...
0
votes
1answer
320 views

Troubleshoot IIS 6 and Intermittent SQL Server Connectivity Loss

I am not a System Administrator, but I am temporarily trying to fill that role. I have 2 Windows 2003 Servers. 1 server has my Microsoft SQL Database (SQL Server 2005) and the other is the web ...
1
vote
0answers
245 views

Apache taking up a lot of CPU while running request-tracker4

I am trying out a request-tracker installation on an EC2 micro instance. The specs for the micro instance are as follows 1) Ubuntu 12.04 64bit, 613MB RAM, 8GB Hard Drive 2) Running request-tracker ...
0
votes
1answer
333 views

Diagnosing SAN connectivity issues (RHEL5)

We are currently utilizing GFS2 to share a SAN LUN between 3 servers. However due to a feature problem with vendor software we are using, we currently have the volume unmounted on two of the boxes, ...
0
votes
4answers
1k views

Server freeze - how to debug

I am running a Debian virtual server with Apache, PHP, MySQL. There is just 1 website with very low traffic running but the server very often (almost everyday) freezes and does not respond. When ...
3
votes
1answer
2k 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 ...
0
votes
1answer
217 views

How can I easily test connectivity to external sources with WinHTTP?

I've got an server application that uses Winhttp to fetch information from an external source. Occasionally, I'll need to troubleshoot connectivity issues and I'd like an easy way to test connections ...
0
votes
1answer
261 views

Windows Server 2008 R2 Troubleshooting PID Leaking

One of our servers has been leaking PID like crazy. I wrote a simple scheduled script, and it seems that every day the highest PID increases by approx. 300'000. E.g., if on Aug.24 00:00 the highest ...
1
vote
1answer
316 views

What are some steps to trouble shoot denied HTTPS requests in IIS 7?

I'm hosting a site in IIS 7 that's using a wildcard certificate from RapidSSL. To date there's been no issues of people not being able to connect to the site with SSL. Now we have a client who can't ...
1
vote
1answer
127 views

ASP.NET error logging locations and troubleshooting

Say an ASP.NET website suddenly starts returning a 500 error code with a blank page (not serving the configured error document). Where might I find error reports and/or clues as to what is happening, ...
3
votes
1answer
1k 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 ...
5
votes
3answers
13k 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 ...
0
votes
2answers
179 views

Server unresponsive, messages shown on console but not in log files

I'm using Ubuntu Server 10.04.4, and once in a while the server hangs (once a month) and is totally unresponsive. The tty is flooded with messages like these. The problem is that these messages are ...
1
vote
1answer
2k views

“Device not ready” on a network share in Windows 7

I have two computers C1 and C2 runing Windows 7 and both of them are members in a domain. On C1 I have an USB hard-disk which I shared for the users U1 and U2 giving them Read-Only permissions on the ...
0
votes
1answer
54 views

How to troubleshoot banned connections on OS X / Ubuntu

I have an ubuntu 11.10 VM running on an OSX machine. Every once in a while some services become inaccessible from specific IPs (e.g. sometimes just ssh is blocked, and sometimes both ssh and https.) ...
3
votes
3answers
24k views

How to investigate unexpected Linux server shut down?

In a new Xeon 55XX server with 4xSSD at raid 10 with Debian 6, I have experienced 2 random shut downs within two weeks after the server being built. Looking at bandwidth logs before shut down does not ...
3
votes
0answers
195 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 ...
1
vote
0answers
825 views

alfresco, tomcat crashes on startup, no clues in the logs

I have installed an alfresco community edition 4.0 on a Win 2003 R2 with 3GB of RAM. I've used alfresco for some hours, i've created a user, uploaded some documents. But now, restarting it, tomcat ...
8
votes
2answers
3k 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 ...
3
votes
3answers
186 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 ...
1
vote
2answers
2k views

Troubleshooting ESXi hardware freeze with PCI Passthrough

I have a Supermicro X9SCM board with a Atheros AR5008 PCI Express card (D-LINK DWA-556, Device=0024&Vendor=168C). The card can successfully be marked for PCI passthrough in ESXi (I tried versions ...
-3
votes
2answers
148 views

Server keeps crashing [closed]

I just recently rented a new server which is being used for hosting files and converting them. however for some reason the server keeps crashing every few hours, how can I find out the reason why my ...
0
votes
3answers
246 views

How to verify DNS change is active

I have DNS service from a third party, which provides an webapp for changing the DNS. I changed the DNS settings to point one of the domains I control to our new IP, but it's been hours and there was ...
-1
votes
1answer
50 views

PC Shutting Down Without Warning [closed]

I have a Windows 7 PC that is shutting down without warning, seemingly at random. Here are the symptoms and notes: PC seemingly turns off completely. After taking off the cover it turns out the ...
2
votes
1answer
1k views

Fortinet: Is there any equivalent of the ASA's packet-tracer command?

I would like to know if there is not Fortigates an equivalent of the packet-tracer command that we can find on the ASA. Here is an example of execution for those who don't know it: NAT and pass : ...
1
vote
1answer
1k views

WHEN does IIS 6.0 Application Pool CRASH with memory issues?

We've been having Out of Memory issues with our mixed classic ASP/.NET site for quite some time. Basically, we see a couple of different cases: Some request (SQL query that returns a LARGE ...
0
votes
1answer
284 views

Cisco 878 Router Physical Layer troubleshooting

My problem: Upon connecting the FastEthernet0 with a straight-through cable to a Catalyst switch, the line protocol comes up briefly and then goes down. Interface goes down too, I now have this on my ...
1
vote
0answers
245 views

How to troubleshoot intermittent winsock 10054 errors on Windows Server 2003 SP2

We are getting 10054 errors in a couple of our applications on one server running Windows Server 2003 SP2. This happens intermittently, and we also have other similar servers running the same ...
0
votes
1answer
4k views

What factors can disrupt a VSAT connection?

In some locations, the only option for an internet connection is to use some form of Satellite dish. Like any wireless medium these can be quite tricky to troubleshoot. What factors have you ...