Last call to make your voice heard! Our 2022 Developer Survey closes in less than a week. Take survey.

Questions tagged [troubleshooting]

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

Filter by
Sorted by
Tagged with
0 votes
1 answer
24 views

Centos 7 OpenJDK Upgrade Confusion

Wanted to pick someone else’s brain on an issue I’m having and getting nowhere with. We have an older Linux server in our environment and I am looking to patch our openjdk to the Latest versions but ...
user avatar
0 votes
0 answers
21 views

MariaDB Replication Master Slave Login Slave Login Forbidden

Good day everybody, As a newbie, I apologize if I'm doing this wrong. About the situation: We have two physical Ubuntu servers. These are in the same network and act as master/slave servers. The ...
user avatar
  • 1
1 vote
0 answers
11 views

Block device suddenly full; can't identify a single file as culprit and SMART shows no drive errors [duplicate]

Setup Ubuntu 20.04 Dell PowerEdge R820 [PERC H710] 2x Virtual Drives (RAID-1 Boot, RAID-0 Work Drive) Everything been fine for 6 months No preceeding even, just suddenly, drive full. Details... This ...
user avatar
1 vote
0 answers
277 views

How can I see the memory content of nginx process?

Nginx 1.20.1 server working as a reverse proxy consuming a lot o memory and making the service stop requiring a system reboot. ModSecurity library is also configured on Nginx. You can see in the next ...
user avatar
  • 123
0 votes
0 answers
50 views

Log TCP Client port on apache mod_proxy

Using an Apache 2.4 Reverse Proxy (with mod_proxy) that connects to a backend HTTP service we have the following(simplified) series of TCP connections: client ClientIP:random_port1 ---> <IP1:443 ...
user avatar
  • 478
1 vote
1 answer
274 views

No incoming traffic on Hyper-V Adapter inside VM

I have a very annoying problem with my Hyper-V setup and it's bugging me quite a bit, because I can't figure out why. My Hyper-V Host is a Windows Server 2019 and has three network adapters. Adapter 1 ...
user avatar
  • 21
0 votes
1 answer
59 views

How to query linux kernel which storage-related operations are currently being run on the level of FS / block layer / SATA controller?

Every once in a while, our Linux LAMP server (using PHP-FPM, XFS on thin LVM on HW RAID, Centos8) becomes inaccessible and stops responding to HTTP(S) requests. Via centralized logging we found out ...
user avatar
5 votes
2 answers
1k views

Can tone ethernet cable into patch panel but it's not working

So we recently had to two major issues happen at a location. We had a lightning strike hit the building We updated switches after this lightning strike Now one thing that was 'hit' was a SOHO router....
user avatar
0 votes
0 answers
77 views

After upgrade from MongoDB 4.x to 5.0.2 shows Connection Refused trying to connect BD from Private Network

I have upgraded my MongoDB from 4.x to 5.0.2 into a Ubuntu 20.04 system. This server is an AWS EC2 Instance. After upgrade I can't connect my applications from other ec2 instances using the same ...
user avatar
  • 1
0 votes
1 answer
123 views

Something is closing connections in my CentOS VMs - how to best troubleshoot?

I have a setup with 3 VMs (1 application server on CentOS6 and 2 database servers on CentOS7). The last 1-2 weeks we have had issues with timeouts when connecting to the database servers (and between ...
user avatar
1 vote
1 answer
30 views

Has anyone cloned an HDD for a Macintosh IIvx?

Where I work as a sysadmin, we have an old Macintosh IIvx that is the only one left in the world with an obscure program on it that will cost the company a ton of money if they can't use it. Well, the ...
user avatar
0 votes
1 answer
168 views

router or reverse proxy - network failure

I have an edgerouter x sfp as the main router to the internet. To this router a server is connected with a reverse proxy docker running called swag eg. letsencrypt which I use to access nextcloud and ...
user avatar
1 vote
0 answers
74 views

WVD App attach launching windows file explorer

I'm trying to virtualize some apps and test the app attach feature with MSIX packages. I've followed all the steps, and expanded the MSIX into a VHD. I've uploaded the VHD and placed it in a hostpool /...
user avatar
0 votes
0 answers
61 views

Remote host can be connected to via SSH but cannot connect to the Internet

I am trying to find out why a remote host with which I can connect via SSH cannot connect to the internet. When I try to ping said server, it will answer back with 1 ping and every subsequent packets ...
user avatar
  • 103
1 vote
3 answers
1k views

Using ENV variables in Postfix and Dovecot configuration files

I'm trying to dockerize my mailing server and I'm having some troubles regarding how am I supposed to use environment variables inside Postfix and Dovecot configuration files (I'm using the latest ...
user avatar
  • 21
0 votes
1 answer
2k views

Kubernetes: kube-dns servers are not reachable (other pods are reachable)

this is an odd one. I've setup my K8s cluster, 1 master and 1 worker. It uses calico as cni, and everything looks to be working as expected (I'm able to deploy pods, services, etc). I'm able to reach ...
user avatar
  • 119
0 votes
1 answer
60 views

Unable to see computers on site to site VPN

Windows server: 192.168.0.10 Linux server: 192.168.0.1 Network printer: 192.168.0.30 192.168.0.0/24 site to site with 192.168.1.0/24 On a computer on second subnet (192.168.1.32) I can ping the Linux ...
user avatar
0 votes
0 answers
103 views

Could an incompatable Xeon processer cause only two of four RAM slots to be used?

Issue With everything installed correctly, only two of my four RAM sticks are being recognized with the BIOS. I checked the QVL for the motherboard, and the Xeon E5-2628L v3 that I am using is not ...
user avatar
  • 135
0 votes
0 answers
32 views

All unregistered domains are being redirected to the same IP. What does this mean?

Whenever I make a request to an unregistered URL, I receive a 301 response code and I'm redirected to a specific IP. For example, in response to http GET http://dsfijewijfeif.com I get: HTTP/1.1 301 ...
user avatar
  • 1
5 votes
1 answer
5k views

What would be causing "PowerShell.exe" to hang upon opening on multiple systems and/or how can I troubleshoot it?

What would be causing "PowerShell.exe" to hang upon opening on multiple systems? I've waited for over 60 minutes, but it never fully starts. All it does is show the blue shell window with the ...
user avatar
  • 51
0 votes
1 answer
67 views

Troubleshooting "traps: proces_name[pid] general protection" memory issue on Linux

I'm trying to troubleshoot a memory issue on one of my servers. Some time ago a daemon my company is developing crashed with segmentation errors. All would be somewhat fine, but seconds later other ...
user avatar
0 votes
0 answers
35 views

How to troubleshoot internet down every day?

Every day the server is unreachable and I need to unplug and replug it in. I cannot ping it and all web services are down. After a reboot the internet is back on again. There are no cronjobs fail2ban ...
user avatar
  • 113
1 vote
1 answer
119 views

how to man-in-the-middle blocking/intercepting/editing all network traffic going to a single cabled device and a server

I need to completely block and intercept and alter all packets going between two devices. possibly i need to isolate one device and block/intercept/edit ALL traffic going to and from it if i cannot ...
user avatar
1 vote
1 answer
1k views

HP ML350 G6 will not power on

I have no lights on MB or back of power supply. I have replaced power supply and added a redundant power supply. I replaced PD board or backplane whatever you want to call it. Still same result. ...
user avatar
0 votes
1 answer
192 views

How do I troubleshoot possible drive issues on ESXi 6.7?

I have a Dell Poweredge R630 with 4 drives in a RAID. I'm not sure if it's RAID 10 or RAID 5 because I didn't order or set up the server originally and I'm just the default network admin, it's not my ...
user avatar
0 votes
1 answer
41 views

Unable to start mariadb

My ubuntu server's mariadb service was down and from running "journalctl -xe" I could see that the error must be caused by courrupted files so i append the following entry to my /etc/mysql/my.cnf file ...
user avatar
3 votes
1 answer
1k views

Troubleshoot random server freezes without log entries

We are experiencing a very particular and unique problem on our C# application which is running under .NET framework 4.7.2, in kiosk mode on Windows 10 Operating System that runs on a Lenovo ...
user avatar
0 votes
1 answer
1k views

mysqldump cron job runs in terminal but not cron tab

I have this cron job, /usr/bin/mysqldump -u username -p'password' MyDatabase > /backup/CronBackup/MyDatabaseBackup.sql &>/backup/CronBackup/cronBackupLog.log I have been through this page: ...
user avatar
1 vote
0 answers
36 views

Diagnosing increase in traffic hitting a Django web application

This question is about diagnosing the causes of elevated network traffic in an internet-facing web application. Background: The web application in question is a Django-based forum where users upload ...
user avatar
  • 1,933
0 votes
1 answer
199 views

iptables rejects vpn client by port

Here is my iptables commands: sudo iptables -F sudo iptables -A INPUT -p tcp -s 109.123.74.85 --dport 27000 -j ACCEPT sudo iptables -A INPUT -p tcp -s 188.170.80.4 --dport 27000 -j ACCEPT sudo ...
user avatar
2 votes
1 answer
136 views

How to troubleshoot internal DNS resolution (Windows DNS server) pointing to a local server with a static internal IP address

To better explain the set up I have a Debian server in a private network with a static IP. There is a windows AD server that resolves DNS for clients internally. A domain name is already registered ...
user avatar
  • 123
0 votes
1 answer
789 views

nginx workers stack at 100% usage after X random days

I am facing a strange incident, under which my two nginx workers suddenly get stack at 100% of CPU usage after a random number of days and at the same web traffic, under which they are behaving fine ...
user avatar
1 vote
0 answers
1k views

AD domain rename problems, can't add server of the same name

I have inherited an active directory domain controller, and after adding a number of servers I found that I couldn't add a server with a specific name. I since found out the admin who built the ...
user avatar
  • 1,120
0 votes
0 answers
199 views

Diagnosing NFSv4 Authentication Issues

I've got a couple of NFSv4 shares (with Kerberos authentication). Most of the time they work quite well, but when there's an issue they can be a pain to fix. I put this down to them being quite ...
user avatar
1 vote
0 answers
953 views

How to diagnose UDP connectivity issues?

I have an OpenVPN connection which was initially over UDP. After some time I started to have serious hiccups when running ssh inside that tunnel. As seen from inside the tunnel, ssh packets were lost,...
user avatar
  • 3,317
0 votes
1 answer
98 views

How to interpret the debug output from Amavis->Spamassassin?

Could please someone explain how Spamassassin build the following strings: Oct 17 14:00:30 server amavis[29497]: (29497-02) SA dbg: uridnsbl: domain amazonaws.com in skip list, host sns.eu-central-1....
user avatar
  • 245
2 votes
2 answers
2k views

How to determine process which makes DNS Request? [duplicate]

I have a server on AWS, GuardDuty started send me notifications: *** "type":"Backdoor:EC2/C&CActivity.B!DNS", *** {"domain":"libcurl.so","protocol":"UDP","blocked":false} *** is querying a domain ...
user avatar
  • 245
1 vote
1 answer
37 views

Why does LAN stops working if switch is connected to two upfeeds?is [closed]

If I connect my switch to two upstream feeds from my ISP, my internal LAN stops functioning (see illustration below). What is it in the TCP/IP protocol that is disrupted to cause the above? ...
user avatar
1 vote
2 answers
1k views

Error: No space left on device: (deleted)/dev/zero

**** Hoster something changed on hypervizor but said, that nothing was changed. The problem is not on the server anymore... **** Could someone help me to solve the following problem: If I want to ...
user avatar
  • 245
0 votes
1 answer
3k views

Office 365 In-Place Hold preventing me from deleting user

I am using AD Connect to synchronize my on-premises Active Directory to our Office 365 tenant. I tried disabling a user from on-premises and then synchronizing to O365. However, it seems to have ...
user avatar
  • 1,094
0 votes
0 answers
40 views

Investigating night time shut downs

I have a Windows Server 2008 R2 install (AMD FX-4100 quad core, 32gb) is shutting down around 2:30 am every other night. I've updated the motherboard BIOS but that hasn't helped. I ran AUTORUNS.EXE ...
user avatar
  • 149
-1 votes
1 answer
107 views

Diagnose Sudden Slowness on Linux

I have two identical Linux laptops (Core™ i7-4810MQ with 32GB RAM) both running Ubuntu 16.04. Running seemingly any command on machine 2 takes about 4-12 times as long as on machine 1, depending on ...
user avatar
1 vote
1 answer
259 views

Periods of high packet loss, two ethernet cables plugged into TWC modem

A small business for which I am the system administrator has been experiencing intermittent internet dropouts. There seems to be no pattern to the dropouts — sometimes there is nothing for a week, and ...
user avatar
1 vote
1 answer
2k views

Strange behavior from App-V virtualized application - can't start new instance until all others are closed

I first must apologize for the vagueness of this. It is rather hard to pin down, which is why I turn to posting this. The environment is Windows 2012 R2 Citrix 7.16 servers, multi-tenant (which is ...
user avatar
  • 1,283
0 votes
1 answer
1k views

Updating a Zone File - Adding CNAME records - How to troubleshoot/where have I gone wrong?

I apologize in advance for this newbie question. I've resorted to asking because I can't seem to find enough closely-related queries* on this network or elsewhere, and the BIND 9.9 ARM is not exactly ...
user avatar
0 votes
1 answer
556 views

SSRS Subscription fails, Server Response 4.4.1

I have an SSRS server that processes many subscriptions on a daily basis. I have just become aware of this, so I don't know if it is a new or an old problem, but only one subscription has been ...
user avatar
-1 votes
1 answer
208 views

How to diagnose end user DNS problems with my domain? [closed]

I work for a small part of a large organization that has been on the internet since dinosaur days (pre-CIDR). I'm confident our DNS is properly configured, but a tiny fraction (<1%) of our remote ...
user avatar
  • 161
-1 votes
1 answer
758 views

What to do with trailing slash in $HOME on CentOS?

I have a little project server sandbox running CentOS. Setting up a new server package, I realized I needed to add new directory to the path and I found $HOME has a trailing slash for the main user. ...
user avatar
  • 311
0 votes
1 answer
734 views

Cisco C220 M3 Doesn't Recognize HBA, SSD

I am attempting to set up a Cisco C220 M3 blade server for a company and have been running into issues with the hard driver controller(s) that the machine has. The intent is to have vmWare ESXi ...
user avatar
0 votes
2 answers
851 views

Part of LAN network connected to 1 switch freezes up periodically

I'm managing an office network which is spread across 2 buildings. (see network setup below) In building 2, we are getting a problem where the network slows down and then completely cuts off. The ...
user avatar
  • 173

1
2 3 4 5
7