Josh Wieder

Comcast is my current home ISP. Over the last year, I've had a ton of problems with them filtering all sorts of legitimate (outbound) traffic . The latest fun times I've had is the random dropping of SSH connections on both standard (22) and non-standard TCP ports. This occurred while I was running a `yum update` on one of my servers and I hadn't used ` nohup ` or ` disown ` to allow the processes I had spawned to continue to run. By the time I had got a VPN connection up and running, the yum process had been terminated, which in turn caused yum's database to become corrupt. How can you tell that your server's yum database is corrupt? Running yum will generate this vaguely-terrifying error: # yum update error: rpmdb: BDB0113 Thread/process 4498/140039588845376 failed: BDB1507 Thread died in Berkeley DB library error: db5 error(-30973) from dbenv->failchk: BDB0087 DB_RUNRECOVERY: Fatal error, run database recovery error: cannot open Packages index using db5...

A few of my Red Hat servers run cron jobs to check for updates. starting yesterday (Thursday October 1st, 2015) at around 3PM I encountered 503 unavailable errors when attempting to contact a Fedora Project URL that hosts the metalink for the  rhui-REGION-rhel-server-releases repository - a core RHEL repository for EC2. Could not get metalink  https://mirrors.fedoraproject.org/metalink?repo=epel-7&arch=x86_64  error was 14: HTTPS Error 503 - Service Unavailable 3 hours later or so, the URL began responding again, but the problems remained. `yum` now reports corrupted update announcements from the repo: Update notice RHSA-2014:0679 (from rhui-REGION-rhel-server-releases) is broken, or a bad duplicate, skipping. You should report this problem to the owner of the rhui-REGION-rhel-server-releases repository. Update notice RHSA-2014:1327 (from rhui-REGION-rhel-server-releases) is broken, or a bad duplicate, skipping. Update notice RHEA-2015:0372 (from rhui-REG...

When installing the vulnerability scanner application Nikto/Nikto2 using yum with RedHat Enterprise Linux 7 or CentOS 7 or even Scientific Linux 7, the odds are good that you will encounter some irritating problems. Namely, the installation will fail while requiring a dependency that appears to not exist for the version of linux you are using. Fun! So you probably think you are safe if you install OpenVAS , a prepackaged suite of security utilities that includes Nikto as a plugin. But you would be wrong! Installing OpenVAS from an RPM will succeed, and everything will look fine, until you try to use Nikto within OpenVAS, which will result in a fatal error. Nikto is included in the Extra Packages for Enterprise Linux/EPEL yum repository all recent versions of RedHat linux, which is part of the Fedora Project. While it contains third party applications, it is not a third party repository like RPMFusion or Atomicorp . I have only very rarely had problems with the EPEL yum repo, and t...

I have seen indications of periodic connectivity issues impacting Amazon's EC2 Cloud Computing architecture. Personally, I have encountered issues with connecting to Amazon's Yum repository hosts from EC2 instances. Amazon has published Outage notifications of brief connectivity and DNS failures impacting US-EAST-1 Availability zone between October 2nd and October 4th. However, my EC2 instances are within the US-WEST-2 Availability zone and I am experiencing issues today, October 4th 2014 at approximately 11:30 AM EST. For example: # yum provides seinfo Loaded plugins: amazon-id, rhui-lb epel/x86_64/filelists_db         | 4.7 MB  00:00:01 rhui-REGION-rhel-server-optional/7Server/x86_64/filelists_db    | 3.2 MB  00:00:00 https://rhui2-cds01.us-west-2.aws.ce.redhat.com/pulp/repos//content/dist/rhel/rhui/server/7/7Server/x86_64/os/repodata/e5ee2c196ee6525998525a2bf74bb40608dce199-filelists.sqlite.bz2: [Errno 14]...

So you've just run a barebones installation of CentOS 6, and you run a host command to check DNS resolution and you get the following: whois: command not found By default the barebones CentOS installation lacks even the most basic network diagnostic tools. Use yum to install the following packages to get a few basic tools back on your server: yum install bind-utils  (installs nslookup and host) yum install jwhois (installs whois)