yum update Loaded plugins: fastestmirror, ovl Determining fastest mirrors Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=container error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error" One of the configured repositories failed (Unknown), and yum doesn't have enough cached data to continue. At this point the onl........

It may appear to be an Xorg or lightdm/gdm/mdm error but in reality for many users with this issue, it's a driver conflict and issue. I had a system that had two GPUs, an Intel and Nvidia GPU. The only thing that got it working was to remove the nouveau driver and blacklist it so it never came back, then the Intel GPU works fine without these issues. Solution sudo rmmod nouveau add nouveau/other driver to blacklist edit th........

Aug 10 01:11:54 mailserver postfix/smtp[6180]: 020AE17C2BD1: to=, relay=none, delay=0.29, delays=0.28/0/0/0, dsn=5.4.4, status=bounced (Host or domain name not found. Name service error for name=gmail.con type=A: Host not found) A user complained that their e-mails weren't being delivered but they actually made a small typo and used gmail.con so it wasn't working as expected of course........

Normally the below would indicate a failing or failed drive. In this case the SATA port was unplugged and sometimes the Linux kernel/motherboard even with AHCIjust don't play nice and can't handle it. What happened is Iplugged in a new drive after removing another one. However the log shows that after the old drive was plugged in the Linux kernel kept complaining thinking the drive was there but not responding properly. This continued even with reseating........

The solution is simple but strange, if you copy your /var/lib/mysql directory to another server and think it will work, be sure to check if you have /var/log/mysql and binary log files. If you do, the server will not work and will give you errors like below and crash without the proper log files. UPDATE user SET password=password("newpass") WHERE user='root'; flush privileges; ERROR 2013 (HY000): Lost connection to MySQL server durin........

PHP5 Centos 6 displays part of code from PHP file for some scripts Solution edit /etc/php.ini change short_open_tag = Off to: short_open_tag = On Then restart Apache and it should be resolved (assuming the scripts failing used ) ........

Here's a proven example of what a bad hard drive can do, it was technically functioning OKin a RAID array but the system became extremely low and the load become high and IOWAIT was even higher and I always thought it was a bad application. The truth is that this failing 1TBHitachi has slowly gotten worse and caused huge slowdowns, (eg. 100% load on Thunderbird waiting for e-mails to load etc..). After swapping it out, tabs change instantly, emails are not lagged, and........

I like dd, although it only reads it, usually a read test of the entire disk will uncover if your hard drive is bad in some parts. This is a good thing to do at least once a month, a lot of times bizarre program behavior, laginess and crashing/unnmounting problems etc.. are due to a failing disc and SMART won't know it or indicate a problem: We must also remember there's never a guarantee, I've found that ever since we moved to larger and more platters per drive with 1TB drives........

Seagate Inventory/Firmware Check I heard about this issue a long time ago but never looked into it. I figured I wasn't affected since my 500GB drives were running for so long. I've been using Seagate's since 2002 and to this day all of the drives I have are alive from Seagate. *Update the bad news is that I realize one of my 500GB's is about to die, it's not even a year old, but is also not affected by the recall according to Seagate! Seagate Inventory/Firm........

A VPS Server I had just wasn't working right, code that I migrated there just wasn't working. For example, it kept telling me the connection to the database was unsuccessful, halfway through iterating through results it already had. Then I realized it wasn't my code. Ichecked my /proc/user_beancounters and found this: cat /proc/user_beancounters Version: 2.5 uid resource held maxheld barrier limit failcnt........

At this time we can't resolve Enom's website and all DNS requests to their 4 primary name servers are failing, although the hostnames themselves still resolve: Name Server: DNS1.NAME-SERVICES.COM Name Server: DNS2.NAME-SERVICES.COM Name Server: DNS3.NAME-SERVICES.COM Name Server: DNS4.NAME-SERVICES.COM Name Server: DNS5.NAME-SERVICES.COM You would really think Enom, bein........