If you are running a local DNS server like named/bind and don't want to use the ISPsupplied DNS servers that are announced via a DHCP request (using dhclient) then the solution is simple.
The reason should be obvious, but normally running your own DNS server will provide a more reliable, and fast DNS response and you won't have to worry about filtering as much (unless your upstream filters or proxies outgoing DNS requests).
This article about migrating to a CentOS 7 /8 RAID mdadm array has a lot of info but I wanted to focus specifically on what newer versions of CentOS 7 require to boot mdadm and what changes are necessary on CentOS 7.8+
CentOS 7 / 8 mdadm RAID booting requirements
This assumes you are chrooting into an existing install or using it to get a new deployment ready. However, these steps can........
By default at least on Centos 7 nfs only allows 8 connections and starts 8 nfsd daemons.
To fix this edit this file:/etc/sysconfig/nfs
Edit the line "RPCNFSDCOUNT" (uncomment it so it looks like this:
In the example above we are setting 30 nfsd daemons to run (or in other words 30 connections are possible this way).........
Almost always the reason will be that the php.so file is missing but also that php.conf is misconfigured.
In the problem machine it is actually PHP7 installed so if you reference PHP5 of course things wil be broken!
Take for example here:
# PHP is an HTML-embedded scripting language which attempts to make it
# easy for developers to write dynamica........
Just a note before you do this you should have a sure, guaranteed way into the system such as local, KVMor preferably publickey making bruteforce SSH absolutely impossible since there is no password to bruteforce and even if someone knew the password they wouldn't be able to login except from the local console (presumably you should make sure no one unauthorized has physical access).
1. Edit /etc/ssh/sshd_config
Find the section like this:........
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=6&arch=x86_64&repo=os error was
12: Timeout on http://mirrorlist.centos.org/?release=6&arch=x86_64&repo=os: (28, 'Operation too slow. Less than 1 bytes/sec transfered the last 30 seconds')
Error: Cannot find a valid baseurl for repo: base
You would think this should be fine and simple like using a proxy with most other software?
For the first two entries comment out #mirrorlist and uncomment #baseurl and then it worked
openvz yum problem Centos 6.5 cannot find file on mirror:
Loaded plugins: fastestmirror
Determining fastest mirrors
* openvz-kernel-rhel6: mirrors.ustc.edu.cn
* openvz-utils: mirrors.ustc.edu.cn
This booting error is because the Xen PV guest image uses the Xen kernel, this is not compatible with anything but a host running a Xen kernel.
I did a kpartx -av virtual.img and then it created some partitions that showed up in fdisk.
I mounted it and did a chroot into it and removed the xen kernel and installed a normal kernel but Xen still shows the same kernel in Grub (only the Xen one).
This is strange but it seems like this Xen PV guest has some sort of hidden or........
*Remember to restart spamassassin after all of this.
tar -zxvf dcc.tar.Z
#enable DCC, uncomment the line that disables it near the top
Create Cert & Key:
openssl req -new -x509 -nodes -days 1530 -out server.crt -keyout server.key
chmod 700 /etc/mailssl
cp server.* /etc/mailssl
Postfix SSL config
smtpd_tls_cert_file = /etc/mailssl/server.crt
smtpd_tls_key_file = /etc/mailssl/server.key
To make smtps w........
genuine.com/IN: loading master file genuine.com.zone: file not found
_default/genuine.com/IN: file not found
I always found it silly that no one really talks about this and apparently many like me and even control panels like Plesk were still using hard paths. I always thought "why can't I just specify the name of the zone file and have bind find it". Surely the default search path must be /var/named or somewhere else but there is no such thing.........
I wasted a lot of time wondering why I could never find those packages.
Check the /etc/yum.conf file and at the bottom look for the "exclude=" line.
Below is what I found in mine
exclude=apache* httpd* mod_* mysql* MySQL* da_* *ftp* exim* sendmail* php* bind-chroot*
Just remove those entries or uncomment that line and you'll get access to the missing applications.........
Warning: get_browser(): browscap ini directive not set.
Solution is to edit /etc/php.ini
browscap = extra/browscap.ini........
Icouldn't understand why on one system it took a few minutes to get the SSHlogin prompt when connecting to other systems. The other systems all had the UseDNS parameter set to no, which almost always resolves the login prompt delay.
The reason is Ubuntu and perhaps Debian and other distributions /etc/nsswitch.conf file
Edit yours to have the "hosts" line like so (notice that files and dns are the primary resolution choice........