Following announcement of ProFTPD version 1.3.5a CentAlt rpm has been updated.
Following announcement of ProFTPD version 1.3.5a CentAlt rpm has been updated.
After upgrading Postgres to version 9.4 in VM using container service failed to start with following message:
/etc/init.d/postgresql start [....] Starting PostgreSQL 9.4 database server: main[....] The PostgreSQL server failed to start. ... FATAL: could not open shared memory segment "/PostgreSQL.1804289383": Permission denied ... failed!
Quick search pointed to lack of shared memory, but I had more than enough.
It turned that fix is to change dynamic_shared_memory_type from posix to none.
vi /etc/postgresql/9.4/main/postgresql.conf ... dynamic_shared_memory_type = none ...
and I was able to start
/etc/init.d/postgresql start [ ok ] Starting PostgreSQL 9.4 database server: main.
If you installed CentOS 7 minimal you might see following error message when you try to use ifconfig to see your ip address:
[root@localhost ~]# ifconfig -bash: ifconfig: command not found
If you search for the package it is in net-tools package
[root@localhost ~]# yum search ifconfig Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: centos.mirror.iweb.ca * extras: mirror.csclub.uwaterloo.ca * updates: mirror.csclub.uwaterloo.ca =================================================================== Matched: ifconfig ==================================================================== net-tools.x86_64 : Basic networking tools
In case you do not want to install additional package and simply to see your ip address you can use ip addr command
[root@localhost ~]# ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 08:00:27:eb:6b:89 brd ff:ff:ff:ff:ff:ff inet 10.0.0.15/24 brd 10.0.0.255 scope global dynamic enp0s3 valid_lft 85578sec preferred_lft 85578sec inet6 fe80::a00:27ff:feeb:6b89/64 scope link valid_lft forever preferred_lft forever
To install ifconfig
[root@localhost ~]# yum install net-tools Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: centos.mirror.iweb.ca * extras: mirror.csclub.uwaterloo.ca * updates: mirror.csclub.uwaterloo.ca Resolving Dependencies --> Running transaction check ---> Package net-tools.x86_64 0:2.0-0.17.20131004git.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ========================================================================================================================================================== Package Arch Version Repository Size ========================================================================================================================================================== Installing: net-tools x86_64 2.0-0.17.20131004git.el7 base 304 k Transaction Summary ========================================================================================================================================================== Install 1 Package Total download size: 304 k Installed size: 917 k Is this ok [y/d/N]: y Downloading packages: net-tools-2.0-0.17.20131004git.el7.x86_64.rpm | 304 kB 00:00:00 Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : net-tools-2.0-0.17.20131004git.el7.x86_64 1/1 Verifying : net-tools-2.0-0.17.20131004git.el7.x86_64 1/1 Installed: net-tools.x86_64 0:2.0-0.17.20131004git.el7 Complete!
and then you can use it
[root@localhost ~]# ifconfig enp0s3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 10.0.0.15 netmask 255.255.255.0 broadcast 10.0.2.255 inet6 fe80::a00:27ff:feeb:6b89 prefixlen 64 scopeid 0x20<link> ether 08:00:27:eb:6b:89 txqueuelen 1000 (Ethernet) RX packets 11316 bytes 14098176 (13.4 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 3224 bytes 264337 (258.1 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 0 (Local Loopback) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
phpMyAdmin is a tool written in php intended to handle administration of MySQL servers over the web interface.
When trying to import large SQL dumps you might see following message:
Maximum execution time of 300 seconds exceeded
If you are running on local host or host you manage the solution is to edit \phpmyadmin\libraries\config.default.php file and change
$cfg['ExecTimeLimit'] = 300;
$cfg['ExecTimeLimit'] = 0;
This will allow you to remove the limit.
In case you do not have access to configuration file (and your provider does not want to apply this change even if you ask nicely) only solution is to split one large file to several smaller files using text editor and add them one by one.
Note: The size of the file varies from host to host and should be determined by the method of trial and errors.
Recently I’ve upgraded ZFS on Linux to 0.6.3 on my CentOS 7 server.
After reboot my pool was not available and I was only capable to force the import.
In the logs I had:
Oct 24 10:26:33 hs kernel: SPL: using hostid 0x00000000 Oct 24 10:26:34 hs zpool: cannot import 'tank': pool may be in use from other system Oct 24 10:26:34 hs zpool: use '-f' to import anyway Oct 24 10:26:34 hs systemd: zfs-import-cache.service: main process exited, code=exited, status=1/FAILURE Oct 24 10:26:34 hs systemd: Failed to start Import ZFS pools by cache file. Oct 24 10:26:34 hs systemd: Unit zfs-import-cache.service entered failed state.
After quick search on the Internet I found that I’m not alone.
Original thread is here: https://github.com/zfsonlinux/zfs/issues/2575.
The fix for me was to create hostid:
dd if=/dev/urandom of=/etc/hostid bs=4 count=1
If you are administering nix server you’ve probably noticed that root account is used by default for many system emails.
If you did set email forwarding you already received them, but in case you did not the folder continues to grow and it can get thousands of emails.
Cleaning all those email via mail client is at least time consuming.
If you do not want any of those messages you can speedup the process by typing following command:
With my new server I wanted to install LAMP stack so I can test WEB applications locally. Just to note that in CentOS 7 it is not exactly classic LAMP (Linux Apache MySQL PHP), but new LAMP ( Linux Apache MariaDB PHP).
As in most package oriented OS Installation of LAMP on CentOS 7 is generally simple and consist of running following commands:
0. Update you system and add EPEL repo
sudo yum update
sudo yum localinstall --nogpgcheck http://download.fedoraproject.org/pub/epel/beta/7/x86_64/epel-release-7-0.2.noarch.rpm
1. Install packages
sudo yum install httpd mariadb-server mariadb php php-mysql php-gd php-pear php-xml php-bcmath php-mbstring php-mcrypt php-php-gettext
If you need additional php modules just add them.
2. Enable services
sudo systemctl enable httpd.service
sudo systemctl enable mariadb.service
3. Start services
sudo systemctl start httpd.service
sudo systemctl start mariadb.service
4. Secure MariaDB installation
5. Open firewall ports
sudo firewall-cmd --permanent --add-service=http
sudo firewall-cmd --permanent --add-service=https
sudo firewall-cmd --reload
5. Test components
To test PHP and apache installation create new php script
Put following code inside:
your ip addres/phptest.php with a browser.
6. Install phpMyAdmin
sudo yum install phpMyAdmin
7. Configure phpMyAdmin to allow connections
Comment out curent
<directory /usr/share/phpMyAdmin> AllowOverride none Options none Require all granted </directory>
sudo systemctl restart httpd.service
your ip addres/phpMyAdmin
You should be able to login with you root account
After I’ve created my home server I’ve tried to change it’s host name by going to /etc/sysconfig/network. For my surprise it was empty. Then I’ve recalled that in version 7 CentOS started using systemd. Hence the location changed.
New place to edit is /etc/hostname
The inconvenience of editing file directly is that system reboot is required to apply the change.
Alternative method is to use Network Manager tool by invoking nmtui.
and then execute:
systemctl restart systemd-hostnamed
You can type hostname to validate the change.
CentOS 7 is out and I wanted to test it on real hardware. Unfortunately most of current methods to transfer bootable ISO to USB key in MS windows environment do not work (see quote below) or boots, but does not recognize installation media in case of Fedora LiveUSB Creator (suggested in RHEL 7 Installation guide).
CentOS 7 installer image has a special partitioning which, as of July 2014, most Windows tools do NOT transfer correctly leading to undefined behavior when booting from the USB key. Applications known (so far) to NOT work are unetbootin and “universal usb installler”.
After applying method of trial and errors I’ve discovered that best tool to transfer ISO to USB key is Win32DiskImager.
Note: Writing ISO image to USB drive overwrites all data on the drive.
Put the path to downloaded ISO image in image file(1), choose USB key drive letter (2) and press write(3).
Now you are ready to boot and install from your USB key.
In case you need to disable IPv6 and cannot afford to restart here are the commands to quickly do it for CentOS:
echo "net.ipv6.conf.default.disable_ipv6 = 1" >> /etc/sysctl.conf
echo "net.ipv6.conf.all.disable_ipv6 = 1" >> /etc/sysctl.conf