systemd is like the service manager for your Centos and other modern Linux distributions (including Debian/Mint/Ubuntu) allows you to enable services, stop them, restart them, check their status and even reboot your system.
The key commands or arguments you will use with systemctl are the following:
list-units [PATTERN...] List loaded units
The commands below will help you reset any mysql user password.
update user set password=PASSWORD('thenewpass') where User='theusername';
The first line says to use the "mysql" database which contains all the user info.
the second update line sets the new password "thenewpass" for the u........
This is a 8TB Seagate external USB 3.0 device apparently newer kernels use a module called "UAS" instead of "USB Storage" which causes issues as a lot of devices are not properly supported in UAS mode by the kernel driver. The solution some say is to disable UAS specifically for your USB device but I'd rather just disable UAS altogether.
Solution blacklist UAS: *do not do this it does not work and just causes your USB 3.0........
These errors believe it or not are simply because of not being the root user or running with sudo! However if you didn't know to try as root you'd think there was a problem with your burner or disc Essentially it looks like without root you cannot send the required scsi commands to continue writing. I think cdrecord should have built-in tests or safeguards to see if it has the permissions to run the required commands.
I guess for more advanced users the idea is simila........
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';
ERROR 2013 (HY000): Lost connection to MySQL server durin........
I created a new partition table on a newly plugged in device and it caused fdisk to hang (even force kill does not work). It also may be a bad drive or some other issue because fdisk -l hangs after the first 2 HDDs (totaly of 8 HDDs on this system):
[1232879.903596] INFO: task fdisk:27176 blocked for more than 120 seconds.
[1232879.903607] Tainted: P &nbs........
I've got one of these for testing projects from work at home and got more than I bargained for with the time I've spent on it due to the storage handing/Perc 6/i cards.
My particular model came with the following:
2U Rack Mount Server with Rails
2xOpteron 2373 EE (Quad Core, there is a 6-core version that can be found at times)
2 x 250GB Seagate SATA
2 x Dell Perc 6/i (horrible and a nightmare to work........
At first it was configured as a RAID 0, then I deleted the Virtual Disk Group.
I thought both drives would be shown and detected in Linux as sda and sdb but it actually shows nothing.
To make them work you have to hit Ctrl+R before the system boots (when prompted) and create a Virtual Disk Group. In my case I created each one as RAID 0 (with a single drive only) as I just wanted JBOD but there is no such option or default in these Dell Pe........
mysqldump: Couldn't execute 'show create table `general_log`': SHOW command denied to user 'user'@'localhost' for table 'general_log' (1142)
One of my clients almost found out the hard way, here is an unlikely situation that happened.
1.) Years ago the client had another VPS to which they backed up a BLOG nightly to an .sql file, what they forgot is that the file also contained all databases (they used the --all-databases option but forgot). So imagi........
ERROR 1146 (42S02): Table ‘mysql.servers’ doesn’t exist
This happened to me on a system running Centos with the REMI repo and a new version of Mysql 5 (which the official Centos/RHEL does not support on version 5).
The solution is just to run this program "mysql_upgrade", after that flush privileges will work.
don't delete /var/lib/mysql/ib_logfile0 or ibdata1 or mysql won't restart
I didn't realize they were internal and not part of replication like the relay files!
/usr/libexec/mysqld: ready for connections.
Version: '4.1.22-log' socket: '/var/lib/mysql/mysql.sock' port: 3306 Source distribution
110127 16:31:00 [Note] /usr/libexec/mysqld: Normal shutdown
110127 16:31:00 InnoDB: Starting shutdown...........
One note is to secure MySQL, I don't know for sure but I believe you could login to MySQL remotely with no password during this operation (I'm not sure, maybe it doesn't accept blank passwords but I firewall MySQL port anyway and recommend you do the same).
First edit /etc/my.cf
Under the [mysqld] field add the following line somewhere:
Now restart mysql: service mysql restart or on Debian sty........
This was unbelievable how much the Xen kernel slows things down, keep in mind both tests were done on the hostnode, one was with the Openvz-Xen hybrid kernel and the other was just OpenVZ. You can see the performance difference is nearly 300% better when not using the Xen kernel.
OpenVZ-Xen Kernel Test Results (I was wondering what was wrong/so slow with my Core i5!)
# # # # # # &n........
Here are the results, it is Sempron 3000+ AMD Mobile, 500Gig HDD, 512MB RAM with shared ATI Radeon graphics.
# # # # # # # ##### ###### # # #### # #
# # ## # # # #&nb........