Tag Archives: backup

Dumping multiple mysql tables at once

Could happen to have a mysql database with a lot of tables and we want dump all of them, but we also want to make the logical dump process faster. Some of you could say that mydumper is the solution. It could be. But what if we don't have the permission to install it or whatever?

Let's say we have these tables and we need to dump all of them:

[codesyntax lang="bash"]

MariaDB [database]> show tables like "objects_2015%";
| Tables_in_xxxxxxxxxx_logs (objects_2015%)     |
| objects_2015_12_01                            |
| objects_2015_12_02                            |
| objects_2015_12_03                            |
| objects_2015_12_04                            |
| objects_2015_12_05                            |
| objects_2015_12_06                            |
| objects_2015_12_07                            |
| objects_2015_12_08                            |
| objects_2015_12_09                            |
| objects_2015_12_10                            |
| objects_2015_12_11                            |
| objects_2015_12_12                            |
| objects_2015_12_13                            |
| objects_2015_12_14                            |
| objects_2015_12_15                            |
| objects_2015_12_16                            |
| objects_2015_12_17                            |
| objects_2015_12_18                            |
| objects_2015_12_19                            |
| objects_2015_12_20                            |
| objects_2015_12_21                            |
| objects_2015_12_22                            |
| objects_2015_12_23                            |
| objects_2015_12_24                            |
| objects_2015_12_25                            |
| objects_2015_12_26                            |
| objects_2015_12_27                            |
| objects_2015_12_28                            |
| objects_2015_12_29                            |
| objects_2015_12_30                            |
| objects_2015_12_31                            |
74 rows in set (0.00 sec)


Dumping, let's say, 6 tables in parallel will speed up the dump process.
Note: Too many mysqldump instances could overload the server and make the dump process slower (if the server is a production server this could have quite an impact on the performance).

We need the list with all the commands we need to execute:

[codesyntax lang="bash"]

for i in $(mysql -h host -uuser -ppassword database -Bsqe "show tables like \"objects_2015%\""); do echo "mysqldump -h host -uuser -ppassword --add-drop-table --quick --quote-names --disable-keys --extended-insert database $i | gzip > /path/to/backup/$i.sql.gz"; done > /tmp/things_to_do/tables.txt


Start the dump process:
[codesyntax lang="bash"]

parallel -j 6 < /tmp/things_to_do/tables.txt


How to clone a running Linux system over network using netcat

This is a short but potentially extremely handy guide to ghosting one Linux box to another (or simply making a full backup of a desktop/server).

On the target machine:
[codesyntax lang="bash"]

nc -p 2222 -l | bzip2 -d | dd of=/dev/hdb


On the source machine:
[codesyntax lang="bash"]

bzip2 -c /dev/hda | nc 2222



  • please be VERY careful about IPs, devices and ports.
  • after completion of dd command you have to run fsck on target partitions

Creating backups of running VMs in XenServer

With XenServer it is possible to create backups of VMs, even if they are running. The process is as follows:

Search for the uuid of the VMs to backup

First look for the uuid of the VMs to backup. We don’t want to backup the control domain itself, so we add is-control-domain=false to the vm-list command:
[codesyntax lang="bash"]

xe vm-list is-control-domain=false


Create a snapshot of each (running)

Now we create a snapshot of the VMs we want to backup, replacing the uuid one by one with the ones we found with the previous command. Also replace the name of the snapshot if desired:
[codesyntax lang="bash"]

xe vm-snapshot uuid=8d6f9d81-95b5-2ffb-4ecc-b5e442cc5c22 new-name-label=gb-r7n2-snapshot


This command has a return value: the uuid of the created snapshot. Then we transform the snapshot into a VM to be able to save it to a file, replacing uuid with the return value of the previous command:
[codesyntax lang="bash"]

xe template-param-set is-a-template=false ha-always-run=false uuid=4efd0392-8881-176c-012e-a56e9cb2beed


Save the snapshot to file

In the next step we save the snapshot to a file, replacing uuid with the snapshot uuid and providing a meaningful filename:
[codesyntax lang="bash"]

xe vm-export vm=4efd0392-8881-176c-012e-a56e9cb2beed filename=gb-r7n2-snapshot.xva


Remove the created snapshot

In the final step we delete the snapshot:
[codesyntax lang="bash"]

xe vm-uninstall uuid=4efd0392-8881-176c-012e-a56e9cb2beed force=true


Source: http://www.jansipke.nl/creating-backups-of-running-vms-in-xenserver/