Arquivo mensal 29 de junho de 2017

Eu queria fazer o backup de alguns arquivos no Gmail, mas depois de juntá-los num tar.gz, o arquivo ficou grande demais para mandá-lo por email. Resolvi o problema dividindo o arquivo em partes menores e mandando-as individualmente.

Antes de mais nada, vamos juntar todos os arquivos em um tar. O ideal é que você crie uma pasta antes, pois quando for descompactar, os arquivos não serão jogados no diretório em que você está trabalhando, mas sim dentro dessa mesma pasta.
$ mkdir backup

Agora copie todos os arquivos que você quer fazer o backup para essa pasta. Se quiser, pode criar novas pastas dentro dessa.
$ cp arquivo1 arquivo2 arquivo3 ... backup

Depois disso, criaremos o tar. Você pode simplesmente criá-lo, ou também compactá-lo com o gzip ou o bzip2. Existem outras opções também, mas essas são as mais comuns. O bzip2 compacta melhor, mas é um pouco mais lerdo.
$ tar -cvf backup.tar backup # sem compactação
$ tar -zcvf backup.tar.gz backup # gzip
$ tar -jcvf backup.tar.bz2 backup # bzip2

Pode ser que você queira ver de que tamanho ficou o tar e ver se vai precisar dividi-lo ou não.
$ ls -lh | grep backup

Para dividi-lo, usaremos o split. No Archlinux ele vem no pacote coreutils, então é praticamente certeza que ele estará instalado. De maneira geral, ele será utilizado da seguinte forma:
$ split -b tamanho_individual arquivo_de_origem prefixo

Assim ele dividirá o arquivo_de_origem em arquivos de tamanho_individual (em bytes, ou você pode usar algum sufixo de tamanho) cada e com o nome prefixoaa, prefixoab, prefixoac… Eu usei algumas opções a mais, no fim ficou assim:
split -a 1 -b 9MB -d --verbose backup.tar.gz backup.tar.gz.

• O -a 1 modifica os identificadores após o prefixo, então ao invés de backup.tar.gz.aa, eu terei backup.tar.gz.a.
• O -d usa números no lugar de letras depois do prefixo, então no fim eu fiquei com backup.tar.gz.0, 1, 2, etc.(lembrando que se colocar 1 quando a contagem chegar em 9 ele para de fazer.)

Esse passo não é destrutivo. Em outras palavras, ele não apagará o arquivo original.

Para juntar usaremos o cat. Você pode primeiro reconstituir o arquivo original e então descompactá-lo, ou usar um pipe direto do cat para o tar. Vamos criar um novo diretório antes para evitar confusões com nome de arquivos antes.
$ mkdir tmp && mv backup.tar.gz.* tmp && cd tmp
$ cat backup.tar.gz.* > backup.tar.gz #reconstitui o arquivo e
$ tar -xvzf backup.tar.gz # descompacta o arquivo. ou
$ cat backup.tar.gz.* | tar -xvz # usa o pipe

Só se lembre de na hora de descompactar usar as opções certas, -z para gzip, -j para bzip2 e nada para apenas tar. Perceba também que no primeiro caso usamos -xvzf porque descompactamos um arquivo, no segundo não usamos o -f porque o tar está lendo do stdin.

adicionando pastas

urbackupclientctl add-backupdir -x -f -d /home
urbackupclientctl add-backupdir -x -f -d /root
urbackupclientctl add-backupdir -x -f -d /etc
urbackupclientctl add-backupdir -x -f -d /var

removendo pastas

urbackupclientctl remove-backupdir -d /backup

Introduction

ownCloud is a file sharing server that permits you to store your personal content, like documents and pictures, in a centralized location, much like Dropbox. The difference with ownCloud is that it is free and open-source, which allows anyone to use and examine it. It also returns the control and security of your sensitive data back to you, thus eliminating the utilization of a third-party cloud hosting service.

In this tutorial, we will install and configure an ownCloud instance on a CentOS 7 server.

Prerequisites

In order to complete the steps in this guide, you will need the following:

• A sudo user on your server: You can create a user with sudo privileges by following the CentOS 7 initial server setup guide.
• A LAMP stack: ownCloud requires a web server, a database, and PHP to function properly. Setting up a LAMP stack (Linux, Apache, MySQL, and PHP) server fulfills all of these requirements. Follow this guide to install and configure this software.
  • To take full advantage of all the features that ownCloud has to offer, make sure to install the following PHP modules: php-gd, php-intl, php-mbstring, php-process, and php-xml.
• An SSL certificate: How you set this up depends on whether or not you have a domain name that resolves to your server.
  • If you have a domain name… the easiest way to secure your site is with Let’s Encrypt, which provides free, trusted certificates. Follow the Let’s Encrypt guide for Apache to set this up.
  • If you do not have a domain… and you are just using this configuration for testing or personal use, you can use a self-signed certificate instead. This provides the same type of encryption, but without the domain validation. Follow the self-signed SSL guide for Apache to get set up.

Step 1 – Installing ownCloud

The ownCloud server package does not exist within the default repositories for CentOS. However, ownCloud maintains a dedicated repository for the distro.

To begin, import their release key with the rpm command. The key authorizes the package manager yumto trust the repository.

• sudo rpm –import https://download.owncloud.org/download/repositories/stable/CentOS_7/repodata/repomd.xml.key

Next, use the curl command to download the ownCloud repository file:

• sudo curl -L https://download.owncloud.org/download/repositories/stable/CentOS_7/ce:stable.repo -o /etc/yum.repos.d/ownCloud.repo

After adding the new file, use the clean command to make yum aware of the change:

• sudo yum clean expire-cache

Loaded plugins: fastestmirror
Cleaning repos: base ce_stable extras updates
6 metadata files removed

Finally, perform the installation of ownCloud using the yum utility and the install command:

• sudo yum install owncloud

When prompted with Is this ok [y/d/N]: message, type Y and press the ENTER key to authorize the installation.

. . .
Installed:
  owncloud.noarch 0:9.1.1-1.2                                                                                               

Dependency Installed:
  libX11.x86_64 0:1.6.3-2.el7              libX11-common.noarch 0:1.6.3-2.el7      libXau.x86_64 0:1.0.8-2.1.el7            
  libXpm.x86_64 0:3.5.11-3.el7             libpng.x86_64 2:1.5.13-7.el7_2          libxcb.x86_64 0:1.11-4.el7               
  libxslt.x86_64 0:1.1.28-5.el7            owncloud-deps-php5.noarch 0:9.1.1-1.2   owncloud-files.noarch 0:9.1.1-1.2        
  php-gd.x86_64 0:5.4.16-36.3.el7_2        php-ldap.x86_64 0:5.4.16-36.3.el7_2     php-mbstring.x86_64 0:5.4.16-36.3.el7_2  
  php-process.x86_64 0:5.4.16-36.3.el7_2   php-xml.x86_64 0:5.4.16-36.3.el7_2      t1lib.x86_64 0:5.1.2-14.el7              

Complete!

With the ownCloud server installed, we will move on to setting up a database for it to use.

Step 2 – Creating a MySQL Database

To get started, log into MySQL with the administrative account:

• mysql -u root -p

Enter the password you set for the MySQL root user when you installed the database server.

ownCloud requires a separate database for storing administrative data. While you can call this database whatever you prefer, we decided on the name owncloud to keep things simple.

• CREATE DATABASE owncloud;

Note: Every MySQL statement must end with a semi-colon (;). Be sure to check that this is present if you are experiencing an issue.

Next, create a separate MySQL user account that will interact with the newly created database. Creating one-function databases and accounts is a good idea from a management and security standpoint. As with the naming of the database, choose a username that you prefer. We elected to go with the name owncloud in this guide.

• GRANT ALL ON owncloud.* to ‘owncloud’@’localhost’ IDENTIFIED BY ‘set_database_password‘;

Warning: Be sure to put an actual password where the command states: set_database_password

With the user assigned access to the database, perform the flush-privileges operation to ensure that the running instance of MySQL knows about the recent privilege assignment:

• FLUSH PRIVILEGES;

This concludes the configuration of MySQL, therefore we will quit the session by typing:

• exit

With the ownCloud server installed and the database set up, we are ready to turn our attention to configuring the ownCloud application.

Step 3 – Configuring ownCloud

To access the ownCloud web interface, open a web browser and navigate to the following address:

https://server_domain_or_IP/owncloud

If a self-signed certificate is being used, you will likely be presented with a warning because the certificate is not signed by one of your browser’s trusted authorities. This is expected and normal. We are only interested in the encryption aspect of the certificate, not the third-party validation of our host’s authenticity. Click the appropriate button or link to proceed to the ownCloud setup page.

You should see something like this:

Create an admin account by choosing a username and a password. For security purposes it is not recommended to use something like “admin” for the username.

Before clicking the Finish setup button, click on the Storage & database link:

Leave the Data folder setting as-is and click the MySQL/MariaDB button in the Configure the database section.

Enter the database information that you configured in the previous step. Below is an example, which matches the database credentials that we used in this guide:

Click the Finish setup button to sign into ownCloud. A safe home for all your data splash screen should appear:

Click the x in the top-right corner of the splash screen to access the main interface:

Here, you can create or upload files to your personal cloud.