7c0f55fb80
Currently, there are some description of remove older backup with using '--remove-older-then' which is not exist, should use '--remove-older-than' instead. Change-Id: I172e60151549d4478f951c439e5cf248bee038ca
113 lines
4.8 KiB
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113 lines
4.8 KiB
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===
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FAQ
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===
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1) **What is freezer?**
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Is a tool to automate data backup and restore
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process using OpenStack Swift and/or other media storage.
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2) **Does freezer support incremental backup?**
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Yes. Incremental backup are done using GNU tar incremental features.
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3) **Does freezer check the file contents to establish if a file was modified?**
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Freezer check for changes at mtime and ctime in
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every file inode to evaluate if a file changed or not.
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4) **Why GNU tar rather than rsync?**
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Both approaches are good. Rsync check
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the file content, while tar check the file inode. In our
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environment, we need to backup directories with size > 400GB and
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hundreds of thousands of files. Rsync approach is effective but slow.
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Tar is fast as it needs to check only the file inodes, rather than
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the full file content. Rsync backup type will be added pretty soon.
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5) *Does freezer support encrypted backup?*
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Yes. Freezer encrypt data using OpenSSL (AES-256-CFB).
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6) **Does freezer execute point-in-time backup?**
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Yes. For point in time backup LVM snapshot feature used.
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7) **Can I use freezer on OSX or other OS where GNU Tar is not installed
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by default?**
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Yes. For OSX and \*BSD, just install gtar and freezer
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automatically will use gtar to execute backup. OS other then Linux,
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OSX and \*BSD are currently not supported.
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8) **What Application backup does freezer support currently?**
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MongoDB, MySQL to have a higher level of data consistency, while
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any application is supported for crash consistent data integrity.
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9) **How does the MongoDB backup happens?**
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Freezer required journal enabled in Mongo and lvm volume to execute backup.
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It checks if the Mongo instance is the master and create lvm snapshot to have
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consistent data.
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10) **Does freezer manage sparse files efficiently?**
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Yes. Zeroed/null data is not backed up. So less space and bandwidth will be used.
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11) **Does freezer remove automatically backup after some time?**
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Yes. From command line the option --remove-older-than (days) can be used to
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remove objects older then (days).
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12) **Does freezer support MySQL Backup?**
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Yes.
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13) **What storage media are currently supported?**
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Current support media storage are:
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a. Swift
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b. Store files on a remote host file system using ssh
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c. Directory in the local host (i.e. NFS/CIFS mounted volumes)
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14) **Does freezer has any Web UI or API?**
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Yes. Freezer has REST API and a Web UI integrated with Horizon.
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15) **Does Freezer detect removed files between incremental executions?**
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Yes.
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16) **Will Freezer be included as official project in OpenStack?**
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We hope so, as soon as we can.
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17) **Does freezer support Windows?**
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Yes. The freezer agent and scheduler can be executed on Windows.
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18) **What is being used on Windows to execute file system snapshots?**
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Currently VSS are used to support point in time snapshots.
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19) **What applications are supported in Windows for consistent backups?**
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SQL Server (--mode sqlserver).
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20) **Are there examples of OpenStack projects that use Freezer that I can look at?**
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Not currently.
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21) **My service has it's own task scheduler. What is the recommended way to schedule Freezer runs?**
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If you want to use the freezer-api and freezer-web-ui in horizon, you need to use the
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freezer-scheduler.
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If you do not need the api and web ui, you can just execute the freezer-agent from crontab or
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any other scheduler.
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22) **What are the benefits of using the API and Web UI?**
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- You can start backup and restore jobs on any node from the Web UI
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- Backup jobs can be synchronized across multiple nodes
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- The UI provides metrics and other info
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23) **How can I run user-defined scripts before and after a backup run?**
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A simple solution is to implement your own script locally and execute
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freezer-agent from it.
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We recommend instead creating "exec"-type jobs in the UI and set up job
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dependencies.
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24) **What are the options for backing up MySQL/Percona?**
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a. Make use of filesystem snapshots (LVM) using the "--mode mysql" option. It's supported
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natively by Freezer and suitable for large databases.
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This instructs freezer to execute the following steps:
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- flush tables and lock the DB
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- take an LVM snapshot
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- release the DB (so it's usable again very quiclky)
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- backup the consistent DB image from the snapshot
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- release the snapshot
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b. Manual process - It does not require LVM and provides incremental backup.
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- manually flush tables and lock the DB: "flush tables with read lock"
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- backup the DB folder, usually /var/lib/mysql (--mode fs --path-to-backup /var/lib/mysql --max-level 14)
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- manually unlock the DB
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Using mysqldump is not recommended for speed and reliability reasons.
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