JoaoJandre commented on code in PR #664: URL: https://github.com/apache/cloudstack-documentation/pull/664#discussion_r3589445990
########## source/adminguide/kboss_plugin.rst: ########## @@ -0,0 +1,281 @@ +.. Licensed to the Apache Software Foundation (ASF) under one + or more contributor license agreements. See the NOTICE file + distributed with this work for additional information# + regarding copyright ownership. The ASF licenses this file + to you under the Apache License, Version 2.0 (the + "License"); you may not use this file except in compliance + with the License. You may obtain a copy of the License at + http://www.apache.org/licenses/LICENSE-2.0 + Unless required by applicable law or agreed to in writing, + software distributed under the License is distributed on an + "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + KIND, either express or implied. See the License for the + specific language governing permissions and limitations + under the License. + +.. _KBOSS Backup and Recovery Plugin: + +KBOSS Backup and Recovery Plugin +================================ + +About the KBOSS Backup and Recovery Plugin +------------------------------------------ + +The KVM Backup on Secondary Storage Backup and Recovery Plugin provider was designed to provide a complete B&R experience for KVM. It uses already validated methods +to create incremental backups of VMs. Its main characteristics are: + - Full or incremental backups, configured by the user. + - Support for backup compression. + - Support for backup validation. + - Support for "quick restore", inspired by Veeam's Instant Recovery. + - Incremental disk-only VM snapshot compatible (see :ref:`Disk-only-File-based-Storage-Instance-Snapshots-on-KVM`). + - Backups are stored in the secondary storage. + +While by default the backups are stored in any secondary storage available, sharing the same space with templates, ISOs and snapshots, +using the :ref:`Direct resources to a specific secondary storage` feature, it is possible to create backup-exclusive secondary storages. + +Currently, only backup of VMs from the NFS, File-based Shared Mountpoint and Local Storage based Primary Storage are supported. + +Since the KBOSS plugin is fully implemented by ACS, and does not depend on any outside provider, the **importBackupOffering** API is not used. +Instead, use the **createBackupOffering**, which allows users to configure KBOSS features they want to use. These backup offerings are then +assigned and used with KVM instances to perform support B&R actions and operations. + + +Using the KBOSS Backup and Recovery Plugin +------------------------------------------ +To use the KBOSS Backup and Recovery Plugin, the Backup and Recovery framework needs to be enabled first. Then the backup plugin 'kboss' needs to be enabled +on either the global or zone settings. + +================================= ======================== +Configuration Value +================================= ======================== +backup.framework.enabled true +backup.framework.provider.plugin kboss +================================= ======================== + +Once the above two configurations are set, restart the cloudstack-management service. +After, we can create the first backup offering. Navigate to the Service Offerings -> Backup Offerings tab. Click on 'Create Backup Offering' and fill the form. + +=============================== ======================== +Field Value +=============================== ======================== +Name A suitable name to represent the Backup Offering. +Description A suitable description to represent the Backup Offering. +Zone Zone UUID for the backup offering. +Allow User driven backups Whether to allow backups from the ACS API. If this value is false, you will not be able to create backups using KBOSS. **It must be set as true**. +Public Whether the offering is public or dedicated to a domain. +Domain Domain to dedicate the offering, only shown when 'Public' is false. +Compress Whether the backups should be compressed after creation. +Compression library Which compression library to use, only shown when 'Compress' is true. +Validate Whether to validate backups after creation. +Validation steps Which validation steps should be executed. +Allow extract file Whether backups created with this offering should allow file extraction. This feature will be implemented in a future version. +Allow quick restore Whether backups created with this offering should allow quick restore. +Backup chain size The backup chain size of the incremental backups. This value overwrites what is set in `backup.chain.size`. +=============================== ======================== + +.. image:: /_static/images/create-backup-offering.png + :align: center + :alt: NAS Backup repository + +After this has been done, you can go to any Instance view and assign the backup offering to it. Then, there will be buttons available for either ad-hoc +backup or a scheduled backup of the VM. + +Quiesce (Filesystem Freeze and Thaw) +------------------------------------ + +Users can set quiesce to true while creating a backup or a backup schedule. +When a backup is initiated with quiesce enabled, CloudStack uses QEMU guest agent +to freeze the filesystem before starting backup. This operation flushes all dirty +filesystem buffers to disk and quiesces new writes. The filesystem is then thawed +immediately after the backup process starts, keeping the freezing window very short. + +|NASB&R-quiesceInstance.png| + +This enhancement brings the KBOSS backup plugin from crash-consistent backups closer to +application-consistent backups. + +Points to note: + +#. The feature requires Qemu Guest Agent to be installed and running on the guest instance. +#. This method does not capture the memory state of the guest. Any data held in application memory + that hasn’t been flushed to disk prior to the filesystem freeze will not be captured. +#. For fully application-consistent backups, guest applications must implement pre-freeze hooks + to flush their internal state to disk before the filesystem is frozen. + +Backup Chain Management +----------------------- + +The size of the incremental backup chain is determined by the `backup.chain.size` zone-wide configuration; furthermore, it may be overwritten on the +offering level. Once the backup chain reaches the configured size, the next backup will be a full backup and a new chain will start. + +If users wish to finalize the backup chain early, the **finishBackupChain** API may be used. It is also available through the VM instance interface on the GUI. +If the VM is in the `BackupError` state, ACS will try to normalize it. Most times ACS is able to normalize it, however, the VM may be unable to be recovered +automatically for a number of reasons, for example if the storage is unavailable. + +Isolated backups +---------------- + +If you want to create a backup that does not depend on any backup chain, you may inform the `isolated` flag when creating a backup, or a backup schedule. +When set, the created backup will be a full backup, with no dependencies on other backups, and no future backups will depend on it. + +Quick restore +------------- + +If the backup was created using an offering with `allowQuickRestore` set, the user will be able to restore it using the `quickRestore` flag. +When this is done, CloudStack creates new deltas on primary storage that have the backup as their backing files, while the backups are still on the +secondary storage. Then, the VM is automatically started and the volume consolidation process starts. While this is done, the VM is already available to use. + +While this process is ongoing, the VM should not be stopped (from inside the VM), otherwise, it will fail to consolidate the volume. The benefit of using quick restore +is that the VM is up and running in a very short time; however, the time to finish the consolidation process is bigger than normal restore. During +the consolidation process, the VM's disk might have their performance slowed, when the process is done, the performance should go back to normal. + +Compression +----------- + +The backup compression process is executed asynchronously after the backup is created, for VMs using backup offerings that support it. +There are several configurations that affect the backup compression task and process: + +.. list-table:: Compression Configurations + :widths: 20 60 20 + :header-rows: 1 + + * - Configuration + - Description + - Default value + * - `backup.compression.task.enabled` + - Determines whether the task responsible for scheduling compression jobs is active. If not, compression jobs will not run + - true + * - `backup.compression.max.concurrent.operations.per.host` + - Maximum number of concurrent compression jobs. Values lower than 1 disable the limit. + - 5 + * - `backup.compression.max.concurrent.operations` + - Maximum number of compression jobs that can be executed at the same time in the zone. Values lower than 1 disable the limit. + - 10 + * - `backup.compression.max.job.retries` + - Maximum number of attempts for executing compression jobs + - 2 + * - `backup.compression.retry.interval` + - Interval, in minutes, between attempts to run compression jobs + - 60 + * - `backup.compression.timeout` + - Timeout, in seconds, for running compression jobs + - 28800 + * - `backup.compression.minimum.free.storage` + - Minimum required available storage to start the backup compression process. + This setting accepts a real number that is multiplied by the total size of the backup to determine the necessary available space. + By default, the storage must have the same amount of available space as the space occupied by the backup. This is checked by the host + when trying to start the process. + - 1 + * - `backup.compression.coroutines` + - Number of coroutines used for the compression process, each coroutine has its own thread + - 1 + * - `backup.compression.rate.limit` + - Compression rate limit, in MB/s. Values less than 1 disable the limit + - 0 + +To check information about compression jobs, the **listBackupServiceJobs** API may be added. + +Validation +---------- + +The backup validation process is executed asynchronously after the backup is created, for VMs using backup offerings that support it. To perform the validation, a temporary dummy +VM is created using the backup being validated and a few configurable validation steps are executed. After the first successful validation, a Hash of the backup is taken, +a new Hash is taken periodically and compared with the original to make sure the backup is still valid. Furthermore, most backup validation steps are dependant on the guest VM having +Qemu Guest Agent installed and configured to run on start. There are three currently available validation steps: + +.. list-table:: Validation steps + :widths: 20 60 20 + :header-rows: 1 + + * - Step + - Description + - Needs Qemu Gest Agent? + * - `wait_for_boot` + - Waits during a configurable timeout for the validation VM to boot. + - Yes + * - `execute_command` + - Executes a configurable command inside the VM using Qemu Guest Agent, compares the result with a configurable expected result + - Yes + * - `screenshot` + - Takes a screenshot of the VM's window after a configurable time. The screenshot can then be downloaded via `downloadValidationScreenshot` API. + - No + +More validation steps may be added in the future. + +The configurations related to backup validation are detailed below: + +.. list-table:: Validation configurations + :widths: 10 70 10 10 + :header-rows: 1 + + * - Configuration + - Description + - Default value + - Scope + * - `backup.validation.task.enabled` + - Determines whether the task responsible for scheduling validation jobs is active. If it is not active, validation jobs will not run. + - `true` + - Account + * - `backup.validation.interval` + - Interval, in hours, between two validations of the same backup. + - `24` + - Account + * - `backup.validation.max.concurrent.operations` + - Maximum number of validation jobs that can be executed at the same time in the zone. Values lower than 1 disable the limit. + - `10` + - Zone + * - `backup.validation.max.concurrent.operations.per.host` + - Maximum number of validation jobs that can be executed at the same time on each host. Values lower than 1 disable the limit. + - `1` + - Cluster + * - `backup.validation.boot.default.timeout` + - Default timeout, in seconds, for the boot validation step + - `240` + - Account + * - `backup.validation.script.default.timeout` + - Default timeout, in seconds, for the script validation step + - `60` + - Account + * - `backup.validation.screenshot.default.wait` + - Default waiting time, in seconds, before executing the VM screenshot + - `60` + - Account + * - `backup.validation.end.chain.on.fail` + - If true, ends the current backup chain if backup validation fails and the backup belongs to that chain. + - `true` + - Account + * - `enforce.resource.limit.on.backup.validation.vm` + - If true, the creation of validation VMs is bound by the account/domain resource limits. + - `false` + - Account + +To configure the validation steps on a VM level, new VM settings were created. Most of them are available to end-users by default, except the timeouts. The availability of +these settings to User accounts may be configured by the `user.vm.readonly.details` global configuration. It is expected that users use these settings to configure the validation +process, especially the `execute_command` step, which if not configured using the VM settings will not run. Below is a table of the VM settings pertaining to the backup +validation process: + +.. list-table:: Validation VM settings + :widths: 20 80 + :header-rows: 1 + + * - Setting + - Description + * - `backupValidationCommand` + - Command to be executed during the command execution step. The step will not run if this configuration does not have a value + * - `backupValidationCommandArguments` + - Arguments to be passed to the command executed during the command execution step + * - `backupValidationCommandExpectedResult` + - Expected result of the command execution, coded in Base64. If not provided, the process exit code will be checked for value `0` + * - `backupValidationCommandTimeout` + - Timeout for the command executed during the command execution step. Overrides the global configuration + * - `backupValidationScreenshotWait` + - Waiting time before executing the screenshot during the screenshot step. Overrides the global configuration + * - `backupValidationBootTimeout` + - Timeout for the VM boot. Overrides the global configuration + +To check information about validation jobs, the **listBackupServiceJobs** API may be added. Review Comment: ```suggestion To check information about validation jobs, the **listBackupServiceJobs** API may be used. ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
