How Do I Configure Data Compression for a Linux Block-Level Migration?

Scenario

By default, data compression is enabled for Linux block-level migrations. The number of compression threads is automatically configured based on the resource usage of source servers. The number of compressions threads depends on the number of idle CPUs but is limited to 3 at most. This may cause high CPU usage. In this case, you can modify the number of compression threads or disable data compression on the SMS console.

Procedure

1. Log in to the SMS console.
2. In the server list, locate the source server to be migrated and click Configure Target in the Migration Stage/Status column.
3. On the Configure Basic Settings tab page, select Configure now next to Advanced Settings to expand advanced settings.
4. At the bottom of the page, select Configure now next to Advanced Options.

   

5. Configure the advanced options listed in the following table.

   Parameter	Setting
   Data Compression	Select Yes if you want to enable data compression during the migration. Then Compression Threads will be available for you to configure. Select No if you do not want to enable data compression during the migration.
   Compression Threads	Configure the maximum number of compression threads that can be launched. If you select auto for this option, the system determines the number automatically. You can also enter an integer from 1 to 3.
   Cache Node Size (MB)	Specify the size of a single data cache node. The value must be an integer ranging from 1 to 8. The default value is 4.

   

   Data compression occupies a large amount of CPU resources. If you enable this function, you need to consider the actual resource usage of the source server to prevent services on it from being affected. For details about the default resource usage, see How Many Resources Will Be Used for a Linux Block-Level Migration?

Modifying Advanced Options

You can only modify the advanced migration options if a task has the target server configured but is not started, is paused, or is waiting to execute an incremental synchronization. After locating the task, in the Operation column, choose More > Manage Migration Settings > Configure Advanced Options. Then you can modify the settings of Data Compression, Compression Threads, and Cache Node Size.