Setting Disk I/O Limits for Container Backups and Migrations

The operations of backing up, restoring, and migrating Containers can generate high disk I/O load on the Hardware Node, thus slowing down the performance of other Containers or of the Hardware Node itself. You can avoid such situations by setting disk I/O limits for these operations.

To set a disk I/O limit, do the following:

1. Open the Virtuozzo global configuration file for editing, for example:

   # vi /etc/vz/vz.conf

2. Locate the following section in the file:

   # VZ Tools IO limit

   # To enable - uncomment next line, check the value - there should not be CT with the same ID

   # VZ_TOOLS_BCID=2

   # Uncomment next line to specify required disk IO bandwidth in Bps (10485760 - 10MBps)

   # VZ_TOOLS_IOLIMIT=10485760

3. Edit this section as follows:
   1. Uncomment the VZ_TOOLS_BCID parameter to enable disk I/O limits for backup, restore, and migration operations. When defining the parameter, make sure that no Container with the specified ID exists on the Hardware Node.
   2. Uncomment the VZ_TOOLS_IOLIMIT parameter, and set the disk I/O limit for backup, restore, and migration operations. The value is set in bytes per second.
4. Save the file.

When setting disk I/O limits, pay attention to the following:

• VZ_TOOLS_BCID and VZ_TOOLS_IOLIMIT are global parameters—that is, once these parameters are set, they have effect on all Containers on the Hardware Node.
• The VZ_TOOLS_BCID and VZ_TOOLS_IOLIMIT parameters control the disk I/O load only for backup, restore, and migration operations.