Veritas NetBackup™ Appliance Fibre Channel Guide

Last Published:
Product(s): Appliances (4.0)
Platform: NetBackup Appliance OS
  1. About NetBackup Fibre Transport and SAN Client
    1.  
      About NetBackup Fibre Transport
    2. About NetBackup SAN Client and Fibre Transport
      1.  
        About the SAN Client license key
  2. About optimized duplication and Auto Image Replication over FC
    1.  
      About Fibre Transport for optimized duplication and Auto Image Replication between appliances
  3. About backup to tape support
    1.  
      About backup to tape support for NetBackup appliances
  4. VMware support
    1. About NetBackup appliance as a VMware backup host
      1.  
        NetBackup appliance as backup host: component overview
      2.  
        Notes on NetBackup appliance as a VMware backup host
    2.  
      About appliance dynamic multi-pathing for VMware backups with SAN transport
  5. Supported Fibre Channel features on NetBackup appliances
    1.  
      About supported Fibre Channel features on NetBackup appliances
    2.  
      Fibre Channel feature support with appliance HBA configurations
    3.  
      Supported data transfer methods for NetBackup appliances
    4.  
      About Fibre Transport paths for NetBackup appliances
  6. NetBackup Appliance rear panel configurations
    1.  
      About the NetBackup 5230 rear panel configurations
    2.  
      NetBackup 5240 Appliance I/O configuration options
    3.  
      NetBackup 5240 Appliance total I/O on-board and PCIe ports
    4.  
      NetBackup 5250 Appliance rear panel I/O configuration options
    5.  
      NetBackup 5330 Appliance compute node PCIe slot I/O configuration options
    6.  
      Available NetBackup 5340 Appliance PCIe-based I/O configurations
    7.  
      Available NetBackup 5350 Appliance PCIe-based I/O configurations
  7. About the HBA port mode configuration
    1.  
      Supported Fibre Channel port configurations for the NetBackup 5230 appliances
    2.  
      Supported Fibre Channel port configuration for the NetBackup 5240 appliances
    3.  
      Supported Fibre Channel configurations for the NetBackup 5250 appliance
    4.  
      Supported Fibre Channel port configurations for the NetBackup 53xx appliances
    5.  
      About the factory default port mode configuration
    6.  
      Default port mode configuration for FTMS, optimized duplication, and Auto Image Replication
  8. Zoning the FC SAN
    1.  
      How to determine appliance HBA WWPNs
    2.  
      About zoning the SAN for NetBackup appliances
    3.  
      About HBA link status on the NetBackup Appliance Shell Menu
  9. About the Fibre Transport page on the NetBackup Appliance Web Console
    1. Settings > Network > Fibre Transport
      1.  
        About the HBA port mode configuration table
  10. Configuring Fibre Transport on the appliance
    1. How to configure Fibre Transport media server for SAN Client
      1.  
        Configuring Fibre Transport media server settings
      2.  
        Configuring Fibre Transport settings
      3.  
        About Fibre Transport media server verification
    2.  
      Guidelines for changing NetBackup appliance FT target ports to receive data streams from multiple SAN Client FC initiator ports
    3. How to configure Fibre Transport for optimized duplication and Auto Image Replication over FC
      1. Configuring Fibre Transport to other NetBackup appliances
        1.  
          About the Fibre Transport chunk size
      2.  
        Configuring Fibre Transport on a target appliance for optimized duplication and replication
      3.  
        About Fibre Transport Deduplication target mode port verification
      4.  
        About Fibre Transport target mode verification (model 5350 only)
      5.  
        How to configure two NetBackup 52xx or 53xx appliances in different domains for MSDP replication
  11.  
    Index

About the Fibre Transport chunk size

The chunk size specifies the amount of data that is buffered before transmission over Fibre Transport (FT). It is an advanced setting on the sender side for optimized duplication and replication to other NetBackup appliances over FT.

By default, the chunk size is not set or used. The chunk size setting is not required for optimized duplication and replication over FT. It is highly dependent on user deployment and network status. If you find it necessary to improve backup performance, you can adjust the chunk size as needed to determine a proper value for your environment and the current network status.

Typically, the sender on the initiating appliance receives a block of data and starts the transmission regardless of its size. After this data block is transmitted, the sender waits for a confirmation from the receiver (or target appliance) before it transmits the next block. The transmission continues if the appliance receives confirmations without interruption. If the network latency is high, confirmation time also increases.

By setting the chunk size, you determine that data blocks must be delivered by using chunks of the specified size. In a single transmission session, if the sender receives a block of data that is greater than the specified chunk size, it fragments the data into chunks for transmission. The remaining data from the fragmentation is allocated to the next chunk. If a data block is smaller than the specified chunk size, the sender adds it into the buffer to link it together with data from the preceding or the following block. Data block linking continues until the buffered data has reached the chunk size, and then the appliance transmits the chunk. After transmitting, the sender waits for a confirmation from the receiver before it sends out the next chunk. If the session closes, the remaining data is transmitted.

A data block over FT is typically 128 KB or smaller. Setting the chunk size to a value equal to or greater than 128 KB allows the appliance to link together small data blocks into big chunks. Therefore, fewer confirmations are needed. The result may improve the transmission efficiency when the network latency is high. The data block linking also reduces the overhead that is generated with the data.

Network latency can be high in the following scenarios, and you can consider using the chunk size to see if anything improves.

  • Data transmitted over a long distance and an IP network that is used for the transmission along with FC.

  • Data transmitted over a long distance through an FC-only connection.

    Note:

    If you observe a big downgrade on backup performance over a short-distance FC-only connection, try adjusting the chunk size and see if there is any improvement.

The default value for chunk size is "0", which means the chunk size is not set or used. If you set the chunk size to a value equal or greater than "1", you specify the size of each data chunk that is sent to the FC network. To enable and manage the chunk size setting, use the Main > Support > FibreTransport > ChunkSize command from the NetBackup Appliance Shell Menu. The available chunk size range is 1-2048 KB. The recommended values are 128 KB, 256 KB, 512 KB, 1024 KB, or 2048 KB. You may also need to test with other values to determine a proper value for your environment.

The chunk size may not work for the following reasons:

  • A limited bandwidth

  • Network congestion

  • Not using a dedicated data network