Proware SN-3163S3H-QX, User Manual

Page: 127 / 237

SAS / SATA II NAS System
User Manual 127
[Setting]
‹ Port to Bind - A TCP port to bind locally and is used to connect to the remote node.
Default is 7788.
NOTE: User cannot use ports that already have been used.
Available ports are from 7788 to 77xx.
‹ Connection Type: proNAS supports two types of data replication protocols:
Sync - Synchronous. The system will acknowledge the transaction as completed
after the data is written to the disk of destination proNAS. It is recommended to
use this mode. In most cases, this connection type preserves transaction
semantics. Write IO is reported as completed if it has reached the remote disk.
Async (for high latency network) - Asynchronous. The system will acknowledge
the transaction as completed after the data is written to buffer. It provides faster
transmission and is suitable for busy network. Write IO is reported as completed
if it has reached the local TCP send buffer.
‹ Max Sync Rate – This sets the limit of the bandwidth that will be used by the
synchronization process. Default is 30MB/sec. Minimum value is 4MB/sec and
maximum value is 680 MB/sec – for high latency network environment (e.g. bonding
on Gigabit Ethernet).
‹ Send buffer size (K) - It is the size of the TCP socket send buffer. You can specify
smaller or larger values. Larger values are appropriate for reasonable write
throughput with asynchronous protocol over high latency networks. Default is 512K
and maximum is 1024K.
‹ Time out (sec) - It is the value to wait for connection timeout if the remote node is
degraded. If the remote node fails to send the response packet within the specified
timeout time, the remote node will be considered dead and the TCP/IP connection is
abandoned. The default is 6 sec. Minimum is 1 sec and maximum is 60 sec.
‹ When Lost Connection : When the replication connection is lost, the replication
program can either go stand-alone or will try to reconnect.
Reconnect: The replication program will attempt to reconnect. (Default)
Stand-alone: The replication program will not attempt to reconnect and will go
on stand-alone state. All IO request are only passed locally and no replication.
NOTE: Before replication will be successfully created, a 4GB logical
volume will be created on each node. This will serve as the
metadata device for the replicated volume. This volume is not
mounted and will not be seen on the proNAS GUI. Please be sure
to have an extra 4GB space on either side of your NAS nodes.