HP ProLiant DL380G5-WSS 3.7.0 HP StorageWorks HP Scalable NAS File Serving Sof - Page 254

system's physical memory. For example, for a 16GB system, this would mean setting the parameter to 800000. HP has seen some cases where a slightly higher value (6 or 7% of physical memory) further improves replication performance. • vm.Vfs_cache_pressure controls the rate at which filesystem inode structures are freed from the system and should be set to a value of 10000 when replicating large sets of files. This will ensure that the system cache does not get overrun with filesystem inode structures when replicating. In the HP Scalable NAS software-only product, the SizingActions script (found in /etc/opt/hpcfs) sets these parameters to values that are appropriate for a system not running replication. You can edit the SizingActions file to change these parameters as appropriate; use your favorite text editor to edit the file and save it back in the same location. (Elsewhere in this guide, HP recommends against editing the SizingActions file. In this instance, editing it is the appropriate solution to setting the parameters.) If, as is the case with some configurations, you do not run the SizingActions script at startup (for example, you are running Oracle or some other major application that has its own tuning recommendations), you will need to set the parameters in the /etc/sysctl.conf file so that they are reset at system startup. ssh configuration The replication feature uses ssh to communicate with the destination cluster. To use ssh, a matching key pair must be in place on the source and destination clusters. HP Scalable NAS includes a default key pair that should be installed on each cluster. (If desired, you can create a custom key pair and then install that key pair on the source and destination clusters. See Create a custom ssh key pair, page 269.) The rplkeys command is used to install the key pair. The command also tunes the sshd_config file on each cluster to support 200 simultaneous ssh connection starts (the default is 10). The command adds a comment before the changed line in the file indicating when the value was changed. The replication processes are run as root, but the private key used is not in the default location (~root/.ssh) on the source cluster. Instead, it is in /_adminfs/ replication/authentication/replication_ssh_key. The public key is published to the destination cluster node in ~/.ssh/authorized_keys with 'replication' in the comment section at the end of the key. 254 Configure and manage replication