ExpressCluster X 3.1 for Linux Getting Started Guide - Nec

Designing a system configuration4. If NIC Link Up/Down monitor resource status becomes abnormal when LAN cable link statusis made abnormal status (link down status), NIC Link Up/Down monitor resource cannot beoperated.If the status remains to be normal, NIC Link Up/Down monitor resource cannot be operated.Write function of the mirror disk resource and hybrid disk resourceA mirror disk and a hybrid disk resource write data in the disk of its own server and the diskof the remote server via network. Reading of data is done only from the disk on own server.Writing functions shows poor performance in mirroring when compared to writing to asingle server because of the reason provided above. For a system that requires through-put ashigh as single server, use a shared disk.Not outputting syslog to the mirror disk resource or the hybrid diskresourceDo not set directories or subdirectories which mounted the mirror disk resource or the hybrid diskresource as syslog output destination directories.When the mirror disk connection is disconnected, the I/O to the mirror partition may stop until thedisconnection is detected. The system may become abnormal because of the syslog outputstoppage at this time.When outputting syslog to the mirror disk resource or the hybrid disk resource is necessary,consider the followings. Use bonding as a way of path redundancy of the mirror disk connection. Adjust the user space monitoring timeout value or the mirror related timeout values.Notes when terminating the mirror disk resource or the hybrid diskresourceIn case that processes which access to the directories, subdirectories and files which mountedthe mirror disk resource or the hybrid disk resource exist, terminate the accesses to each diskresource by using ending script or other methods at deactivation of each disk resource likewhen shutdown or failover.Depending on the settings of each disk resource, action at abnormity detection whenunmounting (forcibly terminate processes while each disk resource is being accessed) mayoccur, or recovery action at deactivation failure caused by unmount failure (OS shutdown orother actions) may be executed.In case that a massive amount of accesses to directories, subdirectories or files whichmounted the mirror disk resource or hybrid disk resource are executed, it may take much timebefore the cache of the file systems is written out to the disks when unmounting at diskresource deactivation.At times like this, set the timeout interval of unmount longer enough so that the writing to thedisks will successfully complete.For the details of this setting,see Chapter 4, "Group resource details" in Reference Guide,Settings Tab or Mirror Disk Resource Tuning Properties or Unmount Tab in DetailsTab in "Understanding mirror disk resources" or "Understanding mirror disk resources".Section II Installing ExpressCluster115