Storage Foundation for Oracle® RAC 7.3.1 Administrator's Guide - Linux
- Section I. SF Oracle RAC concepts and administration
- Overview of Storage Foundation for Oracle RAC
- About Storage Foundation for Oracle RAC
- How SF Oracle RAC works (high-level perspective)
- Component products and processes of SF Oracle RAC
- Periodic health evaluation of SF Oracle RAC clusters
- About Virtual Business Services
- About Veritas InfoScale Operations Manager
- About Veritas Services and Operations Readiness Tools (SORT)
- Administering SF Oracle RAC and its components
- Administering SF Oracle RAC
- Setting the environment variables for SF Oracle RAC
- Starting or stopping SF Oracle RAC on each node
- Applying Oracle patches on SF Oracle RAC nodes
- Migrating Pluggable Databases (PDB) between Container Databases (CDB)
- Installing Veritas Volume Manager, Veritas File System, or ODM patches on SF Oracle RAC nodes
- Applying operating system updates on SF Oracle RAC nodes
- Adding storage to an SF Oracle RAC cluster
- Recovering from storage failure
- Backing up and restoring Oracle database using Veritas NetBackup
- Enhancing the performance of SF Oracle RAC clusters
- Administering SmartIO
- Creating snapshots for offhost processing
- Managing database storage efficiently using SmartTier
- Optimizing database storage using Thin Provisioning and SmartMove
- Scheduling periodic health checks for your SF Oracle RAC cluster
- Using environment variables to start and stop VCSMM modules
- Verifying the nodes in an SF Oracle RAC cluster
- Administering VCS
- About managing VCS modules
- Viewing available Veritas device drivers
- Starting and stopping VCS
- Environment variables to start and stop VCS modules
- Adding and removing LLT links
- Configuring aggregated interfaces under LLT
- Displaying the cluster details and LLT version for LLT links
- Configuring destination-based load balancing for LLT
- Enabling and disabling intelligent resource monitoring for agents manually
- Administering the AMF kernel driver
- Administering I/O fencing
- About administering I/O fencing
- About the vxfentsthdw utility
- General guidelines for using the vxfentsthdw utility
- About the vxfentsthdw command options
- Testing the coordinator disk group using the -c option of vxfentsthdw
- Performing non-destructive testing on the disks using the -r option
- Testing the shared disks using the vxfentsthdw -m option
- Testing the shared disks listed in a file using the vxfentsthdw -f option
- Testing all the disks in a disk group using the vxfentsthdw -g option
- Testing a disk with existing keys
- About the vxfenadm utility
- About the vxfenclearpre utility
- About the vxfenswap utility
- Enabling or disabling the preferred fencing policy
- About I/O fencing log files
- Migrating from disk-based fencing to server-based fencing using the installer
- Migrating from server-based fencing to disk-based fencing using the installer
- Administering the CP server
- Administering CFS
- Administering CVM
- Listing all the CVM shared disks
- Establishing CVM cluster membership manually
- Changing the CVM master manually
- Importing a shared disk group manually
- Deporting a shared disk group manually
- Starting shared volumes manually
- Verifying if CVM is running in an SF Oracle RAC cluster
- Verifying CVM membership state
- Verifying the state of CVM shared disk groups
- Verifying the activation mode
- Administering Flexible Storage Sharing
- About Flexible Storage Sharing disk support
- About the volume layout for Flexible Storage Sharing disk groups
- Setting the host prefix
- Exporting a disk for Flexible Storage Sharing
- Setting the Flexible Storage Sharing attribute on a disk group
- Using the host disk class and allocating storage
- Administering mirrored volumes using vxassist
- Displaying exported disks and network shared disk groups
- Tuning LLT for memory and performance in FSS environments
- Backing up and restoring disk group configuration data
- Administering SF Oracle RAC global clusters
- Administering SF Oracle RAC
- Overview of Storage Foundation for Oracle RAC
- Section II. Performance and troubleshooting
- Troubleshooting SF Oracle RAC
- About troubleshooting SF Oracle RAC
- Restarting the installer after a failed network connection
- Installer cannot create UUID for the cluster
- Troubleshooting SF Oracle RAC pre-installation check failures
- Troubleshooting LLT health check warning messages
- Troubleshooting I/O fencing
- SCSI reservation errors during bootup
- The vxfentsthdw utility fails when SCSI TEST UNIT READY command fails
- Node is unable to join cluster while another node is being ejected
- System panics to prevent potential data corruption
- Cluster ID on the I/O fencing key of coordinator disk does not match the local cluster's ID
- Fencing startup reports preexisting split-brain
- Registered keys are lost on the coordinator disks
- Replacing defective disks when the cluster is offline
- Troubleshooting I/O fencing health check warning messages
- Troubleshooting CP server
- Troubleshooting server-based fencing on the SF Oracle RAC cluster nodes
- Issues during online migration of coordination points
- Troubleshooting Cluster Volume Manager in SF Oracle RAC clusters
- Restoring communication between host and disks after cable disconnection
- Shared disk group cannot be imported in SF Oracle RAC cluster
- Error importing shared disk groups in SF Oracle RAC cluster
- Unable to start CVM in SF Oracle RAC cluster
- CVM group is not online after adding a node to the SF Oracle RAC cluster
- CVMVolDg not online even though CVMCluster is online in SF Oracle RAC cluster
- Shared disks not visible in SF Oracle RAC cluster
- Troubleshooting CFS
- Troubleshooting interconnects
- Troubleshooting Oracle
- Error when starting an Oracle instance in SF Oracle RAC
- Clearing Oracle group faults
- Oracle log files show shutdown called even when not shutdown manually
- DBCA fails while creating an Oracle RAC database
- Oracle's clusterware processes fail to start
- Oracle Clusterware fails after restart
- Troubleshooting the Virtual IP (VIP) configuration in an SF Oracle RAC cluster
- Troubleshooting Oracle Clusterware health check warning messages in SF Oracle RAC clusters
- Troubleshooting ODM in SF Oracle RAC clusters
- Troubleshooting Flex ASM in SF Oracle RAC clusters
- Prevention and recovery strategies
- Tunable parameters
- Troubleshooting SF Oracle RAC
- Section III. Reference
About LLT flow control tunable parameters
Table: LLT flow control tunable parameters lists the LLT flow control tunable parameters. The flow control values are set in number of packets. The command lltconfig -F query can be used to display current flow control settings.
Table: LLT flow control tunable parameters
LLT parameter | Description | Default | When to change | Dependency with other LLT tunable parameters |
|---|---|---|---|---|
highwater | When the number of packets in transmit queue for a node reaches highwater, LLT is flow controlled. | 200 | If a client generates data in bursty manner, increase this value to match the incoming data rate. Note that increasing the value means more memory consumption so set an appropriate value to avoid wasting memory unnecessarily. Lowering the value can result in unnecessary flow controlling the client. | This flow control value should always be higher than the lowwater flow control value. |
lowwater | When LLT has flow controlled the client, it will not start accepting packets again till the number of packets in the port transmit queue for a node drops to lowwater. | 100 | Veritas does not recommend to change this tunable. | This flow control value should be lower than the highwater flow control value. The value should not be close the highwater flow control value. |
rporthighwater | When the number of packets in the receive queue for a port reaches highwater, LLT is flow controlled. | 200 | If a client generates data in bursty manner, increase this value to match the incoming data rate. Note that increasing the value means more memory consumption so set an appropriate value to avoid wasting memory unnecessarily. Lowering the value can result in unnecessary flow controlling the client on peer node. | This flow control value should always be higher than the rportlowwater flow control value. |
rportlowwater | When LLT has flow controlled the client on peer node, it will not start accepting packets for that client again till the number of packets in the port receive queue for the port drops to rportlowwater. | 100 | Veritas does not recommend to change this tunable. | This flow control value should be lower than the rpothighwater flow control value. The value should not be close the rporthighwater flow control value. |
window | This is the maximum number of un-ACKed packets LLT will put in flight. | 50 | For performance reason, the adaptive window feature is enabled, by default for port 5 (cfs) and port 24(cvm). You can manually enable adaptive window for other ports by changing the value of the LLT_AW_PORT_LIST parameter in the /etc/sysconfig/llt file.
Change the value as per the private networks speed. Lowering the value irrespective of network speed may result in unnecessary retransmission of out of window sequence packets. | This flow control value should not be higher than the difference between the highwater flow control value and the lowwater flow control value. The value of this parameter (window) should be aligned with the value of the bandwidth delay product. |
linkburst | It represents the number of back-to-back packets that LLT sends on a link before the next link is chosen. | 32 | For performance reasons, its value should be either 0 or at least 32. | This flow control value should not be higher than the difference between the highwater flow control value and the lowwater flow control value. |
ackval | LLT sends acknowledgement of a packet by piggybacking an ACK packet on the next outbound data packet to the sender node. If there are no data packets on which to piggyback the ACK packet, LLT waits for ackval number of packets before sending an explicit ACK to the sender. | 10 | Do not change this value for performance reasons. Increasing the value can result in unnecessary retransmissions. | Not applicable |
sws | To avoid Silly Window Syndrome, LLT transmits more packets only when the count of un-acked packet goes to below of this tunable value. | 40 | For performance reason, its value should be changed whenever the value of the window tunable is changed as per the formula given below: sws = window *4/5. | Its value should be lower than that of window. Its value should be close to the value of window tunable. |
largepktlen | When LLT has packets to delivers to multiple ports, LLT delivers one large packet or up to five small packets to a port at a time. This parameter specifies the size of the large packet. | 1024 | Veritas does not recommend to change this tunable. | Not applicable |