Veritas InfoScale™ 7.3.1 Troubleshooting Guide - Solaris
- Introduction
- Section I. Troubleshooting Veritas File System
- Section II. Troubleshooting Veritas Volume Manager
- Recovering from hardware failure
- Failures on RAID-5 volumes
- Recovery from failure of a DCO volume
- Recovering from instant snapshot failure
- Recovering from failed vxresize operation
- Recovering from boot disk failure
- Hot-relocation and boot disk failure
- Recovery from boot failure
- Repair of root or /usr file systems on mirrored volumes
- Replacement of boot disks
- Recovery by reinstallation
- Managing commands, tasks, and transactions
- Backing up and restoring disk group configurations
- Troubleshooting issues with importing disk groups
- Recovering from CDS errors
- Logging and error messages
- Troubleshooting Veritas Volume Replicator
- Recovery from configuration errors
- Errors during an RLINK attach
- Errors during modification of an RVG
- Recovery on the Primary or Secondary
- Recovering from Primary data volume error
- Primary SRL volume error cleanup and restart
- Primary SRL header error cleanup and recovery
- Secondary data volume error cleanup and recovery
- Troubleshooting issues in cloud deployments
- Recovering from hardware failure
- Section III. Troubleshooting Dynamic Multi-Pathing
- Section IV. Troubleshooting Storage Foundation Cluster File System High Availability
- Troubleshooting Storage Foundation Cluster File System High Availability
- Troubleshooting CFS
- Troubleshooting fenced configurations
- Troubleshooting Cluster Volume Manager in Veritas InfoScale products clusters
- Troubleshooting Storage Foundation Cluster File System High Availability
- Section V. Troubleshooting Cluster Server
- Troubleshooting and recovery for VCS
- VCS message logging
- Gathering VCS information for support analysis
- Troubleshooting the VCS engine
- Troubleshooting Low Latency Transport (LLT)
- Troubleshooting Group Membership Services/Atomic Broadcast (GAB)
- Troubleshooting VCS startup
- Troubleshooting service groups
- Troubleshooting resources
- Troubleshooting I/O fencing
- System panics to prevent potential data corruption
- Fencing startup reports preexisting split-brain
- Troubleshooting CP server
- Troubleshooting server-based fencing on the Veritas InfoScale products cluster nodes
- Issues during online migration of coordination points
- Troubleshooting notification
- Troubleshooting and recovery for global clusters
- Troubleshooting licensing
- Licensing error messages
- VCS message logging
- Troubleshooting and recovery for VCS
- Section VI. Troubleshooting SFDB
System failures
RAID-5 volumes are designed to remain available with a minimum of disk space overhead, if there are disk failures. However, many forms of RAID-5 can have data loss after a system failure. Data loss occurs because a system failure causes the data and parity in the RAID-5 volume to become unsynchronized. Loss of synchronization occurs because the status of writes that were outstanding at the time of the failure cannot be determined.
If a loss of sync occurs while a RAID-5 volume is being accessed, the volume is described as having stale parity. The parity must then be reconstructed by reading all the non-parity columns within each stripe, recalculating the parity, and writing out the parity stripe unit in the stripe. This must be done for every stripe in the volume, so it can take a long time to complete.
Warning:
While the resynchronization of a RAID-5 volume without log plexes is being performed, any failure of a disk within the volume causes its data to be lost.
Besides the vulnerability to failure, the resynchronization process can tax the system resources and slow down system operation.
RAID-5 logs reduce the damage that can be caused by system failures, because they maintain a copy of the data being written at the time of the failure. The process of resynchronization consists of reading that data and parity from the logs and writing it to the appropriate areas of the RAID-5 volume. This greatly reduces the amount of time needed for a resynchronization of data and parity. It also means that the volume never becomes truly stale. The data and parity for all stripes in the volume are known at all times, so the failure of a single disk cannot result in the loss of the data within the volume.