BCV or Split-Mirror on ASM Diskgroup
Hello,
We know that BCV (EMC) or Split-Mirror (different storage vendors uses different terms) has been in use with ASM storages for few years. What I dont understand is how do they ensure the ASM diskgroup is mirrored without any inconsistency.
We know that the database can be placed in backup mode hence any fractured IO is taken care during the recovery and Oracle database does a direct IO onto ASM disks (means it skips the ASM instance). However there can be operations on the ASM instance such as some metadata change (say, a rebalance is going on, or someone tried to drop the disk or a new disk is added, or a PST update is taking place, or a new AU allocation is going on for a file resize) which are actually happening in memory and not yet flushed to
We know that BCV (EMC) or Split-Mirror (different storage vendors uses different terms) has been in use with ASM storages for few years. What I dont understand is how do they ensure the ASM diskgroup is mirrored without any inconsistency.
We know that the database can be placed in backup mode hence any fractured IO is taken care during the recovery and Oracle database does a direct IO onto ASM disks (means it skips the ASM instance). However there can be operations on the ASM instance such as some metadata change (say, a rebalance is going on, or someone tried to drop the disk or a new disk is added, or a PST update is taking place, or a new AU allocation is going on for a file resize) which are actually happening in memory and not yet flushed to
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