How to Create Initial State Database Replicas From Scratch (Command Line)

This task is the equivalent of the previous one. It demonstrates the use of the command line utilities to create state database replicas.

After checking the prerequisites ("Prerequisites for Creating State Database Replicas"), and the preliminary information ("Preliminary Information for Creating State Database Replicas"), use the metadb(1M) command to create state database replicas. Refer to the metadb(1M) man page for more information.

When you run the metadb(1M) command for the first time, the system displays a warning message that no state database replicas exist for this host. Ignore this message. It appears only when you create the state database replicas for the first time.

Example -- Creating Initial State Database Replicas on a System With Five Disks

# metadb -a -f c0t1d0s3 c1t1d0s3 c2t1d0s3 c3t1d0s3 c4t1d0s3
# metadb
 
        flags         first blk      block count
     a        u         16              1034            /dev/dsk/c0t1d0s3
     a        u         16              1034            /dev/dsk/c1t1d0s3
     a        u         16              1034            /dev/dsk/c2t1d0s3
     a        u         16              1034            /dev/dsk/c3t1d0s3
     a        u         16              1034            /dev/dsk/c4t1d0s3

The -a and -f options are used together to create the initial state database replicas. Five initial state database replicas, one on each of five slices, are created. By spreading the state database replicas across controllers, you can increase metadevice performance and reliability. The metadb command checks that the replicas are active, as indicated by the -a flag.

Example -- Creating Initial State Database Replicas on a System With Three Disks

# metadb -a -f -c 2 c0t1d0s3 c1t1d0s3 c2t1d0s3
# metadb
 
        flags         first blk      block count
     a        u         16              1034            /dev/dsk/c0t1d0s3
     a        u         1050            1034            /dev/dsk/c0t1d0s3
     a        u         16              1034            /dev/dsk/c1t1d0s3
     a        u         1050            1034            /dev/dsk/c1t1d0s3
     a        u         16              1034            /dev/dsk/c2t1d0s3
     a        u         1050            1034            /dev/dsk/c2t1d0s3

The -a and -f options are used together to create the initial state database replicas. The -c 2 option puts two state database replicas on each specified slice, creating a total of six replicas. By spreading the state database replicas across controllers, you can increase metadevice performance and reliability. The metadb command checks that the replicas are active, as indicated by the -a flag.

Example -- Creating Initial State Database Replicas on a System With Only One Disk

# metadb -a -f -c 3 c0t0d0s3
# metadb
        flags         first blk      block count
     a        u         16              1034            /dev/dsk/c0t0d0s3
     a        u         1050            1034            /dev/dsk/c0t0d0s3
     a        u         2084            1034            /dev/dsk/c0t0d0s3

The system in this example consists of only one disk. (DiskSuite is being installed for its UFS logging feature.) The -a and -f options are used together to create the initial state database replicas. The -c 3 option creates three state database replicas on the same slice on the system's only disk. The metadb command checks that the replicas are active, as indicated by the -a flag.

Use a one-disk configuration for state database replicas as a last resort, as it creates a single point-of-failure.