VERITAS Volume Manager 3.1 Administrator's Guide

Volume Manager Operations

Common Volume Manager Commands

Chapter 3142

vxunreloc command is run immediately after the replacement.

Restarting the vxunreloc Program After Errors Internally, the

vxunreloc program moves subdisks in three phases.The ﬁrst phase

creates as many subdisks on the speciﬁed destination disk as there are

subdisks to be unrelocated. When the subdisks are made, the vxunreloc

program ﬁlls in the comment ﬁeld in the subdisk record with the string

UNRELOC for identiﬁcation. In the second phase, the data is moved. If all

the subdisk moves are successful, the third phase clears the comment

ﬁeld of the subdisk records.

Making the subdisk is an all-or-none operation. If the vxunreloc

program cannot make all the subdisks successfully, no subdisks are

made and the vxunreloc program exits. The operation of the subdisks

move is not all-or-none. One subdisk move is independent of another, and

as a result, if one subdisk move fails, the vxunreloc utility prints an

error message and then exits. However, all of the subsequent subdisks

remain on the disk where they were hot-relocated and are not moved

back. Subdisks that are returned home retain the UNRELOC string in the

comment ﬁeld of the subdisk records because the cleanup phase does not

execute.

If the system goes down after the new subdisks are made on the

destination, but before they are moved back, the unrelocate utility can

be executed again after the system is brought back up. As described

above, when a new subdisk is created, the vxunreloc command sets the

comment ﬁeld of the subdisk to UNRELOC. Re-execution of the vxunreloc

command checks the offset, the len, and the comment ﬁelds of the

existing subdisks on the destination disk to determine if the subdisks

were left on the disk during a previous execution of the vxunreloc

command.

NOTE Do not manually modify the string UNRELOC in the comment ﬁeld.

If one out of a series of subdisk moves fails, the vxunreloc program

exits. Check the error that caused the subdisk move to fail and

determine if the unrelocation can proceed. When you re-execute the

vxunreloc command to resume the subdisk moves, it uses the subdisks

created at a previous run.