How can I move a Virtuoso database from one hardware and/or software platform to another?

Sometimes your preferred Virtuoso-hosting hardware (e.g., Alpha, IA_64, PowerPC?, SPARC, x86, x86_64) or operating system (e.g., AIX, HP-UX, Linux, Mac OS X, Solaris, Windows) changes.

Different OS and processor architectures may use incompatible database file formats -- so your Virtuoso database cannot simply be copied from one machine to the other, but requires some structural changes.

Virtuoso offers some powerful, but still easy to use, features for such migrations. More details on these features are in the main product manual.

General procedure

Simply put, the current Virtuoso instance must be told to produce a "dump" file (basically, a special form of transaction log) from the current database. This file may be created on, subsequently moved to, or made accessible from, the new Virtuoso host. The new Virtuoso instance must then be told to restore the dump file (through a special form of transaction replay).

Adding an extra command argument (+log6) enables the upgrade and migration from Virtuoso 5 to Virtuoso 6 or Virtuoso 7. This argument must be added to both the "dump" and the "restore" commands.

There are two Virtuoso command arguments which will produce a "dump" file. Both of these write to the INI-file (e.g., virtuoso.ini) specified transaction log (e.g., virtuoso.trx), so you may need to edit your INI file before proceeding further.

The first dump-producing command argument, +backup-dump, will only work when your database is in good health.

The second dump-producing command argument, +crash-dump, may be used when your database is in good health, but is intended for use when recovering from many forms of database corruption.

If you're starting with a Virtuoso 5 server, and migrating to a Virtuoso 6 or later server, append +log6 after +backup-dump or +crash-dump. Note: The extra +log6 argument is not needed, and may have unexpected effect, so please leave it off if starting with a Virtuoso 6 server and moving to Virtuoso 6 or later.

In the following examples, we demonstrate moving a Virtuoso database from Solaris running on SPARC, to Solaris running on x86_64. The Virtuoso commands will follow the same form on any platform. The methods and commands used to mount, write to, and/or read from remote filesystems may vary with the operating system and filesharing tools. NFS (used here) should work in most cases.

Sample execution

  1. Stop db;
  2. (Optional) mount remote filesystem;
  3. Edit INI;
  4. Create the dump file with one of these commands -- 

    virtuoso-iodbc-t [+backup-dump] [+log6]
virtuoso-iodbc-t [+crash-dump] [+crash-dump-data-ini arg] [+log6]

  5. (Optional) copy dump file to remote filesystem;
  6. (Optional) mount dump host filesystem from restoration host;
  7. Replay dump file with the command 

    +restore-crash-dump

    Important note: You MUST use the +restore-crash-dump argument, NOT the +restore-backup argument, or the restoration will not succeed. +restore-backup applies only to online backups.

NFS Notes

This is based on Solaris hosts on both ends. There will be some variation across platforms.

On NFS Server (where the files really will be)


svcadm -v enable -r network/nfs/server

/etc/init.d/nfs.server start

share -F nfs -o rw <path_to_shared_directory>

share

In at least one case, the above sequence had to be repeated after a server-side reboot, before the client-side would work.

On NFS Client (where the applications/users are)


mkdir <local_mount_point>

chmod 777 <local_mount_point>

mount -F nfs <server_FQDN>:<path_to_shared_directory> <local_mount_point>

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