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One can re-create a clean SysOrb database using the sysorb-createdb tool. This is required if one wishes to change the database block sizes, or if one wishes to run the database on raw disk devices (or partitions) rather than on a file system (on operating systems where this functionality is available).
The database creation tool will create two or three files, depending on chosen options. The files are:
The meta database.
External journal for main.odb.
The time series database
The tool accepts a number of command line options, described blow:
Print a short help message summarizing usage.
Start the tool in "interactive" mode - this will allow for a more fine grained control over the created database. It is not usually necessary to tweak these settings, and setting them wrong can result in a non-functional database. Use this option with care.
Specify a path in where the database files will be created. The default is to create the files in the current working directory.
Create a completely empty database. This option is not useful in end-user scenarios, as the database will not include the default administrative user, and thus it will not be possible to log into a server started with the empty database.
Force - no questions will be asked by the tool.
A number of advanced settings can be specified in the "interactive" mode of the createdb tool. When using the tool in the standard non-interactive mode, good defaults are chosen. It should not usually be necessary for an administrator to specify these options manually, but there are certain situations where such flexibility is useful.
Most notably, when creating a database on "raw" devices (partitions or volumes, rather than in files on a file system), it is necessary to use the interactive mode in order to specify the individual device locations (as the database needs two or three locations, and if volumes or partitions are used, two or three distinct locations must be specified).
In interactive mode, the user will be prompted for each of the advanced settings in turn:
Journal type: The meta database can use either an internal or an external journal. An external journal allows the administrator to place the journal on a smaller but faster storage device.
Journal size: A too small journal will, sooner or later, cause the SysOrb Server to perform an emergency shutdown. It is absolutely vital, that the journal is not chosen too small. The default journal size is 8 Megabytes, which is sufficient. If the journal can be placed on a very fast storage device, it may be beneficial to raise the journal size somewhat. It is not possible to give hard numbers for this though - a busy metadatabase with the journal on a fast storage device, may see speed improvements from a 16 Megabyte journal. It is generally recommended to just go with the default size of 8 Megabytes though.
Number of chains: The time series database relies on "phase chains" rather than a journal to guarantee consistency over unexpected system shutdowns. A number of chains is allocated - the database needs at least one chain as the "consistent" chain, and one as the "active" chain. Thus, the number of chains can not be set lower than two. Setting the number of chains higher does in theory not improve reliability - it does however give the operating system and hardware some amount of "slack" - the default is three chains.
Block size: A uniform block size is used in both the time series database and the meta database. Meta data objects cannot span blocks in the database, therefore the block size must be large enough for the largest possible object. It is not recommended to set the block size lower than 4 kilobytes, although a minimum of 1 kilobyte is possible using the createdb tool. Both databases use 32-bit block indexing, and are therefore limited in size to approximately four billion blocks. A block size of 8 kilobytes thus results in a maximum database size (for each of the metadata and time series databases) of 32 terabytes. Increasing the block size further will raise this limit. The default block size is 8 kilobytes.
Estimated number of checks: As a convenience, the createdb tool can - upon database creation - allocate space in the time series database for some given number of checks. This is only an initial allocation, and the database will be grown later as needed. The default of 1000 checks will result in a database of approximately one gigabyte in size. For small installations, use a smaller number. Again, the database will be grown as needed, anyone can put "10" here - which will make the creatdb run significantly faster.
The following will create a standard database with the default "admin" (password: "admtest") login in the directory /mnt/database/:
sysorb-createdb -d /mnt/database -f
The following will create a completely empty database:
sysorb-createdb -d /mnt/database -f -c