PRIMECLUSTER Global File Services Configuration and Administration Guide 4.2 (Solaris(TM) Operating Environment)

4.7 Extending a GFS Local File System

An existing GFS Local File System can be simply extended by adding new partitions. Data in the files does not have to be saved or restored in this process.

Execute the sfxadd(1M) command to extend the file system. The file system can be extended while the file system is mounted (online extension) or unmounted (offline extension).

However, if you add a partition through online processing, you must specify and execute the -pa -D option beforehand.

Also if the file system is extended while it is unmounted, the status of the file system must be normal. If an attempt is made to extend the file system while the status of the file system is not normal, the sfxadd(1M) command outputs the message, "partition-name is corrupted, run fsck manually." If this occurs, execute the fsck_sfxfs(1M) command to restore the status of the file system. Then, execute the sfxadd(1M) command again.

The table below summarizes whether file system extension can be executed at each setting when the file system is unmounted (offline) or mounted (online).

Extension part	Offline	Online
Data partition addition (-D option)	Executable	Executable

If the file system is probably going to be extended, estimate the maximum size of the extension. Then, specify the data size of the file system when creating the file system (when the mkfs_sfxfs(1M) or sfxnewfs(1M) command is executed). The GFS Local File System records a free data area as an extent. For the free data management area, the area size is calculated automatically so that data in the specified data area can be managed when the file system is created. However, if the file system is extended, this management area can become insufficient. (Because a free data area is recorded as an extent, it can be managed if it is not fragmented. If fragmentation is severe, the free data area cannot be used because of the insufficient management area.)

If the management area seems to be insufficient for an existing file system, the free area may be rearranged for the management area of the file system by defragmenting. For information on defragmentation, see Chapter 8, "Defragmenting GFS Local File System." To check whether the management area is insufficient, specify the -ov option in the df_sfxfs(1M) command to display the total number of leafs and number of free leafs.

If the sfxadd(1M) command has the -pa option specified to pre-register a partition addition, the additional partition is recognized as an existing configuration element for GFS Local File System. Then, the original file system itself is deleted. This occurs if the GFS Local File System is created as another GFS Local File System including the partition that has been pre-registered for addition to delete the addition specification. This also occurs if the sfxadm(1M) command with -D option is executed to delete a pre-registered partition from the file system.

Once a partition has been registered, including ones that have been pre-registered, only the additional partition can be deleted.

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4.7.1 Adding new partition to extend file system