Increasing the Size of Devices with disk resize

The disk resize command allows you to increase the size of your database devices dynamically, rather than initializing a new device.

For example, if /SAP_ASE/testdev.dat requires an additional 10MB of space, you can run disk resize and allocate this amount of space to the device. The create and alter database commands can use this added space.

Use disk resize to increase the size for both devices on raw partitions and for file systems. The minimum amount of space by which you can increase a device is 1MB or an allocation unit, whichever is greater.

Page Size	Allocation Unit Size	Minimum Incremental Size
2K	0.5MB	1MB
4K	1MB	1MB
8K	2MB	2MB
16K	4MB	4MB

You cannot use disk resize on dump or load devices.

Any properties that are set on the device continue to be set after you increase its size. That is, if a device has dsync set before you increase its size, it has dsync set afterwards. Also, any access rights that were set before you increased the size of the device remain set.

A user with the sa_role can execute the disk resize command, which:

Updates the high value in master....sysdevices, and
Prepares the additional space for database storage.

Use audit trails on disk resize to track the number of times a device is resized. The device being resized is always online and available for users during the resize operation.

Resizing a disk requires that:

You have already initialized the device with disk init.
device_name must refer to a valid logical device name.
You disable mirroring while the resize operation is in progress. You can reestablish mirroring when the resize operation is complete.

In this example, the configuration of the device testdev is:

sp_helpdevice testdev
device_name  physical_name          description
  status  cntrltype  vdevno          vpn_low           vpn_high
-----------  -------------------    -------------
  ------- ---------  -------------   -------------     --------------
testdev      /SAP_ASE/dev/testdev.dat   special, dsync on, directio off, physical disk, 10.00MB   16386    0           1                     0              5119

To increase the size of testdev by 4MB using disk resize, enter:

disk resize 
name = "test_dev", 
size = "4M"

testdev.dat is now 14MB:

sp_helpdevice testdev
device_name  physical_name          description
  status  cntrltype  vdevno          vpn_low           vpn_high
-----------  -------------------    -------------
  ------- ---------  -------------   -------------     --------------
testdev      /SAP_ASE/dev/testdev.dat   special, dsync on, directio off, physical disk, 14.00MB   
  16386           0         1          0                  7167

See the Reference Manual: Commands for disk resize syntax.