Volume management

To define a set of disks for Linux on System z using the EVMS command line interface follow the steps described below. They create a striped volume with stripe size 32K on the two disks /dev/dasdl1 and /dev/dasdm1. We assume that the used disks have been formatted.

1. Start command line interface
   

   pserver16:~ # evms
   EVMS Command Line Interpreter Version 2.3.3
   EVMS:

   This shows the command line interface where all EVMS commands are placed. Commands are separated by a colon, this permits more than one command at a time. More information about the commands is available with the keyword "help" followed by the colon and the specific command.
   
   For example:

   EVMS: help : create
   

   
   
2. Create "segments" on all disks, define the segment size, in this example the complete disk
   

   EVMS: create : Segment, dasdl_freespace1, size=2320MB : create : Segment, dasdm_freespace1, size=2320MB
The create command created segment: dasdl1
The create command created segment: dasdm1
   

   dasdl_freespace1 and dasdm_freespace1 represent the available free disk portions.
   
   

3. Create "container" from both disks, the name and the pe_size have to be specified
   

   EVMS: create : Container, LvmRegMgr={name="test_container",pe_size=16MB},dasdl1,dasdm1
The create command created container: lvm/test_container
   

   The pe_size is the abbreviation for physical extent size. Physical volumes are divided into units called physical extents.

   
   
4. Create "region" from the container created before, the name and size have to be specified
   

   EVMS: create:region, LvmRegMgr={name="test_region", extents=286, stripes=2, stripe_size=32},"lvm/test_container/Freespace"
The create command created region: lvm/test_container/test_region
   

   The region will be created from the freespace in the used container. The name and the size, either in MB or number of extents, must be set.

   
   
5. Create an "EVMS volume"
   

   EVMS: create: Volume, "lvm/test_container/test_region", Name="test_evms"
   

   The created logical volume can contain a filesystem and can be mounted.

   
   
6. Create a file system on the EVMS volume via EVMS (Also possible via LINUX)
   

   EVMS: mkfs: Ext2/3={vollabel=ext2_3}, /dev/evms/test_evms
   

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