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Configuration parameters

The KGPSA-CA PCI FC adapter emulation has the following configuration parameters:

host_bus_location

Parameterhost_bus_location
TypeText String
Value

(warning) Pass through mode only!

Establish connection between virtual DEC-KGPSA-CA PCI FC adapter and physical EMULEX LightPulse PCI/PCI-X/PCIe FC adapter (pass through mode)

Syntax:

load KGPSA <controller name> host_bus_location="/dev/kgpsa<X>"

Example:

load KGPSA FGA host_bus_location="/dev/kgpsa0"


wwid

Parameter

wwid[N]

N is 0..32766 (no more than 255 units)

TypeText String
Value

Sets WWID for emulated KGPSA adapter unit.

Syntax:

set <controller name> wwid[unit-number]="XXXX-XXXX-XXXX-XXXX-XXXX-XXXX-XXXX-XXXX"

Example:

set FGA wwid[2]="6008-05F3-0005-2950-BF8E-0B86-A0C7-0001"


container

Parameter

container[N]

N is 0..32766 (no more than 255 units)

Type

Text String

Value

Possible values of the parameter are strings in one of the following forms:

  • Physical disk
    • "/dev/sd<L>", where "L" is letter, for example "/dev/sdb"
    • "/dev/disk/by-id/..." - addressing by the disk ID, for example "/dev/disk/by-id/ata-ST1000DM003-9YN162_S1D01QJ4"
    • "/dev/disk/by-label/..." - addressing by the disk label, for example "/dev/disk/by-label/MyStorage"

    • "/dev/disk/by-uuid/..." - addressing by the disk UUID, for example "/dev/disk/by-uuid/0e808a2f-cdd3-4944-a245-f729ffd73882"
      (warning) Please note that existing data on such a disk may be destroyed, depending on how it is used in the emulator.

      Note

      "/dev/sd<L>" addressing is not persistent, so it is strongly recommended to use "/dev/disk/by-id/wwn-*" syntax instead to refer the disk by its WWID - especially in the enviroments utilizing FC and SAN storages.

      These disks must not be formatted by the host OS.

      Example:

      set FGA container[0]="/dev/disk/by-id/ata-ST1000DM003-9YN162_S1D01QJ4"

      It is also possible to use not a whole disk, but previously created partitions on it. In this case the syntax is the following: "/dev/sd<L><N>" where N is the number of partition to be used.

      Example:

      set FGA container[0]="/dev/sdc3"

      .Loop (virtual block) devices

  • Loop (virtual block) devices

    • "/dev/loop<N>"
      Example:

      set FGA container[100]="/dev/loop0"



  • Multipath disk
    • "/dev/dm-<N>"
    • "/dev/mapper/mpath<N>"
    • "/dev/mapper/disk<N>"
      (warning) Be careful not to destroy all the information from the disk dedicated to CHARON-AXP by mistake.  

      These disks must not be formatted by the host OS.

      Example:

      set FGA container[200]="/dev/dm-0"

      .

  • File representing a physical disk of the HP Alpha system (disk image)
    • [<drive>":\"<path-name>”\”]<file-name>[“.vdisk”]
      These files can be created from scratch with "mkdskcmd" utility. Data and OS disk backups are transferred from the original system via tapes or network and restored into these container files. 

      Mapping may also include the full path (recommended), for example: "/my_disks/my_boot_disk.vdisk"

      Example:

      set FGA container[401]="my_dka401.vdisk"

      .

This parameter is initially not set, thus creating NO storage elements on the controller.

media_type

Parameter

media_type[N]

N is 0..32766 (no more than 255 units)

Type

Text String

Value

Instructs CHARON-AXP to use the supplied value as the PRODUCT field in the FC INQUIRY data returned to a software running on virtual HP Alpha system in response to FC INQUIRY command.

If not specified, CHARON-AXP attempts to guess the FC INQUIRY data based on virtual FC device type and underlying container (which is specified in the corresponding container configuration parameter).

Initially is not specified.

Example:

set FGA media_type[0]="HSZ70"


removable

Parameter

removable[N]

N is 0..32766 (no more than 255 units)

TypeBoolean
Value

When set to "true", the removable configuration parameter instructs CHARON-AXP to report the corresponding virtual FC device as removable.

By default the removable configuration parameter is set to "false".

Example:

set FGA removable[400]=true


geometry

Parameter

geometry[N]

N is 0..32766 (no more than 255 units)

Type

Text String

Value

This formatted string value specifies the explicit geometry of the disk storage element.

The string format is <X>”/”<Y>[“/”<Z>] or <X>”,”<Y>[“,”<Z>][“,”<B>] where:

ParameterDescription
XThe number of sectors per track
YThe number of tracks per cylinder
Z

The number of cylinders on the unit.

If omitted, Z is calculated based on X, Y and the total number of sectors on the unit that reflects the size of the disk storage element.

This is an optional parameter.

B

The total size of the disk (in blocks) reported to the guest OS.

If omitted it is calculated automatically.

This is an optional parameter.

If this parameter is not set, CHARON-AXP will configure the geometry based on the most probable disk type.

Initially not set.

Example:

set FGA geometry[201] = "255/255"


Info

It is possiblle to specify each parameter independently of another one. The following syntax is used for that:

set FGA geometry[300]="*,*,*,16777210"



use_io_file_buffering

Parameter

use_io_file_buffering[N]

N is 0..32766 (no more than 255 units)

Type

Boolean

Value

When set to "true", instructs CHARON-AXP to enable host operating system I/O cache on reading/writing operations.

(info) Note that this caching has a significant effect only in case of mapping to disk containers, not physcial drives. 

When enabled, host operating system I/O cache may significantly improve I/O performance of the virtual system. At the same time maintaining I/O cache requires additional host resources (CPU and memory) which may negatively affect overall performance of the virtual system.

Initially is set to "false".

Example:

set FGA use_io_file_buffering[300]=true



io_queue_depth

Parameter

io_queue_depth[N]

N is 0..32766 (no more than 255 units)

TypeNumeric
Value

Specifies KGPSA I/O requests (read or write) for a given unit in a range 2..128

Setting this parameter enables KZPBA instance to run up-to the specifiied numbers of I/O requests (read or write) for unit N in parallel, thus improving the performance.

The default value set by controller is optimal for most of the cases. It may be needed to enlarge this number if guest OS I/O queue for a certain unit contains too much pending entries. In this case the value should be equal to an average size of the queue, collected statistically.

Please do not set this parameter without clear understanding the purpose.

By default parallel execution of I/O requests is disabled.

Example:

set FGA io_queue_depth[603]=4


min_n_of_threads

Parameter

min_n_of_threads

TypeNumeric
Value

Instructs KGPSA I/O to reserve a given number of working threads in a range 1..64, thus improving the performance.

All units of KGPSA instance share the I/O threads.

The default value is equal to number of units plus 2.

For optimization it is possible to set this parameter to sum of the "io_queue_depth" parameters for each unit plus 2. This assumption seems optimal for most of the cases.

Please do not set this parameter without clear understanding the purpose.

Example:

set FGA min_n_of_threads=16



When a disk image connected to an emulated KGPSA-CA controller is dismounted by OpenVMS, it is disconnected from CHARON-AXP and can be manipulated. It can be replaced with a different disk image if it keeps the same name. This capability may be useful when designing back-up and restore procedures. When copying CHARON-AXP disk images while CHARON-AXP is running, please take care to minimize the risk of overloading a heavily loaded CHARON-AXP host system. For example, using a sequential series of simple ftp binary copies is less resource intensive and thus less disruptive than multiple, simultaneous copies.

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