KZPBA PCI SCSI adapter
Table of Contents
General description
KZPBA is a PCI SCSI adapter based on the QLogic ISP1040 Fast Wide SCSI adapter chip for HP Alpha.
In CHARON Virtual Machine (VM) environment it supports up to 120 disks and tapes.
For systems with more than 16 heavily used units it is recommended to configure several virtual KZPBA PCI SCSI adapters and distribute the heavily loaded units evenly between the adapters.
Loading KZPBA storage adapter
Syntax for loading KZPBA storage adapter:
load KZPBA <name> |
Example:
load KZPBA PKA |
In AlphaStation 400 configuration use the following syntax for KZPBA storage adapter loading:
load KZPBA PKB irq_bus = isa
The adapter instance name ("PKA" in the example above) is used then for parametrization, for example:
set PKA container[602]="C:\My disks\vms_distribution.vdisk" |
The numbers in the square brackets represent SCSI ID and LUN of the devices on the virtual KZPBA SCSI bus.
They have the following format: XXYY, where:
Parameter | Range | Description |
---|---|---|
XX | 0..15 | SCSI ID |
YY | 00..07 | LUN |
By default KZPBA adapter uses first available PCI slot. If instead some particular slot is needed, refer to this section for details of specific placement of PCI peripherals on CHARON Virtual Machine (VM) PCI bus.
By default each loaded KZPBA SCSI PCI adapter has SCSI ID=7. This setting can be changed with "scsi_id" parameter, for example:
set PKA scsi_id=0 |
CHARON-AXP HP Alpha models may have one or two KZPBA adapters preloaded.
Configuration parameters
The KZPBA PCI SCSI adapter emulation has the following configuration parameters:
scsi_id
Parameter | scsi_id |
---|---|
Type | Numeric |
Value | Specifies SCSI ID of KZPBA PCI SCSI Adapter in a range 0..7 By default the "scsi_id" configuration parameter is set to 7. Example:
|
host, port
Parameter | host, port |
---|---|
Type | Text string |
Value | These parameters are used in SCSI cluster configurations.
By default the "host" and "port" configuration options are not specified. Syntax:
where: connection_number = remote_scsi_id * 100 + lun_id Example - 2 members cluster on the same Charon server - Node 1:
Example - 2 members cluster on the same Charon server - Node 2:
|
container
Parameter | container[N] N is "XXYY" number, where XX = SCSI ID (0..15) and YY = LUN (00..07) | ||||||||
---|---|---|---|---|---|---|---|---|---|
Type | Text string | ||||||||
Value | Possible values of the parameter are strings in one of the following forms:
This parameter is initially not set, thus creating NO storage elements on the controller.. |
media_type
Parameter | media_type[N] N is "XXYY" number, where XX = SCSI ID (0..15) and YY = LUN (00..07) |
---|---|
Type | Text string |
Value | Instructs CHARON VM to use the supplied value as the PRODUCT field in the SCSI INQUIRY data returned to a software running on virtual HP Alpha system in response to SCSI INQUIRY command. If not specified, CHARON VM attempts to guess the SCSI INQUIRY data based on virtual SCSI device type and underlying container (which is specified in the corresponding container configuration parameter). Initially is not specified. Example: |
removable
Parameter | removable[N] N is "XXYY" number, where XX = SCSI ID (0..15) and YY - LUN (00..07) |
---|---|
Type | Boolean |
Value | When set to "true", the removable configuration parameter instructs CHARON VM to report the corresponding virtual SCSI device as removable. Note to set this parameter to "true" if this disk storage element is:
By default the removable configuration parameter is set to "false". Example:
Note that virtual SCSI tapes and CD-ROM devices are always reported as removable regardless of the "removable" configuration parameter. |
geometry
Parameter | geometry [N] N is "XXYY" number, where XX = SCSI ID (0..15) and YY - LUN (00..07) |
---|---|
Type | Text String |
Value | This formatted string value specifies the explicit geometry of the disk storage element. This parameter is not applicable to tape storage elements. The string format is <X>”/”<Y>[“/”<Z>][“/”<B>] or <X>”,”<Y>[“,”<Z>][“,”<B>] where:
If this parameter is not set, CHARON VM will configure the geometry based on the most probable disk type. Initially not set. It is possiblle to specify each parameter independently of another one. The following syntax is used for that:
The syntax described above is applicable only to disk storage elements. If the container is a tape image, the following format is used instead: Syntax:
where:
Example:
|
use_io_file_buffering
Parameter | use_io_file_buffering[N] N is "XXYY" number, where XX = SCSI ID (0..15) and YY = LUN (00..07) |
---|---|
Type | Text String |
Value | Instructs CHARON VM to enable host operating system I/O cache on reading/writing operations. The following values are possible:
Note that this caching has a significant effect only in case of mapping to disk and tape containers, not physical 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:
|
io_queue_depth
Parameter | io_queue_depth[N] N is "XXYY" number, where:
|
---|---|
Type | Numeric |
Value | Specifies KZPBA 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:
|
min_n_of_threads
Parameter | min_n_of_threads |
---|---|
Type | Numeric |
Value | Instructs KZPBA I/O to reserve a given number of working threads in a range 1..64, thus improving the performance. All units of KZPBA 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:
|
Empty disk images are created with the "MkDisk" utility. Tape images ("*.vtape") will be created automatically if they don't exist (no utility needed).
CHARON-AXP is able to boot from disk images of any OpenVMS/Alpha and Tru64 version.
The virtual KZPBA storage controller examines the file extension (vdisk
or vtape
) to distinguish between a disk image and a tape image.
Configured physical devices or tape/disk images that do not exist on the host system will, in general, cause OpenVMS/Alpha to report the unit offline. In some cases this will result in a VMS BUG CHECK. In this case, an error message will be written to the log file.
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