Overview and High Level Goals
Many pieces of the OpenVault architecture rely on different processes
all using the same terminology to describe what services they offer
and/or things that they describe. That terminology takes the form of
uninterpreted text strings that we call tokens.
This document is a collection of all the currently defined tokens in
all the OpenVault languages and what they mean. Note that since new
tokens can be defined and added by others, this list will almost never
be all-inclusive, but it will also never contain errors. Extensions are
allowed, but not changes to the existing tokens.
Decisions, Assumptions, and Limitations
Please see the documents that define the various subsystems for more
information on the uses and rationale behind these tokens, this is just
a listing of them with a basic meaning.
Open Issues
There are a few questions remaining:
-
Do we have all the basic tokens defined for all the currently existing
drive technologies?
-
What about optical technologies? Are they significantly different?
CAPI Mount Modes
The CAPI interface assumes that there is a standard set of default
drive capabilities and that the application must specify the changes
from that standard that it desires for any given mount command. Here
are the tokens that describe the currently defined delta from that
standard drive.
| Token |
Description |
| read |
the mount point will allow reading of the media |
| write |
the mount point will allow writing of the media |
| rewind |
rewind the media on close of the mount point |
| compression |
attempt compression of the data stream |
| fixed_block |
blocks on the media will be a fixed size |
| status |
a status-only mount point will *ALSO* be created (in a
directory created for this session) |
| audio |
the mount point will allow the app to control the drive's
playing of audio information off the media |
|
Slot Type Names
A Slot Type Name is our name for the external shape of a
cartridge. Slot Type Names are used by LCPs (for obvious reasons), by
DCPs (what shapes of cartridges it can accept and what capabilities it
can offer with cartridges of that shape), and by client applications.
These are the tokens used for the currently existing cartridge shapes.
| Token |
Description or Usage |
| 8mm |
any generic 8mm shell |
| 3480 |
eg: IBM 3480/3490/3495, STK 4480/4490, etc. |
| DLT |
eg: Compact III (ie: DLT2000), Compact IV (ie: DLT7000) |
| DAT |
eg: DDS2 |
| D2-S |
"small" DST cartridges (25GB capacity) |
| D2-M |
"medium" DST cartridges (75GB capacity) |
| D2-L |
"large" DST cartridges (165GB capacity) |
| DFT |
eg: 20GB cartridges from Sony |
| VHS |
eg: Metrum |
| QIC |
|
| CDROM |
eg: CDROM, DVDROM |
|
Bit Formats
The format of the bits that are recorded on the media is independent of
the external shape of the cartridge. One of the better known cases is
that of the 3490 cartridge. It is possible to record bits onto a piece
of 3490 media in the format that the 3490 drive uses, but it is also
possible to record bits on that media in the format that the 3480 drive
uses.
Here are the tokens for the currently defined bit formats, what form
factors it will be found in, and a description of how that format is
generated or by whom.
| Token |
Form Factor |
Description |
| 8200 |
8mm |
Exabyte 8200 native |
| 8200c |
8mm |
Exabyte 8200 native |
| 8500 |
8mm |
Exabyte 8500 native |
| 8500c |
8mm |
Exabyte 8500 compressed |
| mammoth |
8mm |
Exabyte mammoth native |
| mammothc |
8mm |
Exabyte mammoth compressed |
| 3480 |
3480 |
3480 native |
| 3490 |
3480 |
3490 native |
| 3490E |
3480 |
3490E native |
| 3495 |
3480 |
IBM Magstar native |
| 4480 |
3480 |
STK Timberline native |
| 4490 |
3480 |
STK Redwood native |
| DLT2000 |
DLT |
DLT2000 native |
| DLT2000c |
DLT |
DLT2000 compressed |
| DLT4000 |
DLT |
DLT4000 native |
| DLT4000c |
DLT |
DLT4000 compressed |
| DLT7000 |
DLT |
DLT7000 native |
| DLT7000c |
DLT |
DLT7000 compressed |
| DDS1 |
DAT |
|
| DDS2 |
DAT |
|
| DDS3 |
DAT |
|
| D2 |
D2-[SML] |
Ampex DST-310 |
| DFT |
DFT |
Sony GY-10 |
| QIC80 |
QIC |
|
| QIC100 |
QIC |
|
| QIC150 |
QIC |
|
| QIC525 |
QIC |
|
| QIC1024 |
QIC |
|
| ISO9660 |
CDROM |
|
|
Cartridge Type Names
In addition to the external space of the cartridge and the format of
the bits that are recorded on the media in that cartridge, we must also
take into account the ability of that media to accept the various bit
formats that could possibly be applied to it.
For example, in the Exabyte 8mm line a 12m long tape can be read and
written by an 8200 drive and cannot be accessed by an 8500 drive
(something about the tape tensioning being different). Yet, a 160m long
tape with the same external shape can be used by an 8500 drive but not
by an 8200 drive.
Here are the currently defined tokens for each type of cartridge and
the generally accepted product name for that type of cartridge.
| Token |
Product Name or Description |
| 8mm-12m |
12 meter 8mm |
| 8mm-60m |
60 meter 8mm |
| 8mm-90m |
90 meter 8mm |
| 8mm-112m |
112 meter 8mm |
| 8mm-160m |
160 meter 8mm |
| mammoth |
Exabyte mammoth |
| 3480 |
3480 |
| 3490 |
3490 |
| 3490E |
3490E |
| 3495 |
IBM Magstar native |
| 4480 |
STK Timberline native |
| 4490 |
STK Redwood native |
| DLT2000 |
DLT2000 |
| DLT2000XT |
DLT2000XT |
| DLT4000 |
DLT4000 |
| DLT7000 |
DLT7000 |
| DDS1 |
DAT |
| DDS2 |
DAT |
| DDS3 |
DAT |
| D2-S |
Ampex DST-310 small format |
| D2-M |
Ampex DST-310 medium format |
| D2-L |
Ampex DST-310 165GB large format |
| DFT |
Sony GY-10 |
| ISO9660 |
CDROM |
|
Partition Names
The ADI interface assumes that there is a standard set of names used
for partitioned media. Here are the tokens that are used for naming
partitions.
| Token |
Description |
| PART 1 |
The first partition on the media. On a linear media such as
a tape, PART 1 is defined to be the one closest to
the physical beginning of the media. On a non-linear media such as a
disk, PART 1 is defined to be the lowest
"numbered" or "lettered" partition, using whatever
standard partitioning mechanism exists on that media. |
| PART 2 |
The second partition on the media. On a linear media such
as a tape, PART 2 is defined to be the one
immediately following PART 1 on the media. On a
non-linear media such as a disk, PART 2 is defined
to be the second lowest "numbered" or "lettered"
partition, using whatever standard partitioning mechanism exists on
that media. Note that PART 2 does not refer to the
next partition that is in use, it refers to the next partition. For
example, a disk drive might define partitions 1 through 16 but only
normally use partitions 1, 6, 8, and 10. PART 2
would refer to partition 2, not partition 6. |
| PART 3 |
As you might expect, the pattern continues... |
|
Attribute Names
Here are various attributes that are used in OpenVault, where they are
used, and what they mean.
| Attribute Name |
Where Used |
Possible Values |
Req? |
Description |
| ReadBandwidth |
ADI config command, attr clause |
numeric, in bytes per second |
yes |
The total effective bandwith that an application should be
able to sustain when reading from that drive using the given capability
set. |
| WriteBandwidth |
ADI config command, attr clause |
numeric, in bytes per second |
yes |
The total effective bandwith that an application should be
able to sustain when writing to that drive using the given capability
set. |
| Capacity |
ADI config command, attr clause |
numeric, in megabytes |
yes |
The total storage capacity of the cartridge that an
application should be able to expect when accessing that drive using
the given capability set. |
| Blocksize |
ADI config command, attr clause |
numeric, in bytes |
yes |
The I/O size that would best utilize the drive/cartridge
combination when using that drive with the given capability set. |
| LoadTime |
ADI config command, attr clause |
numeric, in seconds |
yes |
The number of seconds between the time a cartridge is first
inserted into a drive and the time that the drive is ready to
read/write data. |
| SlotTypeName |
ADI config command, attr clause |
Slot Type Name token |
yes |
A supported form factor when the drive is using the
given capability set. |
| CartridgeTypeName |
ADI config command, attr clause |
Cartridge Type Name token |
yes |
A supported cartridge type when the drive is using
the given capability set. |
| BitFormat |
ADI config command, attr clause |
Bit Format token |
yes |
A supported bit format when the drive is using the
given capability set. |
| NominalLoad |
ALI config command, perf clause |
numeric, in seconds |
yes |
The approximate time it will take for the library to move a cartridge
from its home location to a drive, or back, not
including drive load/unload time.
This is analogous to the "nominal seek time" of a disk drive,
and is defined to be the total real time to execute a large number of
cartridge load/move operations randomly spread through the physical
space of the library divided by the number of such operations
performed. |
|
