Storage system with procedure for monitoring low level status codes, deriving high level status codes based thereon and taking appropriate remedial actions

A controller of a storage system for computer data enables diagnosis of errors and status monitoring of the storage system. The controller is enabled to categorize errors according to severity and to analyze low-level errors so as to trigger a combination of high level error conditions.

TECHNICAL FIELD 
The present invention relates to devices for storing computer data and 
relates particularly to diagnostics and status monitoring. 
BACKGROUND ART 
It is known to provide status monitoring in a disc drive and U.S. Pat. No. 
5,450,609 describes one such system in which an array of disc drives 
includes a facility for status monitoring and for warning the user of a 
problem. The warning facility described is not very different in scope 
from the known facility on existing tape drives of a warning light 
indicating failure of a backup operation. 
DISCLOSURE OF INVENTION 
The present invention aims to provide a status monitoring and diagnostic 
facility for a storage device which takes account of the fact that the 
storage medium is removable and which diagnoses a wider range of error 
conditions than simply flagging imminent failure. 
According to the present invention we provide a system for storing computer 
data comprising: 
a storage device having means for reading data from and writing data to 
removable media; 
and a controller, 
wherein the storage device comprises: 
means to perform error diagnosis and to translate low-level error 
indicators into high level error conditions and wherein the high level 
error conditions are categorised according to severity; 
means to communicate occurrence of these high level error conditions to the 
controller to trigger the provision of error messages to the user. 
Embodiments of the present invention provide a facility to inform the user 
of errors occurring during a backup operation and to group errors into 
categories according to severity. This enables the provision of messages 
to the user which are primarily for information as well as messages to 
indicate more serious error conditions. This feature also enables the user 
to prioritise error recovery steps according the severity of the error 
conditions if there is more than one existing at the same time. 
The term `low-level error indicator` is intended to cover both error codes 
and other relevant triggers generated in the storage device. Low-level 
error codes cover items such as unrecoverable read and/or write errors but 
there are also other relevant triggers for high level error conditions 
such as the rate at which data is being written, data relevant to the 
media being used etc. Low-level error indicators are normally generated by 
the firmware in the storage device. 
In the embodiment to be described, the storage device is a tape drive, but 
the invention applies also to other storage devices with removable media 
eg. optical disc drives. 
The controller may be backup controller software running on a host 
computer. Alternatively the system may be part of network in which the 
controller is backup software running on a backup server on the network. 
However, the invention is not limited to these alternatives and the 
controller may be implemented in software and/or hardware and may be in a 
general purpose computer or a dedicated device, whether standalone or 
connected to a network. 
In the embodiment to be described, the high level error conditions are 
categorised into three classes according to severity. The classes are: 
Information, Warning and Critical. 
If there is a plurality of error conditions occurring at the same time, 
error messages may be ordered according to the relative severity of the 
pertaining error conditions. This feature may help the user in 
prioritising the necessary error recovery steps. 
The low-level error indicators may be grouped into functional types and the 
high level error conditions may be communicated according to what 
functional type of low-level error has occurred. This feature may 
facilitate specifying the relationship between low-level error indicators 
and the high level error conditions, which task would normally be carried 
out by the storage device manufacturer. 
Preferably the system comprises means to automatically initiate a 
predetermined sequence of error recovery steps according to the type of 
high level error conditions identified. In this way there may be provision 
for automatically triggering specific error recovery steps without manual 
intervention of the user. 
In the embodiment to be described, the error status information is stored 
in the storage device in a standardised format. In this way, the invention 
provides a technique whereby the way in which errors are detected and 
categorised for a particular storage device is device-specific and can be 
decided by the device manufacturer but within the context of a 
standardised scheme which enables all devices complying with the 
standardised format to provide the user with consistent error indications. 
There are different ways in which the controller may receive error 
information from the storage device. In one embodiment, the system is 
configured so that the occurrence of high level error conditions is 
communicated to the controller at predetermined points in a storage 
operation. In another embodiment, the system is configured so that the 
occurrence of high level error conditions is communicated to the 
controller whenever a new error is indicated by the storage device. 
The system may comprise a plurality of storage devices, such as in an 
autoloader or a coordinated array of storage devices. 
According to another aspect of the present invention we provide a system 
for storing computer data comprising: 
a storage device having means for reading data from and writing data to 
removable media; 
and a controller, 
wherein the storage device comprises: 
means to perform error diagnosis and to translate low-level error 
indicators into high level error conditions; 
wherein selected low-level error indicators cause communication of a 
combination of high level error conditions; 
means to communicate occurrence of these high level error conditions to the 
controller to trigger the provision of error messages to the user. 
In known systems for storing computer data which include a storage device 
communicating with one or more host devices using a SCSI link, or bus, the 
occurrence of a low-level error indicator triggers a single high level 
error message. According to the above aspect of the present invention, a 
combination of high level error conditions may result from selected 
low-level error indicators thus providing a more flexible system and 
allowing a more extensive set of error messages to be provided to a user.

The invention will also be described, by way of example, with reference to 
tables reproduced at the end of this description in which: 
Table 1 shows the error conditions relating to particular flags; 
Table 2 shows the format of the Log Sense page; 
Table 3 shows the format of the Mode Sense page. 
BEST MODE FOR CARRYING OUT THE INVENTION, & INDUSTRIAL APPLICABILITY 
Referring to FIG. 1, a tape drive 10 is directly connected to a host 
computer 12. The tape drive 10 receives data to be backed up from the host 
computer 12 and sends saved data back to the host when requested. A 
standard SCSI (`Small Computer System Interface`) interface is used to 
interconnect the tape drive 10 with the host computer 12. 
FIG. 2 is a functional block diagram of the system represented in FIG. 1. 
In FIG. 2, the tape drive 10 is arranged to store and retrieve data in 
accordance with the digital data storage (DDS) standard format. The tape 
drive 10 comprises a host interface unit 21 for interfacing the drive 10 
with a host computer 12 via a standard SCSI bus 39. A data formatter 22 in 
the tape drive 10 processes user data records and separator marks into and 
out of indexed groups, compresses/decompresses data in a known fashion and 
effects low-level signal processing, as specified in the DDS format. The 
low-level processing converts streams of bytes from the groups into track 
signals ready for recording data to tape and reconverts track signals from 
tape back into byte streams for reconstructing the groups. The tape drive 
10 further comprises a deck 29 of known type comprising electronic 
circuitry for controlling recording heads and tape operations for writing 
data to and reading data from a tape medium 295. The tape drive 10 also 
comprises a tape drive controller 23 for controlling the operation of the 
other elements of the drive in response to commands received from the host 
12 via the host interface unit 21. 
The drive 10, controlled by the tape drive controller 23, is arranged to 
respond to SCSI commands from backup software 36 running the host computer 
12 to load/unload a tape, to store a data record or separator mark, to 
search for selected separator marks or records, and to read back the next 
record and to compress/decompress data records. These functions are 
standard tape drive functions and, as such, will not be considered in 
further detail in this description. For further, more detailed information 
on DDS tape drives and the respective data format, the reader is referred 
to European Patent Application EP459041A1. 
In accordance with the present embodiment, the tape drive controller 23 
incorporates further functionality, which a storage device has hitherto 
not provided, to support status monitoring and tape drive diagnostics 
capabilities. This functionality is provided by appropriate firmware 
processes 24 embedded in the tape drive controller 23. Of the processes: a 
first process 242 monitors the status of pre-determined functions in the 
tape drive 10 by receiving low level system status codes returned by the 
other elements of the drive during the operation of the tape drive and, in 
response, sets flags to indicate possible problems; a second process 244 
interprets the flags in a pre-determined manner and generates one or more 
predetermined high level status or error codes; and a third process 246 
prioritizes the high level codes, where more than one code exists, in 
accordance with a pre-defined criteria and stores the results in an area 
of random access memory (RAM) 25 accessible by the tape drive controller 
23. Once stored, the high level codes may be forwarded to the host 
computer 12, for example by "polling", as described below in more detail. 
The low level codes, the flags, the high level codes and the priority 
criteria are also described in detail below. 
As also illustrated in FIG. 2, the host computer 12 comprises a standard 
computing platform running under the control of an operating system 37 
such as Windows NT 4.0. Backup controller software 36, stored in main 
memory 31 and running on a central processing unit 35, is a software 
process written, for example, in the C.sup.++ programming language. The 
backup software 36 is arranged to control the host computer 12 to operate 
in accordance with the present embodiment. The operating system 37 of the 
host computer 12 includes: a network driver 32 for transmitting and 
receiving data, for example in TCP/IP format, to and from a network (not 
shown); a display driver 33, such as a video graphics array (VGA) driver, 
to transmit display signals to a display screen 38; and a SCSI driver 34, 
to transfer commands and data between the host computer 12 and the tape 
drive 10. The drivers provided support respective standard hardware 
interfaces. 
The backup controller software 36 is arranged to control the host computer 
12 to retrieve high level status or error codes which have been stored in 
the memory 25 from the tape drive 10 by polling the tape drive 10 
regularly. Other methods of moving the data from the tape drive 10 to the 
host computer 12 are described below. Further, the backup controller 
software 36 is arranged to process any received high level status or error 
codes and forward to a user appropriate, pre-defined error or action 
messages. Such messages may be forwarded for display to the user on the 
display screen 38, and/or across a network to a remote network console 
(not shown) as necessary. 
In accordance with the present embodiment, there are 64 flags defined to 
cover a wide range of error conditions and these are as shown in Table 1. 
The column headings in Table 1 are as follows: 
No.--this is simply the flag number; 
Flag--this is the name of the flag and indicates the error to which it 
relates; 
Type--this indicates the seriousness of the error: 
"I"=Information: a suggestion to the user; 
"W"=Warning: the user is advised to take action. Performance or data may be 
at risk; 
"C"=Critical!: action should be taken immediately; 
Required Host Message--this is the text of the message which should be 
relayed to the user eg. by display on the screen 38 of the host computer 
12; 
Cause--this indicates the cause of the error. 
The flags are grouped into the following categories: 
Flags 1 to 19: For tape drive write/read management 
Flags 20 to 29: For cleaning management 
Flags 30 to 39: For tape drive hardware errors 
Flags 40 to 49: For tape autoloader errors 
Flags 50 to 64: Currently unassigned for future use 
The specific conditions for any one flag to be set and cleared are 
drive-specific and are defined by the drive manufacturer. If a drive 
cannot support the recognition of all the flag conditions, then 
unsupported flags may remain unset. 
Low-level error indicators may be grouped into functional types with a set 
of possible low-level error indicator codes being assigned to each group. 
The relevant functional types include: 
Unrecoverable write error codes; 
Unrecoverable read error codes; 
Tape management error codes; 
Hardware error codes; 
Recoverable write error codes; 
Recoverable read error codes. 
There are also other groups in addition to the above. 
If such grouping is done, then flags may be set according to which type of 
low-level error indicator has occurred. For example, all recoverable write 
error codes would cause a particular flag to be set, in fact Flag 1 in 
Table 1 in this embodiment. This feature relieve the tape drive 
manufacturer of the need to define a mapping from every single low-level 
error indicator to a particular flag. 
Furthermore, the system may be configured so that a combination of high 
level error conditions result from selected low-level error indicators. 
Thus two or more flags may be set in order to provide a plurality of 
relevant error messages to the user. 
A well-known feature of the standard SCSI interface is the use of `log 
sense` pages to record peripheral status information and `mode sense` 
pages to record functional and configuration settings. 
The error information contained in Table 1 is stored by the tape drive 10 
in a `Log Sense` page in memory 25. The format of the Log Sense page is 
shown in Table 2. Each line in the Log Sense page represents one byte of 
data and the entries are numbered down the lefthand side of Table 2. A 
description of the entries is as follows: 
Entry 0--the name of the page (2e in this example); 
Entry 1--reserved for future use; 
Entry 2--the length of the particular page (2 bytes long); 
Entry 3--the remainder of the page length; 
Entry 4--the SCSI standard uses parameters and this is the name of the 
current parameter (2 bytes long). In this embodiment, each parameter 
corresponds to one of the flags in Table 1; 
Entry 5--the remainder of the parameter name; 
Entry 6--the parameter control byte. The fields are explained below. The 
terms `sense key` and `sense code` are commonly used in relation to the 
SCSI standard to refer to codes for the type of error and details of the 
error, respectively: 
DU=Disable Update: a value of zero means that the tape drive will not 
update the log parameter value (Entry 8 below). A value of one means that 
the tape drive will not update the log parameter value except in response 
to a Log Select command that specifies a new value for the log parameter. 
The DU bit is undefined and ignored if the PC bit (part of the page code) 
in the Log Sense command is set to 0.times.00 (as in this embodiment); 
DS=Disable Save: a value of zero means that the tape drive supports saving 
for that log parameter. A value of one means means that saveable 
parameters are not supported; 
TSD=Tape drive Save Disable: a value of zero means that the tape drive 
provides a tape drive-defined method for saving log parameters. A value of 
one means that the tape drive does not provide a tape drive-defined method 
of saving log parameters; 
ETC=Enable threshold comparison: a value of one means that comparison to 
the threshold value is performed. A value of zero means that a comparison 
is not performed; 
TMC=Threshold Met Criteria: defines the basis for the comparison of the 
parameter value. Only valid if ETC=1. If the ETC=1 and the comparison is 
true, a check condition will be generated. The Sense key is then set to 
UNIT ATTENTION and the additional sense code is set to THRESHOLD CONDITION 
MET; 
LP=List Parameter: indicates the format of the log parameter. A value of 
zero means that the parameter is a data counter. A value of one means that 
the parameter is a list parameter, and then the ETC and TMC field must be 
set to zero; 
Entry 7--the length of the current parameter; 
Entry 8--the actual parameter. In this case it is the first flag, namely 
the Read Flag. In this embodiment only one bit is used for each flag; 
Entry 9 and so on--corresponding entries for the subsequent parameters 
(flags). 
There are two methods by which the host computer 12 can access error 
information in the tape drive 10. The first method is "polling" where the 
Log Sense page is read from the tape drive at the following times as a 
minimum: 
1. Immediately after a SCSI Check Condition/Request Sense cycle. This is a 
standard cycle in which the drive makes an error status report and if 
there is an error this is indicated as a `Check Condition`. The host then 
sends a `Request Sense` command to get details of the error. 
2. At the end of each tape when the backup/restore job spans multiple 
tapes. If the tape is to be ejected then the Log Sense page must be read 
before ejection. 
3. At the end of a backup/restore job. 
It is also recommended to poll the Log Sense page every 60 seconds while 
the tape drive 10 is idle. 
The second access method is to use the SCSI `Mode Select` command to enable 
the "Check Condition" mode, so that the tape drive 10 will report a Check 
Condition on the next SCSI command after one or more flags are set. If 
this SCSI command should return a Check Condition due to an actual error, 
then this will override the Check Condition `forced` by the Mode Select 
command. The Log Sense page will therefore be read from the tape drive 10 
after every Check Condition/Request Sense cycle (both forced check 
conditions and error check conditions). The Request Sense extended sense 
code (this is the code reported by the tape drive 10) for a check 
condition is 5D00, and the command that triggered this Check Condition 
will have been executed, thus the backup controller software 36 will not 
repeat the command that triggered a Check Condition. 
The recommended method is "check condition" rather than "polling" since 
this guarantees that the backup controller software 36 will be made aware 
of any flag being set. With "polling" there are theoretical corner cases 
where flag information could be missed, though the higher the polling 
frequency the less chance there is of this happening. 
The method of access to the tape drive 10 can be configured via the SCSI 
bus, based on a new Mode Sense page. The interface can be configured via 
the Mode Select command using the same page format to write the 
configuration as to read it (Mode Sense command). The format of this new 
Mode Sense page is as shown in Table 3. 
Again each entry in the Mode Sense page is one byte long. The entries are 
as follows: 
Entry 0--the name of the page (1C in this example); 
Entry 1--the length of the particular page; 
The following fields are in the remainder of the Mode Sense page: 
DExcpt: When this bit is set to zero the reporting method indicated by the 
MRIE field is used. When this bit is set to one this indicates that the 
tape drive 10 will ignore the MRIE field (so that the backup controller 
software 36 must poll the Log Sense page). Thus to enable "check 
condition" mode, this bit must be set to zero. 
In this embodiment, the default setting is 1, and this is configurable via 
Mode Select 
Test: When this bit is set to zero, this indicates that the tape drive 10 
will not generate any false flags. When this bit is set to one, the tape 
drive 10 will set a false flag based on the MRIE and Interval Timer flags. 
Thus the next SCSI command after the Mode Select command will return Check 
Condition, with sense key set to UNIT ATTENTION and extended sense code 
set to 5DFF (a test code). If both the Test and DExcpt bits are set to 
one, then the Mode Select command will return Check Condition, with sense 
key set to Illegal Request and extended sense code set to INVALID FIELD in 
the Parameter List. 
In this embodiment, the default setting is 0, configurable via Mode Select 
Perf: When this bit is set to zero, this indicates that flag setting 
operations that can cause delays are acceptable. When this bit is set to 
one, the tape drive 10 will not cause delays while setting flags (this may 
cause the tape drive 10 to disable some or all of the flag setting 
operations). 
In this embodiment, the default setting is 0, not changeable via Mode 
Select 
LogErr: When this bit is set to zero, this indicates that the logging of 
flags set within a tape drive 10 is vendor specific. When this bit is set 
to one, the tape drive 10 will log flags set. 
In this embodiment, the default setting is 0, not changeable via Mode 
Select 
MRIE: This field indicates the method used by the tape drive 10 to report 
flags set. The priority of reporting flags set is tape drive 10 specific. 
If the access method being used is the one described above using the Mode 
Select command to enable the "Check Condition" mode, so that the tape 
drive 10 will report a Check Condition on the next SCSI command after one 
or more flags are set then, in the event that the SCSI command should 
return a Check Condition due to an actual error, then this will override 
the forced Check Condition. The values defined for this field are: 
0.times.1: No reporting of flags set 
0.times.2: Generate Unit Attention: tape drive 10 returns Check Condition 
on the next SCSI command after a flag is set, with the sense key set to 
UNIT ATTENTION and the extended sense code set to 5D00. The command that 
triggered the forced Check Condition will not have been executed, and thus 
needs to be repeated; 
0.times.3: Conditionally generate Recovered Error: depending on the value 
of tape drive 10 error recovery settings, the tape drive 10 returns Check 
Condition on the next SCSI command after setting of a flag was detected, 
with the sense key set to RECOVERED ERROR and the extended sense code set 
to 5D00. The command that has triggered the forced Check Condition will 
have been executed correctly, and thus does not need to be repeated; 
0.times.4: Unconditionally generate Recovered Error: regardless of the 
value of the tape drive 10 error recovery settings, the tape drive 10 
returns Check Condition on the next SCSI command after setting of a flag 
was detected, with the sense key set to RECOVERED ERROR and the extended 
sense code set to 5D00. The command that has triggered the forced Check 
Condition will have been executed correctly, and thus does not need to be 
repeated; 
0.times.5: Generate No Sense: tape drive 10 returns Check Condition on the 
next SCSI command after setting of a flag was detected, with the sense key 
set to NO SENSE and the extended sense code set to 5D00. The command that 
has triggered the check condition will have been executed correctly, and 
thus does not need to be repeated; 
0.times.6: Only report on request: tape drive 10 will preserve the flag(s) 
set. The backup controller software 36 then polls the tape drive 10 using 
the Log Sense command. 
In this embodiment, the default setting is 3, not changeable via Mode 
Select. 
Interval Timer: When this field is set to zero, this indicates that the 
tape drive 10 will only set a flag once. When this field is set to 
non-zero, the value indicates the period in 100 millisecond increments for 
resetting a flag. The tape drive 10 will not set flags more frequently 
than the specified timer interval and will set flags as soon as possible 
after the timer interval has elapsed. A value of 0.times.FFFFFFFF in the 
field indicates that the timer interval is tape drive 10 specific. 
In this embodiment, the default setting is 0, not changeable via Mode 
Select. 
Report Count: When this field is set to zero, this indicates that there is 
no limit to the number of times the tape drive 10 will report a flag being 
set (assuming that Interval Timer is set to non-zero). When this field is 
set to non-zero, this indicates the number of times to report a flag being 
set. 
In this embodiment, the default setting is 0, not changeable via Mode 
Select. 
Every time the Log Sense page is read from the tape drive 10, the backup 
controller software 36 reads all 64 flags to discover which are set (there 
may be more than one). There may also be data associated with a set flag 
in the remainder of the flag byte, which should also be read. The flags 
will automatically be cleared by the tape drive 10 without action from the 
software, and thus any set flags read by the backup controller software 36 
indicate a new event. The software therefore will not latch any flag 
states but will always action any set flag detected. 
A particular backup controller may be connected to more than one tape drive 
10. In addition, for each tape drive 10, there will be a plurality of tape 
cassettes used for backing up data. Each tape cassette is given a 
`software label` to identify it. 
For every flag that is set, the backup controller software 36 will log the 
error message specified in Table 1 along with details to identify which 
tape drive 10 the error refers to, and the software label of the media for 
media related actions (flags 4 and 7). The severity of the error is 
identified based on the flag Type field in Table 1, and when multiple 
flags are set simultaneously they are listed in ascending order of 
severity ie. Information/Warning/Critical). 
For every flag that is set, the backup controller software 36 notifies the 
user through its normal notification methods (e.g. broadcast, email, SNMP, 
etc.), displaying the specified error message along with details to 
identify which tape drive 10 the error refers to, and the software label 
of the media for media related actions (flags 4 and 7). The notification 
identifies the severity of the error, and when multiple flags are set 
simultaneously they are listed in ascending order of severity 
(Information/ Warning/ Critical). It is possible to include error message 
filters in the backup controller software 36 so that only errors of a 
certain severity are notified to the user and/or specifying the mode of 
notification of errors of different severity. When multiple flags are set 
simultaneously, they may be associated together as a single error event, 
for example by displaying all of the associated error messages together in 
one dialogue box. 
The backup controller software 36 does not fail a backup job based on the 
flag information. Rather, setting of the flags provides preventative 
maintenance information such that the user or the backup controller 
software 36 can initiate actions to prevent the failure occurring at all, 
and thus increases the reliability of the backup system. This facility 
also provides assistance in diagnosing/recovering a failing backup job. 
The backup controller software 36 may be configured to automate the 
recommended maintenance/recovery actions, particularly if there are 
multiple tape drive 10s or autochangers present. For example, it could 
trigger performance of a cleaning cycle for flags 20 and 21, or a tape 
copy for flags 4 and 7, and retire the suspect media. 
Typically, the backup controller software will be loaded into the memory of 
the host computer from a computer readable data carrying medium such as a 
floppy disk, mini-disk or optical disk (CD ROM). Alternatively, the 
software could be down-loaded accross a network such as the Internet from 
a source such as a World Wide Web or FTP server. 
The above embodiment relates to a tape drive 10 but it will be understood 
that the present invention is relevant to any storage device which uses 
removable media and so is also relevant to optical disc drives. 
TABLE 1 
__________________________________________________________________________ 
No 
Flag Type 
Required Host Message 
Cause 
__________________________________________________________________________ 
1 
Read W The tape drive 10 is having problems 
The drive is having 
reading data. No data has been lost, 
severe trouble reading 
but there has been a reduction in the 
capacity of the tape. 
2 
Write 
W The tape drive 10 is having problems 
The drive is having 
writing data. No data has been lost, 
severe trouble writing 
but there has been a reduction in the 
capacity of the tape. 
3 
Hard W The operation has stopped because an 
The drive had a hard 
Error error has occurred while reading or 
read or write error 
writing data which the drive cannot 
correct. 
4 
Media 
C Your data is at risk: 
Media performance is 
1. Copy any data you require from 
severely degraded 
this tape. 
2. Do not use this tape again. 
3. Restart the operation with a 
different tape. 
5 
Read C The tape is damaged or the drive is 
The drive can no 
Failure faulty. Call the tape supplier helpline. 
longer read data from 
the tape 
6 
Write 
C The tape is from a faulty batch or the 
The drive can no 
Failure tape drive 10 is faulty: 
longer write data to 
1. Use a good tape to test the drive. 
the tape 
2. If the problem persists, call the 
tape drive 10 supplier helpline. 
7 
Media 
W The tape cartridge has reached the 
The media has 
Life end of its useful life: 
exceeded its specified 
1. Copy any data you need to another 
life 
tape 
2. Discard the old tape. 
8 
Not Data 
W The tape cartridge is not data-grade. 
The drive has not been 
Grade Any data you back up to the tape is at 
able to read the MRS 
risk. stripes 
Replace the cartridge with a data- 
grade tape. 
9 
Write 
C You are trying to write to a write- 
Write command is 
Protect protected cartridge. 
attempted to a write 
Remove the write-protection or use 
protected tape 
another tape. 
10 
No I You cannot eject the cartridge 
Manual or s/w unload 
Removal because the tape drive 10 is in use. 
attempted when 
Wait until the operation is complete 
prevent media removal 
before ejecting the cartridge. 
on 
11 
Cleaning 
I The tape in the drive is a cleaning 
Cleaning tape 
Media cartridge. encountered during 
If you want to back up or restore, 
backup or restore 
insert a data-grade tape. 
12 
Unsup- 
I You have tried to load a cartridge of 
Attempted loaded of 
ported a type which is not supported by this 
unsupported tape 
Format drive. format, e.g. DDS2 in 
The cartridge has been automatically 
DDS1 drive 
ejected. 
13 
Snapped 
C The operation has failed because the 
Tape snapped in the 
Tape tape in the drive has snapped: 
drive 
1. Discard the old tape. 
2. Restart the operation with a 
different tape. 
20 
Clean 
C The tape drive 10 needs cleaning: 
The drive thinks it has 
Now 1. If the operation has stopped, eject 
a head clog, or needs 
the tape and clean the drive 
cleaning 
2. If the operation has not stopped, 
wait for it to finish and then clean the 
drive. 
21 
Clean 
W The tape drive 10 is due for routine 
The drive is ready for 
Periodic 
cleaning: a periodic clean 
1. Wait for the current operation to 
finish. 
2. Then use a cleaning cartridge. 
22 
Expired 
C The last cleaning cartridge used in the 
The cleaning tape has 
Cleaning 
tape drive 10 has worn out: 
expired 
Media 1. Discard the worn out cleaning 
cartridge. 
2. Wait for the current operation to 
finish. 
3. Then use a new cleaning cartridge. 
30 
Hardware 
C The tape drive 10 has a hardware 
The drive has a 
A fault: hardware fault which 
1. Eject the tape or magazine. 
is not read/write 
2. Reset the drive (hold the unload 
related. 
button down for 5 seconds). 
3. Restart the operation. 
31 
Hardware 
C The tape drive 10 has a hardware 
The drive has a 
B fault: hardware fault which 
1. Turn the tape drive 10 off and then 
is not read/write 
on again. related. 
2. Restart the operation. 
3. If the problem persists call the 
tape drive 10 supplier helpline. 
32 
Interface 
W The tape drive 10 has a problem with 
The drive has 
the SCSI interface: 
identified an 
1. Check the cables and cable 
interfacing fault 
connections. 
2. Restart the operation. 
33 
Eject 
C The operation has failed: 
Error recovery action 
Media 1. Eject the tape or magazine. 
2. Insert the tape or magazine again. 
3. Restart the operation. 
34 
Download 
W The firmware download has failed 
Firmware download 
Fail because you have tried to use the 
failed 
incorrect firmware for this tape drive 
10. 
Obtain the correct firmware and try 
again. 
40 
Loader 
C The changer mechanism is having 
Loader mech. is 
Hardware 
difficulty communicating with the 
having trouble 
A tape drive 10: communicating with 
1. Turn the autoloader off then on. 
the tape drive 10 
2. Restart the operation. 
3. If problem persists, call the tape 
drive 10 supplier helpline. 
41 
Loader 
C A tape has been left in the autoloader 
Stray tape left in 
Stray by a previous hardware fault: 
loader after previous 
Tape 1. Insert an empty magazine to clear 
error recovery 
the fault. 
2. If the fault does not clear, turn the 
autoloader off and then on again. 
3. If the problem persists, call the 
tape drive 10 supplier helpline. 
42 
Loader 
W There is a problem with the 
Loader mech. has a 
Hardware 
autoloader mechanism. 
hardware fault 
B 
43 
Loader 
C The operation has failed because the 
Tape changer door 
Door autoloader door is open: 
open 
1. Clear any obstructions from the 
autoloader door. 
2. Eject the magazine and then insert 
it again. 
3. If the fault does not clear, turn the 
autoloader off and then on again 
4. If the problem persists, call the 
tape drive 10 supplier helpline. 
64 
__________________________________________________________________________ 
TABLE 2 
______________________________________ 
7 6 5 4 3 2 1 0 
______________________________________ 
0 Page Code 0x2e 
1 Reserved (0) 
2 Page Length 
3 
4 Parameter Code (1) 
5 
6 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
7 Parameter Length (1) 
8 Read Flag 
9 Parameter Code (2) 
10 
11 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
12 Parameter Length (1) 
13 Write Flag 
14 Parameter Code (3) 
15 
16 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
17 Parameter Length (1) 
18 Hard Error Flag 
19 Parameter Code (4) 
20 
21 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
22 Parameter Length (1) 
23 Media Flag 
24 Parameter Code (5) 
25 
26 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
27 Parameter Length (1) 
28 Read Failure Flag 
29 Parameter Code (6) 
30 
31 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
32 Parameter Length (1) 
Write Failure Flag 
33 Parameter Code (7) 
35 
36 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
37 Parameter Length (1) 
38 Media Life Flag 
39 Parameter Code (8) 
40 
41 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
42 Parameter Length (1) 
43 Not Data Grade Flag 
44 Parameter Code (9) 
45 
46 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
47 Parameter Length (1) 
48 Write Protect Flag 
49 Parameter Code (0xA) 
50 
51 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
52 Parameter Length (1) 
53 No Removal Flag 
54 Parameter Code (0xB) 
55 
56 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
57 Parameter Length (1) 
58 Cleaning Media Flag 
59 Parameter Code (0xC) 
60 
61 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
62 Parameter Length (1) 
63 Unsupported Format Flag 
64 Parameter Code (0xD) 
65 
66 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
67 Parameter Length (1) 
68 Tape Snapped Flag 
. . . Parameter Code (xx) 
. . . DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
. . . Parameter Length (1) 
. . . xxxxxxxxxxxxxxx 
99 Parameter Code (0x14) 
100 
101 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
102 Parameter Length (1) 
103 Clean Now Flag 
104 Parameter Code (0x15) 
105 
106 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
107 Parameter Length (1) 
108 Clean Periodic Flag 
109 Parameter Code (16) 
110 
111 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
112 Parameter Length (1) 
113 Expired Cleaning Media Flag 
. . . Parameter Code (xx) 
. . . DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
. . . Parameter Length (1) 
. . . xxxxxxxxxxxxxxx 
149 Parameter Code (1E) 
150 
151 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
152 Parameter Length (1) 
153 Hardware A Flag 
154 Parameter Code (1F) 
155 
156 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
157 Parameter Length (1) 
158 Hardware B Flag 
159 Parameter Code (20) 
160 
161 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
162 Parameter Length (1) 
163 Interface Flag 
164 Parameter Code (21) 
165 
166 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
167 Parameter Length (1) 
168 Eject Media Flag 
169 Parameter Code (21) 
170 
171 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
172 Parameter Length (1) 
173 Download Fail Flag 
. . . Parameter Code (xx) 
. . . DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
. . . Parameter Length (1) 
. . . xxxxxxxxxxxxxxx 
199 Parameter Code (0x28) 
200 
201 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
202 Parameter Length (1) 
203 Loader Hardware A Flag 
204 Parameter Code (0x29) 
205 
206 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
207 Parameter Length (1) 
208 Stray Tape Flag 
209 Parameter Code (0x2A) 
210 
211 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
212 Parameter Length (1) 
213 Loader Hardware B Flag 
214 Parameter Code (0x2A) 
215 
216 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
217 Parameter Length (1) 
218 Loader Door Flag 
. . . Parameter Code (xx) 
. . . DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
. . . Parameter Length (1) 
. . . xxxxxxxxxxxxxxx 
319 Parameter Code (40) 
320 
321 DU(0) DS(1) TSD(0) 
ETC(0) 
TMC(0) 
Res(0) 
LP(0) 
322 Parameter Length (1) 
323 xxxxxxxxxxxxxxx 
______________________________________ 
TABLE 3 
______________________________________ 
7 6 5 4 3 2 1 0 
______________________________________ 
0 Page Code (0x1C) 
1 Page Length (0x0A) 
2 Perf Reserved DExcpt 
Test Reserved 
LogErr 
3 Reserved MRIE 
4 Interval Timer 
6 
7 
8 Report Count 
9 
10 
11 
______________________________________