Discover is a comprehensive, easy-to-use, disk storage management tool
for HP Nonstop systems
Click here to download Discover
Discover key features include:
for managing disk resources on HP NonStop servers
Discover provides a safe and efficient mechanism for monitoring disk
resource usage on HP NonStop servers. It replaces manual methods of
tracking disk and file growth, reduces the risk of human error, and
frees up operations and support staff for other tasks.
Discover continuously monitors disk and file usage, and predicts
potential disk full and file full conditions before they occur. You can
configure Discover to automatically invoke corrective actions, or to
alert an operator that manual intervention is required.
By anticipating such events, Discover helps eliminate application
outages due to unforeseen disk resource problems.
In addition, Discover is work-flow oriented. It organizes "action
items" which are required in order to ensure the availability of your
Prevention of application outages due to disk or
file full conditions
Most applications depend on the availability of sufficient disk space
in order to function correctly. If a disk volume becomes short of free
space, an application may not be able to allocate the disk space
required in order to continue running.
In addition, individual disk files may only grow to a pre-configured
size. If an application continually adds new data to a file it will
eventually encounter a "no space" error condition - even if there is
free space available on the disk.
Either of these situations can cause part, or all, of an application to
become unavailable. Discover enables you to avoid these conditions by
taking corrective actions before they occur.
monitoring of disk utilization
The Discover monitor is a NonStop process pair that continually runs as
a background task. At pre-defined intervals, it collects and records
data on disk volume and file usage. The data is used to predict future
disk and file usage, and the time at which disks and files will become
full. The predictions made by Discover are also recorded so that actual
and predicted usage can be compared for accuracy.
The monitor calculates expected growth over the next hour, day, week,
and month. For disk files, it compares the expected growth to the
configured maximum size of the file. For disk volumes, it compares the
expected growth to the available space on the volume.
technology for improved disk space allocation
Discover includes SpaceMaker technology which can:
Increase the amount of available free space on a
Prevent extent allocation failures on growing files
- Typically, a disk volume contains many files
that use more
disk space than they actually need. When Discover detects such a file,
and the file is not growing, it de-allocates the unused disk space.
This makes the space available for use by other files.
- As a file grows, it is normally allocated
space as it is needed. When the file's space is all used up, the
operating system allocates a new extent to contain data added to the
file. The problem with this approach is that if the operating system
cannot find space for a new extent, an error is returned to the
application which will typically fail.
To avoid this type of problem, Discover can pre-allocate disk space to
growing files. For example, Discover can be configured to pre-allocate
space a week ahead of when it is needed. When Discover predicts that a
file will require more space within a week, it allocates the space
ahead of time.
There are two benefits to this approach. If the space is available, it
is allocated immediately guaranteeing that the file will have enough
space to accommodate the anticipated growth. If the space is not
available, the system administrator will receive a warning, giving him
time to take corrective measures.
Discover keeps track of key file attributes such as the file owner,
security setting, AUDIT flag, BUFFERED flag etc.. Discover detects when
a file attribute is changed. You can specify which corrective measures
should be taken when the condition is detected.
In addition to changes in file attributes, Discover also detects files
that have been marked as broken, corrupted, or which require
of key sequenced files
Discover performs a health check on key sequenced files. It detects
three conditions that may indicate that a key-sequenced file needs to
Files can be scheduled for automatic reload.
- The number of index levels is too high
- There is too much slack space in the file
- The data blocks in the file are disordered
User disk space
You can specify a disk space quota for the users on your system. When a
user exceeds his quota, Discover performs an action specified by the
system administrator. For example, a message can be logged to the
console, or a report can be run listing files owned by the user.
Discover provides two reports which give details on space usage on a
user by user basis. One report lists the space used, and number of
files owned by a particular set of users. The other report lists all
users showing those who have most exceeded their quota first.
measures initiated automatically
Discover responds automatically to the conditions that it detects.
Corrective action are scheduled via the To Do List. The To Do List is
like a task scheduler.
Each To Do List entry is called a task, and specifies what action is to
be performed, when it is to be performed, and whether the action is
manual or automatic.
Actions which may be specified include:
- Compressing free-space on a disk volume
- Increasing the “maxextents” value for a file
- Reloading key-sequence files
- Moving files to another disk volume
- Backing up files to tape
- Sending an alert message to the Event
Management System, a log file, or a device.
- Running a TACL script
The Discover command interpreter program is used to communicate with
the monitor. It may be run interactively, or in batch mode. The command
interpreter supports commands to generate reports from the information
collected by the monitor. The available reports include:
All of these reports can produce "comma separated values" -- allowing
easy importing into a spreadsheet.
- Disk volumes sorted by growth rate
- Disk volumes sorted by estimated time until full
- Disk volumes sorted by space utilization
- Disk volume summary showing space utilized for
code files, temp files, log files etc.
- Disk volume space usage predictions
- Files sorted by growth rate
- Files sorted by estimated time until full
- File space usage predictions
- User disk space quotas, including current use
Discover allows the system administrator to automate many file
maintenance tasks. However, there are some situations in which full
automation is not possible, or indeed, desirable.
For example, suppose the administrator wishes to clean up old files
that are no longer needed. The files are to be backed up to tape and
then purged from disk. He could identify "old" files as those which
have not been opened for a year (as an example). However, how does he
know which files are safe to purge? An application might require a
certain file only on leap years, purging it would cause problems the
next time it was required.
The administrator should consult the user department responsible for
the files in order to confirm that it is safe to archive them. The end
user may identify certain files that must be retained on disk, and
others which can be purged without being backed up to tape. Armed with
this feedback, the administrator can then process the files
appropriately. Discover worksheets support such a change management
A worksheet is used to track files which the administrator has
identified as candidates for some sort of action. The recommended
action can be signed off by the end user, or an alternative action can
be specified. When agreement is reached, the worksheet is scheduled for
processing on the TODO list. Each action is performed and an optional
audit trail is written to record the outcome. Files which are not
signed off are not processed. They remain in the worksheet until a
decision has been made on what to do with them.
Discover comes with more than ten pre-defined worksheets to handle
common file maintenance tasks, for example:
Files are added to a worksheet either based on conditions detected
during a scan, or by the ADD FILES command.
- Reloading disorganized key sequence files
- Archiving old files
- Increasing MAXEXTENTS for files that are
- Purging corrupt files
- You can add new worksheets to deal with any
maintenance tasks that you need to perform either on a one-off basis,
or on a regular basis.
Worksheets can be processed on demand, or automatically once a day or
on specific days of the week.
Reports can be generated listing the files in a worksheet with various
selection and sorting options.
Discover provides a set of useful disk utilities for use by system
administrators and general users
Checks the health of key
Displays information about
volumes and files
Locates the primary partition
of a partitioned file
Displays information about
The Recycle Bin
The recycle bin allows users to UNDELETE files that were deleted by
The DEL utility is used instead of the TACL or FUP PURGE commands. DEL
deletes the file but keeps a copy in the recycle bin. the UNDEL utility
restores the file from the recycle bin to its original location.
You configure the recycle bin to use a small percentage of the free
space on each disk. If it fills up, the oldest files in the bin are
physically purged to make way for new files. As long as a file has not
been purged to make way for newer files, it can be undeleted.
There are also utilities to display information about the recycle bin,
to empty it, and to repair it.
Worksheets support the BACKUP and ARCHIVE actions. These allow files to
be backed up to tape (and optionally purged). The actions apply to the
files in the worksheet as a group, so that the files are backed up to
the same tape(s). An audit trail is kept which identifies the tape to
which the files were backed up.
Easy to set up
Several features make Discover easy to set up and use:
- Step by step installation procedure
- Simple configuration parameter specification
- Easy to use command interpreter with complete
- No special system requirements
- No SYSGEN required.
PC: Windows 7/8/10