Data Storage and Management |
Systems with a few stand-alone drives and a single Removable
There are many drives and robotic libraries available, and not all of them can be supported. See the Microsoft Windows 2000 Hardware Compatibility List (HCL) link on the Web Resources page at http://windows.microsoft.com/windows2000/reskit/webresources.
Each of the supported robotic libraries has its own configuration method and options. In order for them to work correctly with Removable Storage you must configure your robotic libraries with certain settings of these options. Please consult the HCL for the proper configuration settings for all supported drives and robotic libraries.
Under normal circumstances, Removable
Some applications use their own format or labeling scheme. In order for Removable Storage to correctly process OMIDs on the sides written by these applications, it needs a special dynamic-link library (DLL) that can read the label and determine the OMID. Such a DLL is called a media label library (MLL), and client applications that use them must install them.
Most applications draw available media from the free pool. Placing media in the free pool is also called "preparing" the media, and must be done either by a Removable
To prepare a tape, for example, in the Removable Storage snap-in, right-click the media in the details pane, and then click Prepare.
A Removable Storage operator request is a request for an administrator to perform a task. Operator requests can be issued by Removable Storage or by Removable Storage client applications. Removable Storage generates operator requests in the following situations:
Operator requests are displayed in the Removable Storage snap-in. Administrators can satisfy or cancel operator requests. After satisfying an operator request, the administrator must acknowledge the request in the Removable Storage snap-in. When an administrator cancels an operator request, Removable Storage notifies the application that generated the request. Removable Storage saves operator requests for less than one hour after they have been satisfied or canceled.
Removable Storage provides security for itself, media pools, and libraries. It contains an access control list (ACL) that controls who can connect to the service and who can work with operator requests. To edit this ACL, right-click the root node in the Removable Storage snap-in. Each library has an ACL that governs who can perform specific tasks, and each pool also contains an ACL. Table 2.6 describes what permissions are required for specific snap-in operations.
Table 2.6 Permissions Required For Removable Storage Snap-in Operations
Function | Media Pool | Library | Service | ||||||
---|---|---|---|---|---|---|---|---|---|
Use | Modify | Control | Use | Modify | Control | Use | Modify | Control | |
Connect to the service | X | ||||||||
Create media pools | X | ||||||||
Delete media pools | X | ||||||||
Dismount media | X | X | |||||||
Mount media | X | X | |||||||
Move media from pool to pool | X | ||||||||
Open the library door | X | ||||||||
Delete a library | X | ||||||||
Dismount a drive | X | ||||||||
Eject media | X | ||||||||
Insert media | X | ||||||||
Inventory a library | X | ||||||||
Cancel an operator request | X | ||||||||
Satisfy an operator request | X | ||||||||
Clean a drive | X | ||||||||
Insert/eject a cleaner | X |
Removable Storage is configured in Windows 2000 to start automatically when you start your computer. It is possible to change the service to be manually started, but this is highly discouraged. Disabling the service breaks several applications that are included with Windows 2000, such as Backup and Remote Storage.
As with other Windows 2000 services, Removable Storage can be stopped, started, and restarted by means of the service control manager.
Removable Storage performs several tasks when it starts. During some of these tasks Removable Storage is unavailable to administrators and client applications. At other times during startup it can accept requests; however, execution might be delayed while Removable Storage completes this initialization. The following steps outline the process performed by Removable Storage during startup:
Note
It is important to note that the process is the same whether Removable Storage is starting after a system start or simply restarted while the system is running.
Because Removable Storage manages removable media devices, it relies on Plug and Play to tell it which devices are attached to a system, but Removable Storage must match drives with robotic libraries. If Plug and Play indicates that a robotic library is attached to a system, Removable Storage must go through the list of drives that are also attached and detect which ones are actually inside the robotic library and which are stand-alone drive libraries. If certain rules are followed, Removable Storage can do this mapping entirely on its own. If these rules cannot be followed, you must manually map drives to robotic libraries.
Removable Storage auto-configures robotic libraries if the following are true:
Because not all library hardware units and system configurations support the Removable Storage auto-configuration feature, Removable Storage provides a method for manually configuring library hardware units. However, only use this method when it is necessary, because Removable Storage cannot detect manually configured changes. In general, manually configure Removable Storage only when it detects a robotic library that it cannot configure. After it is set for manual configuration, a changer does not participate in auto-configuration even if its configuration is changed.
In most cases, Removable Storage starts auto-configuration after hardware is installed, moved, or removed. This happens automatically when you restart after adding the device. For changers that cannot be auto-configured, Removable Storage adds incomplete registry entries and generates an operator request to manually configure such changers. The following procedure can be used to manually configure Removable Storage.
To manually configure Removable Storage
You must complete all of the following steps to manually configure Removable Storage:
Caution
Do not use a registry editor to edit the registry directly unless you have no alternative. The registry editors bypass the standard safeguards provided by administrative tools. These safeguards prevent you from entering conflicting settings or settings that are likely to degrade performance or damage your system. Editing the registry directly can have serious, unexpected consequences that can prevent the system from starting and require that you reinstall Windows 2000. To configure or customize Windows 2000, use the programs in Control Panel or Microsoft Management Console (MMC) whenever possible.
If Removable Storage does not generate any error messages, the manual configuration was successful, and you have completed the manual configuration process.
Removable Storage stores its catalog of media in a database on disk. While Removable Storage can recover some of the information by inventorying the attached libraries, all of the application-oriented information might be lost if the database is lost. For this reason, the Removable Storage database must be backed up regularly. For more information about backing up the Removable Storage database, see "Backup" in this book.
The default location for the Removable Storage database is
If you decide to move the database or if you do not use Backup, you are responsible for ensuring that you get a consistent database when you do a backup.
Important
The backup application that you use is responsible for backing up Removable Storage. If you do not use Backup, which is part of Windows 2000, and you do use Removable Storage, verify that the backup application backs up Removable Storage.
The database must be internally consistent to produce a backup that can be restored successfully. There are two ways of doing this: shutting down Removable Storage and exporting the database. The latter is what Backup does if you have not changed the location of the Removable Storage database and you select ntmsdata. If you can shut down Removable Storage while backing up the database, your backup operation can simply make copies of the database files themselves. If shutting down the service is not an option (for example, because a Removable Storage–aware application must remain running), you must provide a way for Removable Storage to export a consistent copy of the database for backup. You can also create a small Removable Storage–aware application that calls the ExportNtmsDatabase API. For more information about this API and about writing Removable Storage–aware applications, see the Microsoft Platform Software Development Kit (SDK) link on the Web Resources page at http://windows.microsoft.com/windows2000/reskit/webresources.
The administrator must always know the location of the most recent Removable Storage database backup. To help identify the backup during disaster recovery, the administrator needs to record and maintain the medium display name and the on-media identifier in a safe place.
You might need this information to help the backup application identify the media from which to restore the database. You can get the display name from the property page for the medium, and the on-media identifier from the property page on the property sheet for the medium side.
Note
The information in this section assumes that there has been no change to the system configuration that affects Removable Storage since the backup was made.
To allow the recovery application to access media, it must be mounted in a drive. If you are going to restore the database using Backup, then Removable Storage must be running and you can use Removable Storage to mount the media, but without the full database you'll have to get Removable Storage running with enough of a database to mount the database backup tape for Backup. To do this, delete any files that might be in ntmsdata and start Removable Storage. Removable Storage then inventories each of the libraries attached to the system.
Tip
For large libraries, this might take hours. To minimize the time for this process, perform standard backups often.
Tapes made with Backup show up in the import pool. Start Backup and have it move these tapes to its own application pool. Select the ntmsdata directory and start a restore process. Backup will store the database files and set Removable Storage to run on the recovered database after the next service restart.
If you are not using Backup, you need to use other means to mount the media, restore the files, and recover the database. Most libraries have doors or front panels that you can use to mount media manually. Next, copy or restore the database files to disk. If Removable Storage is not running, you can copy the database files to a directory that holds the Removable Storage database (
The recovered database might not be synchronized with the state of media when the database was lost. Table 2.7 describes some reasons why the Removable Storage database might not be synchronized and how Removable
Table 2.7 Synchronizing Restored Database Files
Problem | Solution |
---|---|
A medium is deallocated by an application after the backup but before the disaster and remains in the application media pool. Removable Storage recognizes this medium as allocated and puts it in the application media pool. | The application can deallocate this medium again. |
A medium is allocated by an application after the backup but before the disaster. Removable Storage puts the medium in the import media pool. | The application can allocate this medium directly out of the import pool. |
Note
An application can recover the Removable Storage database when it has been lost,there is no backup copy, and the application has not lost the database that refers to the lost Removable Storage database. This process requires significant knowledge on the part of the administrator of the application.
The Removable Storage snap-in allows you to perform several tasks. The snap-in can be found beneath the storage node in the Computer Management snap-in. It can also be started directly from the command line, by running Ntmsmgr.msc.
Removable Storage uses a library's IE port, if it has one, for inserting and ejecting media, or it uses the door. Selecting an insert task on a library with a door but no IE port results in the same behavior as if you selected a door access.
When using a door access to enter or remove media, make sure that you consult the property page for the library and the document for the changer to determine the proper slot numbers. Most changers label each slot clearly, but some do not.
Caution
If during a door access you exchange media in libraries without bar codes, you need to run a full inventory after completing the door access. The change is not detected by a fast inventory and an identity mismatch occurs the next time media in the slot is mounted.
Tables 2.8, 2.9, and 2.10 show the results of moving CD media, tape media, and optical/rewritable media among media pools.
Note
Because CD media are read-only, Removable Storage does not allow each medium to be placed in the free pool.
CD media appear in the unrecognized pool only if they are formatted with a file system that Windows 2000 does not recognize.
Table 2.8 Moving CD Media Among Media Pools
From/To | Import Pool | Unrecognized Pool | Application Pool |
---|---|---|---|
Import | Not Allowed | OK | |
Unrecognized | Not Allowed | Not Allowed | |
Application | OK | Not allowed |
Table 2.9 Moving Tape Media Among Media Pools
From/To | Free Pool | Import Pool | Unrecognized Pool | Application Pool |
---|---|---|---|---|
Free | Not Allowed | Not Allowed | Retains Free Label until application writes new label. | |
Import | Write Free Label | Not Allowed | Not Allowed | |
Unrecognized | Write Free Label | Not Allowed | Not Allowed | |
Application | Write Free Label | Not Allowed | Not Allowed | Retains current Label |
Table 2.10 Moving Optical/Rewritable Media Among Media Pools
From/To |
Free Pool |
Import Pool |
Unrecognized Pool | Application Pool |
---|---|---|---|---|
Free | Not Allowed | Not Allowed | Retains Free Label until application writes new label. | |
Import | Write Free Label | Not Allowed | Retains label already on media. | |
Unrecognized | Write Free Label | Not Allowed | Not Allowed | |
Application | Write Free Label | Not Allowed | Not Allowed | Retains current Label. Both sides are moved. |
There are two types of inventories, fast and full. You can set which is to be used as the default inventory method in the Library property page in the Removable Storage snap-in.
A fast inventory only checks for slot state changes between full and empty. If the Removable Storage database indicates that a slot has a cartridge in it, but the fast inventory shows that it no longer has a cartridge, Removable Storage marks the cartridge that was in the slot as offline. If a slot was empty and is now full, Removable Storage identifies the cartridge in the slot. Slots that remain full are assumed to contain the same cartridge. Full inventory actually identifies each medium. This can take a while, unless the media has bar code labels. A full inventory of bar code–labeled media only reads the bar codes. Full inventories of media that are not bar coded read the on-media identifier on each medium in the library.
Some drives, especially tape drives, require periodic cleaning. Usually there is a light on the front of the drive that indicates that a drive is dirty, and in this state most I/O operations fail. Under most circumstances a drive detects that it is dirty while a Removable Storage client application is running. How the client application handles this situation is typically described in the documentation for that application, but for some changers Removable Storage can automatically clean the drive for you after the application is finished using the drive.
In the Removable Storage model of device maintenance, each library unit can contain one cleaner cartridge. There is a wizard available through the snap-in, which you can use to insert a cleaning cartridge into each library that supports automatic cleaning.
Removable Storage maintains a usage count for each cleaner cartridge. When a cleaner reaches its maximum usage count, Removable Storage generates an operator request. If the administrator ejects a cleaner cartridge before it has reached its maximum usage count, Removable Storage displays the usage count information.
Caution
Problems occur if Removable Storage attempts to identify a cleaning cartridge as a regular medium. Most drives treat cleaning cartridges differently from regular media, and this different behavior can result in Removable Storage error messages that might appear as if Removable Storage or the library is malfunctioning. Never start Removable Storage for the first time with a cleaning cartridge in the library, or attach a new library with a cleaning cartridge inside. In both these cases Removable Storage performs a full inventory of the library, which includes trying to identify each cartridge. In addition, never insert a cleaning cartridge using the same mechanism used for ordinary media. If there is any doubt about the Removable Storage database's consistency, please remove the cleaning cartridges from the attached libraries. These problems might appear if the database becomes inconsistent or is restored from an old backup.
You can use the property page about the work queue item to control how long completed and failed work queue items are retained. If you are having problems you might set the work queue to retain failed items so that you can investigate. The property page for each failed item shows the reason that it failed.
On startup you might see a number of canceled work queue items. When Removable Storage is shut down there might be work queue items still queued. These are canceled the next time Removable Storage starts up.
Use the property page on the root node of the Removable Storage snap-in to set a method to receive notification of outstanding operator requests. The two available methods are Windows 2000 Messenger Service and a system tray icon. When the messenger service is selected, an application message appears whenever there is an operator request. Make sure that the Messenger Service is running if this option is selected, and then start the Removable Storage snap-in to view the operator request queue and determine what Removable Storage is asking you to do.
If the system tray method is selected, a system tray icon appears whenever there is an outstanding operator request. Clicking on the system tray icon displays a snap-in of operator requests, making it easier to mark them refused or complete. All operator requests must be completed or refused.
The property page of the operator request node in the Removable Storage snap-in lets you set how long to retain completed and failed (including canceled) operator requests. It also provides buttons that can be used to process deleted, completed, and failed operator requests immediately. The Default button deletes all requests specified by the controls on the properties sheet, while the Delete all now button deletes all completed and failed requests.
A library is online while it is operating and connected to the computer that is running Removable Storage. A library is not present if it is not operating or if it is disconnected from the computer. Both robotic and stand-alone libraries can be either online or not present. If a library is removed, the administrator must manually delete the library from Removable Storage. Removable Storage does not automatically delete libraries to avoid deleting information that might still be valuable if the library was disconnected inadvertently or temporarily.
Drives in offline libraries are offline, but media in offline libraries are considered online since they reside in a library. Offline media physical locations, then, are different from offline libraries.
You can create command scripts to perform routine or automated activities using the Removable Storage command-line program Rsm.exe. You can use this program to have Removable Storage perform a number of activities, such as ejecting tapes, creating medial pools and so on.
Problems with Removable Storage can be caused by hardware or software. The information required to help you resolve either type of problem is contained in the following paragraphs.
If you are having problems with Removable Storage correctly configuring your devices, please consult the HCL to make sure your device is supported. If it is, make sure you have configured the device according to the guidelines listed for your device on the HCL. Many changers support many operational configurations, while Removable Storage requires certain settings of these configurations.
Make sure that the hardware is configured correctly. If the device is attached to the host by means of a SCSI bus, ensure that the bus is configured correctly, with no SCSI ID collisions, with proper termination and in accordance with all cable length and SCSI controller parameters, and so on. IDE devices need to be properly configured as master or slave devices and the like.
If all the hardware is configured properly, make sure that Windows 2000 has found the devices and loaded the drivers for them. Make sure you should see your changer under Media Changers in the Device Manager, and any drives under Disk drives or Tape drives. If a driver is loaded, check the system Event Log to see if the driver encountered an error while initializing the device.
If all the devices are working properly, but Removable Storage is still unable to configure them automatically, try manually configuring the devices.
If you are getting failed work queue items, the property sheet gives a reason for the failure, which can help you diagnose the problem.
If your library is configured correctly but begins malfunctioning, the first place to look for the cause is the system log. Look for Removable Storage messages, but also look for change, drive, and controller error messages. If these devices are experiencing errors, take appropriate actions to clear the errors, such as power cycling or resetting the device.
Operations can begin failing if the system runs low on system resources, such as memory and disk space. You can determine if this is the case by checking the system Event Log.
If the devices and the rest of the system appear to be operating normally, stopping and restarting Removable Storage might clear problems.
If media that are associated with client applications known to Removable Storage are always placed in the unrecognized pool when inserted, or mount requests fail because of an OMID mismatch, the MLL might be missing or installed incorrectly. Information about MLLs is contained in the registry entry HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control
\NTMS\OMID\Tape.
Typically, the directory