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This chapter contains the following sections:
To run NTDS Administrator:
You use NTDS Administrator to:
For each of these disk services, you can find out the disk number of the virtual disk and the drive letters currently assigned to the partitions on it.
For more information, see NTDS Administrator's online help.
| On the... | Use... |
|---|---|
| OpenVMS Alpha node | The following commands to get information on the disk services that are currently available and the Windows NT computers that are connected to them: |
| Windows NT computer | NTDS Administrator and the Windows NT Event Viewer to find out which disk services the computer is currently connected to. For information on using the Windows NT Event Viewer, see Section 4.1. |
The following examples show how to use the NTDS SHOW SERVER and NTDS SHOW SERVICES commands:
$ NTDS SHOW SERVER
DIGITAL OpenVMS Disk Services for Windows NT
Cluster name: Media
PID of server process: 222000D2
Active disk services: 2
Connections: 1
Standby disk services: 1
If a service is active and a Windows NT computer is connected to it, the Computer connected field contains the name of the computer, otherwise it contains (none).
$ NTDS SHOW SERVICES
DIGITAL OpenVMS Disk Services for Windows NT
Disk services available on this node:
Service name: Music
Status: Active
Computer connected: (none)
Container file: DISK$MEDIA:[NTDS$CONT]MUSIC.NTDS;1
Service name: Sports
Status: Standby
Computer connected: (none)
Container file: DISK$MEDIA:[NTDS$CONT]SPORTS.NTDS;1
Service name: Movies
Status: Active
Computer connected: NTSERVER5
Container file: DISK$MEDIA:[NTDS$CONT]MOVIES.NTDS;1
$ NTDS SHOW SERVICES "Movies" /FULL
DIGITAL OpenVMS Disk Services for Windows NT
Disk services available on this node:
Service name: Movies
Status: Active
Computer connected: NTSERVER5
Container file: DISK$MEDIA:[NTDS$CONT]MOVIES.NTDS;1
Read operations: 14350
Blocks read: 651367
Write operations: 43018
Blocks written: 4200499
$ RUN SYS$SYSTEM:SYSMAN SYSMAN> SET ENVIRONMENT /CLUSTER SYSMAN> SET PROFILE /PRIVILEGES=SYSPRV SYSMAN> DO NTDS SHOW SERVICES "Movies" SYSMAN> EXIT
Service failover is automatic in an OpenVMS Cluster. When the node currently providing a service fails, the service automatically fails over to a node that is configured to provide the standby service.
There may be times when you want to force a service to fail over to a standby, for example, to balance the load across the nodes in your OpenVMS Cluster.
To do this, stop the service on each of the nodes on which it is currently available except for the target node, and then restart it on those nodes.
For example, the Sports service is currently active on node GREEN and has standbys on nodes BLUE and ORANGE. GREEN is heavily loaded, so you decide to fail the service over to ORANGE:
$ RUN SYS$SYSTEM:SYSMAN SYSMAN> SET ENVIRONMENT /NODE=(GREEN,BLUE) SYSMAN> SET PROFILE /PRIVILEGES=(SYSNAM,SYSPRV) SYSMAN> DO NTDS STOP SERVICE "Sports" /OVERRIDE 1 SYSMAN> DO NTDS START SERVICE "Sports" - 2 _SYSMAN> /CONTAINER=DISK$MEDIA:[NTDS$CONT]SPORTS.NTDS SYSMAN> EXIT
To move a connection from one Windows NT computer to another:
The drive letters assigned to the partitions on the virtual disk may be different from those on the original Windows NT computer. To change the drive letters, use Windows NT Disk Administrator.
If you want to share the virtual disk, do so in the normal way, for example, using Windows NT Explorer.
If the Windows NT computer currently connected to a service fails, it is safe to connect another Windows NT computer to the service, provided that you are sure that either:
When the original Windows NT computer restarts it automatically tries to reconnect to the service. If the service happens to fail over from one node in the OpenVMS Cluster to another while it is restarting, it might succeed in reconnecting to the service, stealing the connection back from the other Windows NT computer. If this happens, your data could be corrupted.
You can use Windows NT backup tools to back up and restore the data stored on a virtual disk created by DIGITAL OpenVMS Disk Services for Windows NT.
You can use them to back up or restore either:
You can use OpenVMS backup tools to back up and restore a virtual disk created by DIGITAL OpenVMS Disk Services for Windows NT.
You back up and restore the OpenVMS container file that is used to store the data for the virtual disk.
From OpenVMS, you cannot back up or restore selected Windows NT files on the virtual disk. You must back up and restore the whole of the virtual disk.
If the container file is stored in a Files-11 volume, you must make sure that the back up captures a consistent snapshot of the entire container file at a single instant in time. You must make sure that the container file you are backing up is not being modified during the backup, otherwise your backup will be inconsistent.
To do this, during the backup, take the disk service off line by either:
Disconnecting the Windows NT Computer from the Disk Service
Use NTDS Administrator to disconnect the service before you start the backup, and to reconnect the service when the backup is finished.
This is the recommended method. It produces a backup that contains all the updates written to the Windows NT computer's cache. Disconnecting the Windows NT computer from the service flushes the data from its cache.
When you back up the container file, use the /IGNORE=INTERLOCK qualifier. Because you have not stopped the service, the server software has the container file open so the backup will fail if you do not use this qualifier.
Disconnecting a disk service automatically closes all open files in NTFS partitions on its virtual disk.
Note that you cannot disconnect a disk service if its virtual disk has a non-NTFS partition (for example, a FAT partition) and there are any open files in the partition. In this case, do one of the following:
If the virtual disk has multiple partitions, the failed attempt to disconnect the service might succeed in taking the other partitions off line and making them inaccessible. To get them back on line again, use the Windows NT Disk Administrator to reassign drive letters to them.
Stopping the Disk Service on the OpenVMS Cluster
Use the NTDS STOP SERVICE command with the /OVERRIDE qualifier to stop the service before you start the backup, and the NTDS START SERVICE command to restart it when the backup is finished.
Make sure that you use NTDS STOP SERVICE with /OVERRIDE on every node that can provide the service. Stop the service on the node currently providing the service and on all of its standbys.
This method does not capture unwritten data in the Windows NT computer's cache. It produces a backup that captures the same data as you would find on disk if the Windows NT computer crashed.
This method is not recommended if users are writing data to the virtual disk during the backup.
If the container file is stored in a Spiralog volume, you do not have to take the disk service off line while you back up the container file. You can issue the SPIRALOG SAVE command at any time; it always captures a consistent snapshot of the entire container file at an instant in time, even when users are updating the Windows NT files stored in it.
The SPIRALOG SAVE command does not flush the Windows NT computer's cache, so it captures the same data as you would find on disk if the Windows NT computer crashed.
If you want to capture recent updates written to the Windows NT cache, use NTDS Administrator to disconnect the Windows NT computer from the service before you issue the SPIRALOG SAVE command.
You can reconnect the computer to the service after a few seconds (as soon as the SPIRALOG SAVE /LOG command issues the FLUSHDONE message).
When you do an incremental backup, you back up the changes to the container file, not the whole container file.
Follow these steps to restore data from OpenVMS:
You can restore the container file to the same or a different OpenVMS disk.
If you restore it to the same disk and the same directory, we recommend that you change its name. For example, if you restore SPORTS.NTDS to its original directory, call it SPORTS_RESTORE.NTDS.
Use the NTDS START SERVICE command to start a disk service for the restored container file. For example:
$ SET PROCESS /PRIVILEGE=(SYSNAM,SYSPRV) $ NTDS START SERVICE "Sports_restore" - _$ /CONTAINER=DISK$MEDIA:[NTDS$CONT]SPORTS_RESTORE.NTDS
On the Windows NT computer, use NTDS Administrator to add then connect to the service.
On the Windows NT computer, use NTDS Administrator to disconnect the service.
Use the NTDS STOP SERVICE command to stop the disk service for the restored container file. For example:
$ NTDS STOP SERVICE "Sports_restore"
For example:
$ DELETE DISK$MEDIA:[NTDS$CONT]SPORTS_RESTORE.NTDS;1
This section describes the things you can do to optimize the performance of your disk services.
$ UCX SET CONFIGURATION PROTOCOL TCP /NODELAY_ACK
Do this on all the OpenVMS Alpha nodes that provide disk services.
To do this, make sure that the IP subnet associated with the fastest card is at the top of the subnet list displayed by the NTDS Administrator's Communication Settings screen (Figure 2-2). If necessary, use the Up and Down buttons to change the order of the entries in the list.
For example, if the computer has an FDDI card and an Ethernet card, make sure the IP subnet associated with the FDDI card is listed first.
The performance of a disk service is sensitive to the amount of memory available to the computer connected to the service and the workstations that access shares on it (the computers in tiers 2 and 3 in Figure 1-1). More memory means a bigger cache, which means fewer I/Os are issued to disk.
Use NTDS SHOW SERVICES with /FULL to check the ratio of reads and writes to disk. If it shows a high proportion of reads, it probably means that the Windows NT computer's cache is not big enough. Increase the size of its cache to try to get this ratio as near to zero as possible.
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