HP OpenVMS Systems Documentation
OpenVMS System Manager's Manual
9.13.2 Using Mount Verification
The following sections explain how to perform these tasks:
126.96.36.199 Enabling Mount Verification
Mount verification is enabled by default when you mount a disk or tape. To disable mount verification, you must specify /NOMOUNT_VERIFICATION when you mount a disk or tape.
Note that this feature applies to standard mounted tapes, foreign
mounted tapes, and Files-11 disks.
You can control the amount of time (in seconds) that is allowed for a mount verification to complete before it is automatically canceled. The MVTIMEOUT system parameter for disks and the TAPE_MVTIMEOUT system parameter for tapes define the time (in seconds) that is allowed for a pending mount verification to complete before it is automatically canceled.
The default time limit for tapes is 600 seconds (10 minutes); for disks, it is 3600 seconds (1 hour). (Refer to the OpenVMS System Management Utilities Reference Manual for more information about system parameters.)
Always set either parameter to a reasonable value for the typical
operations at your site. Note that resetting the value of the parameter
does not affect a mount verification that is currently in progress.
When a mounted disk or tape volume goes off line while mount verification is enabled, you can try to recover, or you can terminate the mount request. The following options are available:
If you successfully put the device back on line, the mount verification software that polls the disk or tape drive begins verification in the following sequence of steps:
188.8.131.52 Recovering from Write-Lock Errors
Devices become write-locked when a hardware or user error occurs while a disk or a tape volume is mounted for a write operation. For example, if a disk is write-locked or a tape is missing a write ring, the hardware generates an error. As soon as the software discovers that the disk or tape is write-locked (for example, when an I/O operation fails with a write-lock error), mount verification begins.
OPCOM issues a message in the following format to the operators enabled for DISKS and DEVICES or TAPES and DEVICES, announcing the unavailability of the disk or tape:
You can either recover the operation or terminate mount verification. Your options include the following ones:
Once the mount verification software determines that the volume is in a
write-enabled state, I/O operations to the tape or disk resume with no
You can cancel a mount verification request in one of the following ways:
The following section describes the first method, using the DISMOUNT command, in more detail. See Section 9.14.2 for details about using the last method, IPC, to cancel mount verification.
To dismount a volume:
9.14 Using Interrupt Priority Level C (IPC)
IPC is a special program that issues a software interrupt to gain the attention of the console terminal. You can use IPC commands to adjust quorum in an OpenVMS cluster, to cancel mount verification, or to enter the debugger. (The debugger in this case refers to the system-level debugger, XDELTA.)
The IPC program converts lowercase letters to uppercase, issues the terminal bell character whenever it receives illegal characters (such as most control characters), compresses multiple spaces, and ignores leading spaces.
9.14.1 Recalculating Quorum
Although IPC Q commands recalculate quorum in an OpenVMS Cluster, do not use these commands. Instead, use either of the following to recalculate cluster quorums:
9.14.2 Canceling Mount Verification
To cancel mount verification using IPC, enter the following command from the console terminal in response to the IPC> prompt:
This command cancels any pending mount verification on the device specified. (A warning is given if no mount verification was in progress for that device.) For example:
When a pending mount verification is canceled, OPCOM prints a message in the following format:
After you successfully cancel a pending mount verification using this technique, you must dismount and then remount the volume before you can access it again.
On VAX systems, you might enter the following commands:
On Alpha systems, you might enter the following commands:
In both examples, device DUA0: is off line, but you are unable to spin the disk back up. No other drive is available on the controller, so you cannot switch the unit select plugs of the two drives.
Do not enter a DISMOUNT command for the disk because it was mounted as
a private volume, and you do not have access to it. The
%SYSTEM-I-MOUNTVER message also appears because this is the console
To use the XDELTA debugger, enter the following commands from the console terminal:
You are now in the debugger. The X command transfers control to the debugging tool XDELTA (provided it was loaded with the system by setting the appropriate value in the boot file). If XDELTA has not been loaded, the prompt IPC> is reissued. For example:
To exit from the debugger, press Ctrl/Z:
For information about the XDelta debugger, refer to the OpenVMS Delta/XDelta Debugger Manual.
To test the blocks on a volume, ANALYZE/MEDIA performs the following tasks:
If the data does not compare exactly, a block cannot reliably store data.
When the Bad Block Locator utility locates a bad block, it records the address of the block. Consecutive bad blocks are recorded as single entries for non-last-track devices. After it finishes testing the disk, BAD writes the addresses of the bad blocks into a file called the detected bad block file (DBBF).
To use BAD, perform the following steps:
Refer to online help or to the archived manual OpenVMS Bad Block Locator Utility Manual for details on using the Bad Block Locator utility.
|Using Extended File Specifications features||Section 10.1.1|
|Controlling access to ODS-5 volumes||Section 10.2|
|Getting file information||Section 10.4|
|Protecting disk files||Section 10.5.3|
|Protecting disk directories||Section 10.5.4|
|Protecting magnetic tape files||Section 10.5.5|
|Accessing disk files||Section 10.6|
|Accessing tape files||Section 10.7|
|Copying and transferring files||Section 10.8|
This chapter explains the following concepts:
|Extended File Specifications features||Section 10.1|
|DCL commands with files||Section 10.3|
|File protection||Section 10.5.1|
|Tape file names||Section 10.7.1|
Beginning with OpenVMS Version 7.2, Extended File Specifications remove many of the file-naming restrictions previously imposed by OpenVMS and offer full support for the following file-naming features. Together, these features provide consistent file handling across both OpenVMS and Windows NT systems in a Compaq Advanced Server for OpenVMS environment.
|New on-disk structure||Extended File Specifications support the latest volume On-Disk Structure (ODS): Level 5 (ODS-5). This volume structure provides the basis for creating and storing files with extended file names.|
|Additional character set support||A broader set of characters is available for naming files on OpenVMS. Extended File Specifications offers support for file names that use the 8-bit ISO Latin-1 character and 16-bit Unicode (UCS-2) character sets.|
|Extended file naming||File names can now exceed the traditional 39.39 character limit up to a maximum of 236 bytes.|
|Case preservation||Extended File Specifications preserve the case of file specifications created with ODS-5 attributes. However, the system still performs case-insensitive string matching.|
|Deep directory levels||To support deep directory levels, the length of directory specifications has been extended to a maximum of 512 characters.|
For more information about each feature, refer to OpenVMS Guide to Extended File Specifications.
10.1.1 Using Extended File Specifications
Beginning with OpenVMS Version 7.2, RMS allows you to use directory levels deeper than 8 as well as the new RMS API extensions on both ODS-2 and ODS-5 volumes by default. However, you can create extended file names only on an ODS-5 volume. Section 9.3.3 and Section 184.108.40.206, respectively, explain how to create a new ODS-5 volume and how to convert an ODS-2 volume to an ODS-5 volume.
Once you change a volume to ODS-5, your programs can create and read extended file names. However, by default, DCL (as well as some applications) does not accept all extended names.1 DCL also capitalizes any lowercase file names that users enter at the command line prompt.2
For DCL to accept all extended file names, you must enable the Extended File Specifications file name parsing feature. On OpenVMS Alpha systems, you can instruct DCL to accept ODS-5 file names on a per-process basis by entering the following command:
$ SET PROCESS/PARSE_STYLE=EXTENDED
After you enter the command, DCL accepts a file name similar to the following:
$ CREATE MY^[FILE
For more details on setting parse styles, refer to the OpenVMS DCL Dictionary. The OpenVMS Record Management Services Reference Manual contains additional information about RMS default Extended File Specifications features.
1 Even with the TRADITIONAL parse style, DCL allows some ODS-5 file names; for example, DCL accepts x.x.x.
2 Some applications also use DCL internally to read file names that users type after an application prompt.