|
HP OpenVMS System Manager's Manual, Volume 1:... |
Using BACKUP |
|
|
| |
Preparing to Back Up User Disks
HP recommends that you back up your disks with no
interactive users logged in and with no applications running. This
is because if BACKUP encounters an open file during a save operation,
it issues an error message and does not copy
the file. Also, because of the way BACKUP scans directories, any activity
in a directory (such as creating or deleting files) can cause files
to be excluded from the backup.
 | The first time you back up a disk, you must perform
an image backup using the BACKUP/IMAGE/RECORD command before you
perform regular incremental backups. The image backup saves a copy
of the entire disk and marks each file as being saved. Subsequent incremental
backups assume that an image backup has been performed; only new
or modified files are saved. If an image backup is not performed first, the incremental backups save more files than might be necessary to ensure that an incremental restore operation will be successful. |
However, if the file is accessed for writing from a remote node when BACKUP finishes reading the file, no message is displayed because BACKUP cannot detect the access.
If a file with the specified version already exists, BACKUP reports the following error message:
RMS-E-FEX, file already exists, not supersededHow to Perform This Task
If several users are on your system, notify them that a disk backup is about to take place. If you have the OPER privilege, you can notify users with the REPLY/ALL command, as follows:
When you enter this command, each interactive terminal on the system displays the following message:$REPLY/ALL "System Backup About to Begin -- Open Files Will Not Be Backed Up"
Reply received on MYNODE from user SYSTEM at VTA28: 23:35:11 System Backup About to Begin -- Open Files Will Not Be Backed Up
Performing
Image Backups to Tape
As described in
Understanding Types of Backups, an image backup of
a disk provides you with an exact logical copy of all the files
on the disk. You should perform image backups with no interactive
users on the system because of open file considerations (described
in
Preparing to Back Up User Disks). Also,
system performance can be affected during the backup process, so
it is best to schedule the backup during the least busy times for
your system. You can optimize the speed of the backup procedure
by ensuring that certain process and system parameters are set properly
(as described in
Setting Software Parameters for Efficient Backups).
To perform an image backup, use the BACKUP command in the following format:BACKUP/IMAGE [/RECORD] input-device output-specifier [/LABEL=label] [/REWIND]
The /IMAGE qualifier identifies the backup operation as an image backup. The /RECORD qualifier is optional and records the current date and time in the file header record of each file that is backed up. You must use the /RECORD qualifier if you are planning to perform future incremental backups. Specify the name of the disk you are backing up as the input-device; do not specify individual files. The /REWIND qualifier is optional depending on whether you want to initialize the tape. The /LABEL qualifier identifies the label of the tape.
In this example, the individual commands perform the following actions:$INITIALIZE MKB100: WKLY[1]$MOUNT DKA100: DISK$1[2]%MOUNT-I-MOUNTED, DISK$1 mounted on _DKA100:$BACKUP/IMAGE/RECORD/VERIFY_From:DKA100:_To:MKB100:FULL02.SAV/LABEL=WKLY[3]%BACKUP-I-STARTVERIFY, starting verification pass
In this example, the individual commands perform the following actions:$ALLOCATE MUA0:,MUA1:,MUA2:[1]%DCL-I-ALLOC, MUA0: allocated%DCL-I-ALLOC, MUA1: allocated%DCL-I-ALLOC, MUA2: allocated$BACKUP/IMAGE/RECORD/NOASSIST/RELEASE_TAPE_From:DKA100:_To:MUA0:FULL02.SAV,MUA1,MUA2/LABEL=MNTH[2]%MOUNT-I-MOUNTED, MNTH mounted on _MUA0:%BACKUP-I-RESUME, resuming operation on volume 2%MOUNT-I-MOUNTED, MNTH02 mounted on _MUA1:%BACKUP-I-RESUME, resuming operation on volume 3%MOUNT-I-MOUNTED, MNTH03 mounted on _MUA2:$
Performing Image Backups to Disk
As described in
Understanding Types of Backups, an image backup of a disk provides you with an exact logical
copy of all the files on the disk. You should perform image backups
with no interactive users on the system because of open file considerations
(described in
Preparing to Back Up User Disks).
Also, system performance can be affected during the backup process,
so it is best to schedule the backup during the least busy times
for your system. You can optimize the speed of the backup procedure
by ensuring that certain process and system parameters are set properly
(as described in
Setting Software Parameters for Efficient Backups).
To perform an image backup to a disk, use the BACKUP command in the following format: BACKUP/IMAGE/RECORD input-device output-specifier/SAVE_SET
The /IMAGE qualifier identifies the backup operation as an image backup. The /RECORD qualifier records the current date and time in the file header record of each file that is backed up. This information is essential for future incremental backups. The /SAVE_SET qualifier indicates that you are creating a save set on a disk.
$MOUNT DUA1: USER1%MOUNT-I-MOUNTED, USER1 mounted on _DUA1:$MOUNT DUA2: USER2%MOUNT-I-MOUNTED, USER2 mounted on _DUA2:$BACKUP/IMAGE/RECORD_From:DUA1:_To:DUA2:[USER.BACKUPS]USER1.SAV/SAVE_SET
$BACKUP/IMAGE/RECORD_From:DUA0:_To:DUB24:[USER.BACKUPS]USER1.SAV,DUB25/SAVE_SET
Performing Incremental Backups to Tape
As described in
Understanding Types of Backups, an incremental backup of a disk provides you with an exact
copy of only those files that have been created or modified since
the last image or incremental backup in which the /RECORD qualifier
was used.
To perform an incremental backup to tape, perform the following steps:
The date of the last /RECORD backup is indicated in the Backup field of the display. In this example, a /RECORD backup was performed on 30-APR-2000 20:20:57.37.$DIRECTORY/FULL LOGIN.COMDirectory WORK204:[HIGGINS] LOGIN.COM;31 File ID: (23788,1,0) Size: 7/9 Owner: [ACC,HIGGINS] Created: 30-APR-2000 14:37:33.98 Revised: 30-APR-2000 14:37:34.44 (1) Expires: <None specified> Backup: 30-APR-2000 20:20:57.37 File organization: Sequential File attributes: Allocation: 9, Extend: 0, Global buffer count: 0, No version limit Record format: Variable length, maximum 94 bytes Record attributes: Carriage return carriage control RMS attributes: None Journaling enabled: None File protection: System:RWED, Owner:RWED, Group:RE, World: Access Cntrl List: None Total of 1 file, 7/9 blocks.
| If you used the /IGNORE=INTERLOCK qualifier to back up open files during your last image backup or incremental backup in which the /RECORD qualifier was used, see /IGNORE Qualifier. If the files remain open, they will not be included in the incremental backup because their backup date fields are not as recent as the last image backup or incremental backup in which the /RECORD qualifier was used. |
The following command is an example of an incremental backup in which BACKUP saves all files on DRA1: that were modified since the previous BACKUP/RECORD command and stores them in a save set named 20APR2000.SAV:
The /LABEL qualifier identifies the volume label of the tape. Also, because BACKUP is performing an incremental rather than an image backup, it is necessary to explicitly use the notation DRA1:[000000...] to specify all the files on DRA1. The /SINCE=BACKUP qualifier saves all files created or modified since the last /RECORD backup. The /RELEASE_TAPE qualifier dismounts and unloads an output tape device after BACKUP writes the save set and before it performs the action of the /RECORD command.$BACKUP/RECORD/SINCE=BACKUP/RELEASE_TAPEFrom:DRA1:[000000...]To:MIA0:20APR2000.SAV/LABEL=20JUNE
Performing Incremental Backups to Disk
As described in
Understanding Types of Backups, an incremental backup of a disk provides you with an exact
copy of only those files that have been created or modified since
the last image or incremental backup in which the /RECORD qualifier
was used.
To make an incremental backup to disk, perform the following steps:
The date of the last /RECORD backup is indicated in the Backup field of the display. In this example, a /RECORD backup was performed on 30-APR-2000 20:20:57.37.$DIRECTORY/FULL LOGIN.COMDirectory WORK204:[HIGGINS] LOGIN.COM;31 File ID: (23788,1,0) Size: 7/9 Owner: [ACC,HIGGINS] Created: 30-APR-2000 14:37:33.98 Revised: 30-APR-2000 14:37:34.44 (1) Expires: <None specified> Backup: 30-APR-2000 20:20:57.37 File organization: Sequential File attributes: Allocation: 9, Extend: 0, Global buffer count: 0, No version limit Record format: Variable length, maximum 94 bytes Record attributes: Carriage return carriage control RMS attributes: None Journaling enabled: None File protection: System:RWED, Owner:RWED, Group:RE, World: Access Cntrl List: None Total of 1 file, 7/9 blocks. $
| If you used the /IGNORE=INTERLOCK qualifier to back up open files during your last image backup or incremental backup in which the /RECORD qualifier was used, see /IGNORE Qualifier. If the files remain open, they will not be included in the incremental backup because their backup date fields are not as recent as the last image backup or incremental backup in which the /RECORD qualifier was used. |
$MOUNT DUA55: DISK1%MOUNT-I-MOUNTED, DISK1 mounted on _DUA55:$MOUNT/FOREIGN DJC12:%MOUNT-I-MOUNTED, DISK2 mounted on _DJC12:$BACKUP/RECORD/SINCE=BACKUP_From:DUA55:[000000...]_To:DJC12:USER1.SAV/SAVE_SET
$MOUNT DUA0: USER1%MOUNT-I-MOUNTED, USER1 mounted on _DUA0:$MOUNT/FOREIGN DUB24:%MOUNT-I-MOUNTED, DISK2 mounted on _DUB24:$MOUNT/FOREIGN DUB25:%MOUNT-I-MOUNTED, DISK3 mounted on _DUB25:$BACKUP/RECORD/SINCE=BACKUP_From:DUA0:[000000...]_To:DUB24:USER1.SAV,DUB25/SAVE_SET
Performing Incremental Backups Using PATHWORKS
for OpenVMS Servers
An incompatibility between the operating procedures of the
PATHWORKS for OpenVMS Macintosh server and OpenVMS incremental backup
operations can cause BACKUP to save entire disks or directory structures,
including subdirectories and files.
BACKUP can detect whether a directory file has been modified since the date indicated by the Backup Date field in the file header. If a directory file has been modified, all subdirectories and files of that directory are saved for possible later restore operations.
Updating the modification date of directory files is unusual for OpenVMS systems. However, it can happen if, for example, you rename a directory file from one location to another. In contrast, the PATHWORKS Macintosh server maintains the modification date of directory files for Macintosh users; that is, it updates the modification date for each directory change, file creation, and file deletion.
Thus, an incremental backup of a disk where PATHWORKS is used to serve files to Macintosh users may result in saving the entire disk or entire directories (including their subdirectories and files) instead of just the user files that were created or modified since the last incremental backup operation.
You can avoid saving files unnecessarily in either of the following ways:
In this example, the first BACKUP command performs the dummy backup operation, and the second command performs the actual incremental backup. The first command updates the Backup Date field for all the directory files. Specifying the null output device NLA0:[000000...] causes a save set file not to be written. Because no file information needs to be retained from this operation, the /NOCRC and /GROUP_SIZE=0 qualifiers are specified to avoid CRC and XOR block calculation.$BACKUP/RECORD/IGNORE=(INTERLOCK) -_$disk:[000000...]*.DIR;* -_$NLA0:DUMMY.BCK/SAVE/NOCRC/GROUP_SIZE=0$$BACKUP/VERIFY/FAST/RECORD/IGNORE=(INTERLOCK) -_$/NOASSIST/COMMENT="Incremental backup of DISK:" -_$disk:[000000...]*.*;*/SINCE=BACKUP -_$tape:incr.bck/LABEL=incr/SAVE
Backing Up Your Workstation Disk
On a standalone workstation, you are probably responsible
for backing up files on your user disks.
Using a Command Procedure for Nightly Image Backups,
Using a Command Procedure for Nightly Incremental Backups, and
Using an Interactive Command Procedure for Backups contain command procedures for making image,
incremental, and interactive backups of user disks on your workstation.
HP also provides two template command procedures in the SYS$EXAMPLES directory for you to use in designing BACKUP command procedures. These command procedures are called BACKUSER.COM and RESTUSER.COM.
If you are not familiar with using command procedures, refer to the OpenVMS User's Manual .
Using a Command Procedure for Nightly Image
Backups
The following command procedure performs nightly image backups,
backing up all the files on disk DUA2: to a tape in MUA0. The files
are copied to a magnetic tape save set named FULL_BACKUP.SAV. This
procedure is particularly useful for backing up files on a MicroVAX
system or workstation.
To use the command procedure, perform the following steps:
$!
$! Resubmit this procedure --
$ SUBMIT/AFTER="TOMORROW+2:0" SYS$MANAGER:SYSTEM_BACKUP
$!
$ ON ERROR THEN GOTO FAILURE
$ SET PROCESS/PRIVILEGES=ALL
$!
$ REPLY/ALL -
"Full Backup About to Begin. Open Files Will Not Be Saved"
$!
$ BACKUP /IMAGE DUA2: MUA0:FULL_BACKUP.SAV /REWIND /IGNORE=LABEL_PROCESSING
$ DISMOUNT MUA0:
$ EXIT
$!
$FAILURE:
$ WRITE SYS$OUTPUT "---> Backup failed"
$ WRITE SYS$OUTPUT ""
$ DISMOUNT MUA0:
$ EXIT. . . $! $ BACKUP/IMAGE WORK_DISK MIA0:WORK_BACK.SAV/REWIND $ BACKUP/IMAGE PAYROLL_DISK MIA0:PAYROLL_BACK.SAV $! . . .If you plan to perform any incremental backups later, include the /RECORD qualifier in the BACKUP command line.
SUBMIT/NOPRINT/AFTER="TOMORROW+2:0"/QUEUE=queue_name SYS$MANAGER:SYSTEM_BACKUP
To stop the procedure after you have submitted it, use the DELETE/ENTRY command. To find the entry number, use the SHOW ENTRY command. For example:
$SHOW ENTRYEntry Jobname Username Blocks Status ----- ------- -------- ------ ------ 14 SYS_BACKUP TPROULX Holding until 19-APR-2000 02:00 On generic batch queue CLUSTER_BATCH $DELETE/entry=583
Using a Command Procedure for Nightly Incremental
Backups
You can use a similar command procedure to perform nightly
incremental backups of your disks. It might be more convenient to
perform nightly incremental backups and weekly image backups if
either of the following conditions applies:
Suppose that you want to do nightly incremental backups at 11:00 p.m., except on Friday night, when you want to do an image backup. The following command procedure executes an incremental backup on three disks and automatically resubmits itself to run again the following night, except for Friday night.
To use the procedure, follow these steps:
$!
$! Resubmit this procedure --
$ SUBMIT/AFTER="TOMORROW+23:0" SYS$MANAGER:INCREMENTAL_BACKUP
$!
$ TODAY = f$cvtime("today",,"weekday")
$ IF TODAY .EQS. "Friday" THEN GOTO DONE
$!
$ ON ERROR THEN GOTO FAILURE
$ SET PROC/PRIV=(OPER,BYPASS)
$!
$ REPLY/ALL -
"Incremental Backup About to Begin. Open Files Will Not Be Saved"$!
$ BACKUP/RECORD/SINCE=BACKUP DRA0:[000000...] -
MIA0:INCREMENT1.SAV /LABEL=INC1
$ BACKUP/RECORD/SINCE=BACKUP DRA1:[000000...] -
MIA1:INCREMENT2.SAV /LABEL=INC2
$ BACKUP/RECORD/SINCE=BACKUP DRA2:[000000...] -
MIA2:INCREMENT3.SAV /LABEL=INC3
$ DISMOUNT MIA0:
$ DISMOUNT MIA1:
$ DISMOUNT MIA2:
$ EXIT
$!
$FAILURE:
$ WRITE SYS$OUTPUT "---> Backup failed"
$ WRITE SYS$OUTPUT ""
$ DISMOUNT MIA0:
$ DISMOUNT MIA1:
$ DISMOUNT MIA2:
$ EXIT$SUBMIT/AFTER=23 SYS$MANAGER:INCREMENTAL_BACKUP
Using an Interactive Command Procedure for
Backups
You can use the following command procedure to interactively
back up a disk to a magnetic tape.
To use the procedure, perform the following steps:
$ ! Command procedure DAILYBACK.COM $ ! $ ! Execute this command procedure interactively $ ! by entering the command @[directory]DAILYBACK $ ! at the DCL prompt. $ ! $ ! The BACKUP command in this procedure contains the $ ! output save-set qualifier /REWIND. Therefore, this $ ! command procedure always initializes the output tape. $ ! $ ON ERROR THEN GOTO FAILURE $ INQUIRE DRIVE "Enter the drive name (without a colon)" $ ALLOCATE 'DRIVE' $ INQUIRE SAVESET_SPEC "Enter the save-set specifier" $ INQUIRE LBL "Enter the tape label" $ INQUIRE EXP "Enter the tape expiration date" $ BACKUP/NOASSIST/RECORD/IGNORE=INTERLOCK/SINCE=BACKUP - [...] 'DRIVE':'SAVESET_SPEC'/REWIND/LABEL='LBL'/TAPE_EXPIRATION='EXP' $ DISMOUNT 'DRIVE' $ EXIT $! $FAILURE: $ WRITE SYS$OUTPUT "---> Backup failed" $ WRITE SYS$OUTPUT "" $ DISMOUNT 'DRIVE' $ EXIT
Backing
Up Volume Shadow Sets
Volume shadowing maintains multiple copies of the same data
on two or more disk volumes. If you use volume shadowing on your
system, you can form a shadow set by uniting individual disk volumes
(shadow set members). Volume shadowing duplicates data on each member
of the shadow set. Per-disk licensing is available for each disk
you will be including in a shadow set. This option is effective
in a cluster where you intend to shadow only a small number of disks.
However, if you have larger systems with many more disks to shadow,
traditional capacity (per-CPU) licenses may be more appropriate.
Limits on the numbers of disks allowed in shadow sets are shown in Number of Shadow Sets Supported.
| Type of Shadow Set | Sets Supported |
|---|---|
|
Single member
|
Unlimited sets
|
|
Multimember
|
Total of 400 disks in two- and three-member
sets, or both
|
These limits apply per cluster. For example, 400 total disks could be configured into 200 two-member shadow sets or into 133 three-member shadow sets per cluster. If single, two-member, and three-member shadow sets are all present on a single cluster, then a maximum of 400 disks may be contained in the two- and three-member shadow sets.
You can use the firmware implementation of RAID level 1 (shadowing) to create shadow sets using the SCSI (Small Computer Systems Interface) disks attached locally to a single SWXCR-xx controller. The StorageWorks RAID Array 210 Subsystem (SWXCR-EA or SWXCR-EB EISA Backplane RAID controllers) and the StorageWorks PCI Backplane RAID controller (SWXCR-PA or SWXCR-PB) have their own firmware implementations of RAID, levels 0, 1, and 5.
SCSI disks connected to these controllers can also be included in shadow sets created using host-based volume shadowing for OpenVMS. For example, with host-based volume shadowing, you can create a RAID1 shadow set containing two like disks, each of which is attached to a separate SWXCR-xx RAID controller located within a cluster. SCSI disks can be configured as shadow sets when attached to systems running volume shadowing for OpenVMS.
For directly connected SCSI devices that have been powered down or do not answer to polling, the elapsed time before a device is removed from a shadow set approaches one minute. In all other situations, the elapsed time closely approximates the number of seconds specified in the SHADOW_MBR_TMO parameter.
Volume shadowing checks for geometries and maximum logical block numbers (LBNs) on devices. This enables devices such as the RZ28 and the RZ28B to operate in the same shadow set. Even though their device IDs differ, their geometries and maximum LBNs will match when configured on like controllers (two HSJ controllers, for example).
When you create a shadow set, individual users access it as a virtual unit. For example, you could create a virtual unit DSA1 that consists of the disks named DUA1:, DUA2:, and DUA3. Users cannot access the individual shadow set members directly, but can perform operations on the virtual unit (DSA1:).
Because of the way volume shadowing duplicates data on each disk in the shadow set, there are special considerations for backing up a shadow set. One strategy for backing up shadow sets involves using the OpenVMS Backup utility.
 | Do not attempt to back up a shadow set by dismounting an individual shadow set member or by backing up an active shadow set member. You must dismount the entire shadow set and re-create it less one shadow set member. If you do not follow this restriction, the resultant backup copy may contain inconsistent data. |
The proper procedure for using BACKUP to back up a shadow set is described in detail in the HP Volume Shadowing for OpenVMS manual, and can be summarized as follows.
| You cannot perform an incremental backup using this procedure because the backup record date is overwritten when you add the disk volume back into the existing shadow set. |
Mounting
a Disk in a Host-Based Shadow Set
To mount a disk in the StorageWorks RAID Array 110 Subsystem
in a host-based shadow set, you must use the /OVERRIDE=NO_FORCED_ERROR
qualifier with the MOUNT command.
The StorageWorks RAID Array 110 Subsystem does not support the READ/WRITE LONG SCSI commands that are necessary for implementing the FORCED ERROR function in SCSI. Without FORCED ERROR, you must override that check by the shadowing driver.
Assisted Merging in Mixed-Architecture Clusters
Assisted
merging, also known as minimerge, is disabled if shadow sets are
mounted on an OpenVMS Alpha node and also on other types of nodes
in the same cluster. To reenable assisted merging, apply the CSCPAT (TIMA)
kit to all OpenVMS Cluster nodes mounting the shadow set.
With minimerge disabled, shadowing will continue to function normally. However, a full merge will always be done when a merge operation is required. A full merge takes considerably longer to complete than a minimerge operation; HP recommends that you install the CSCPAT (TIMA) kit.
|
|