Symbols
- .ExTeNt.nnnn files, About the files that restores generate
- @@MaNgLeD.nnnn files, About the files that restores generate
- @@MaNgLeD.nnnn_Rename files, About the files that restores generate
- @@MaNgLeD.nnnn_Symlink files, About the files that restores generate
A
- accurate licensing, Summary tab, Itemization tab, Eliminate redundant counting of clients
- ACS robot types, About Shared Storage Option components
- ACS_ vm.conf entry, ACS_mediatype entry in vm.conf
- ACS_CSI_HOSTPORT, ACS_CSI_HOSTPORT entry in vm.conf (on UNIX)
- ACS_SEL_SOCKET vm.conf entry, ACS_SEL_SOCKET entry in vm.conf
- ACS_SSI_HOSTNAME vm.conf entry, ACS_SSI_HOSTNAME entry in vm.conf
- ACS_SSI_INET_PORT
- vm.conf entry, ACS_SSI_INET_PORT entry in vm.conf (on UNIX)
- ACS_SSI_INET_PORT vm.conf entry, ACS_SSI_INET_PORT entry in vm.conf (on UNIX)
- ACS_SSI_SOCKET vm.conf entry, ACS_SSI_SOCKET entry in vm.conf
- ADJ_LSM vm.conf entry, ADJ_LSM entry in vm.conf
- All Log Entries report, Methods for determining the NetBackup transfer rate
- Allow backups to span media, About spanning media with automatic media selection
- alternate client restores
- host.xlate file, Special considerations for Domain Name Service (DNS)
- Announce DHCP interval property, About dynamic host name and IP addressing
- API_BARCODE_RULES vm.conf entry, API_BARCODE_RULES entry in vm.conf
- Arbitrated Loop Physical Address (ALPA), About hardware configuration guidelines
- AUTHORIZATION_REQUIRED vm.conf entry, AUTHORIZATION_REQUIRED entry in vm.conf in NetBackup versions 8.0 and earlier
- AUTO_PATH_CORRECTION vm.conf entry, AUTO_PATH_CORRECTION entry in vm.conf
- AUTO_UPDATE_ROBOT vm.conf entry, AUTO_UPDATE_ROBOT entry in vm.conf
- AVRD_PEND_DELAY
- vm.conf entry, About SCSI reserve operating system limitations on Windows
- AVRD_PEND_DELAY vm.conf entry, AVRD_PEND_DELAY entry in vm.conf
- AVRD_SCAN_DELAY vm.conf entry, AVRD_SCAN_DELAY entry in vm.conf
B
- Backup Exec, Shared Storage Option terms and concepts
- backup_exit_notify script, backup_exit_notify script
- backup_notify script, backup_notify script
- backups
- backup_exit_notify script, backup_exit_notify script
- backup_notify script, backup_notify script
- bpend_notify script
- UNIX client, bpend_notify script (UNIX clients)
- Windows client, bpend_notify.bat script (Windows clients)
- bpstart_notify script
- UNIX client, bpstart_notify script (UNIX clients)
- Windows client, bpstart_notify.bat script (Windows clients)
- compressed, About reading backup images with nbtar or tar32.exe
- diskfull_notify script, diskfull_notify script
- estimating time required, Factors that affect backup time
- multiplexed, About reading backup images with nbtar or tar32.exe
- session_notify script, session_notify script
- session_start_notify script, session_start_notify script
- blat mail, mail_dr_info script
- bpclient commands, bpclient commands that control client entries
- bpclntcmd utility, Verifying the connectivity
- bpdynamicclient, Configuring dynamic NetBackup clients
- bpend_notify script
- UNIX client, bpend_notify script (UNIX clients)
- Windows client, bpend_notify.bat script (Windows clients)
- bpend_notify_busy script, bpend_notify_busy script (UNIX clients)
- bpstart_notify script, bpstart_notify script (UNIX clients), bpstart_notify.bat script (Windows clients)
- UNIX client, bpstart_notify script (UNIX clients)
- Windows client, bpstart_notify.bat script (Windows clients)
- BPSTART_TIMEOUT, bpstart_notify script (UNIX clients), bpstart_notify.bat script (Windows clients)
- busy file processing
- bp.conf entries, Modifying bp.conf to configure busy file processing on UNIX
- Busy file settings property, About busy file processing on UNIX clients, Modifying bp.conf to configure busy file processing on UNIX
- configuration overview, About busy file processing on UNIX clients
- configuring on UNIX, Configuring busy file processing on UNIX
- creating action files, How NetBackup creates and uses action files on UNIX
- logs directory, About the logs directory on UNIX
- modifying bpend_notify_busy, Recommended changes for modifying bpend_notify_busy on UNIX
- BUSY_FILE_ACTION bp.conf entry, bp.conf file entries on UNIX
- BUSY_FILE_DIRECTORY bp.conf entry, bp.conf file entries on UNIX
- BUSY_FILE_PROCESSING bp.conf entry, bp.conf file entries on UNIX
C
- capacity reporting
- parameters, Scheduling reports for capacity licensing
- character device, Adding drives
- child_end_deployment_notify script, child_end_deployment_notify
- child_start_deployment_notify script, child_start_deployment_notify
- CLEAN_REQUEST_TIMEOUT vm.conf entry, CLEAN_REQUEST_TIMEOUT entry in vm.conf
- cleaning
- automatic, About library-based cleaning
- frequency-based, About frequency-based cleaning
- library-based, About library-based cleaning
- TapeAlert reactive, About TapeAlert cleaning (reactive cleaning)
- times allowed, About using a cleaning tape
- Client read timeout property, bpstart_notify script (UNIX clients), bpstart_notify.bat script (Windows clients)
- CLIENT_PORT_WINDOW vm.conf entry, CLIENT_PORT_WINDOW entry in vm.conf
- CLIENT_READ_TIMEOUT, bpstart_notify script (UNIX clients), bpstart_notify.bat script (Windows clients)
- clients
- changing host names, Updating NetBackup after changing the host name
- dynamic UNIX client, Configuring dynamic NetBackup clients
- cluster environments, About SCSI reserve limitations
- CLUSTER_NAME vm.conf entry, CLUSTER_NAME entry in vm.conf
- compressed backups, About reading backup images with nbtar or tar32.exe
- control path
- crawlreleasebyname
- vmoprcmd option, About forcing a release of an unavailable HBA's SPC-2 reservation
D
- DAYS_TO_KEEP_LOGS vm.conf entry, DAYS_TO_KEEP_LOGS entry in vm.conf
- device
- configuration wizard, Configuring Shared Storage Option devices in NetBackup
- delays, Transfer rate
- file
- robotic, Adding robots
- using with other applications, Media and device management best practices
- device allocation host, About Shared Storage Option components
- device configuration utility (see tpconfig)
- devices
- configuration wizard, About configuring SSO in NetBackup
- configuring, About Shared Storage Option prerequisites
- files, About Shared Storage Option prerequisites
- management practices, Device management best practices
- DHCP server, About dynamic host name and IP addressing
- direct I/O on Windows, About direct I/O for backups on Windows
- disk pools, creating, About the NetBackup Disk Configuration Utility
- diskfull_notify script, diskfull_notify script
- display device configuration, Displaying and writing the device configuration
- display, configuring locale, About specifying the locale of the NetBackup installation
- Domain Name Service (DNS) hostnames, Special considerations for Domain Name Service (DNS)
- drive_mount_notify script, drive_mount_notify script (on UNIX)
- drive_unmount_notify script, drive_unmount_notify script (on UNIX)
- drives
- ACS information, Adding drives
- adding, Adding drives
- character device, Adding drives
- cleaning, About tape drive cleaning, About operator-initiated cleaning
- configuring, About the tpconfig device configuration utility
- deleting, Deleting a drive
- name, Adding drives
- no rewind device, Adding drives
- robot drive number, Adding drives
- robot number that controls, Adding drives
- standalone, Adding drives
- type, Adding drives
- update configuration, Updating a drive configuration
- volume header device, Adding drives
- dynamic host name and IP addressing, About dynamic host name and IP addressing, About setting up dynamic IP addresses and host names, Configuring the NetBackup master server, Configuring dynamic NetBackup clients
E
- EMM_CONNECT_TIMOUT vm.conf entry, EMM_CONNECT_TIMOUT entry in vm.conf
- EMM_REQUEST_TIMOUT vm.conf entry, EMM_REQUEST_TIMOUT entry in vm.conf
- EMM_RETRY_COUNT vm.conf entry, EMM_RETRY_COUNT entry in vm.conf
- ENABLE_ROBOT_AUTH vm.conf entry, ENABLE_ROBOT_AUTH entry in vm.conf
- encrypted backups, Considerations for file restoration with non-NetBackup restore utilities (on UNIX)
- extended attribute files, About reading backup images with nbtar or tar32.exe
- ExTeNt.nnnn files, About the files that restores generate
F
- files
- .ExTeNt.nnnn, About the files that restores generate
- @@MaNgLeD.nnnn, About the files that restores generate
- @@MaNgLeD.nnnn_Rename, About the files that restores generate
- @@MaNgLeD.nnnn_Symlink, About the files that restores generate
- goodies scripts, NetBackup notify scripts
- name on tpreq, About requesting tapes
- positioning on tape, About reading and writing tape files
- firmware levels, About Shared Storage Option prerequisites, About hardware configuration guidelines
- FlashBackup, About reading backup images with nbtar or tar32.exe
- frequency-based drive cleaning, About frequency-based cleaning
- Front-End Terabyte (FETB) Calculation, How capacity licensing works
G
- goodies directory, NetBackup notify scripts
H
- holds
- creating, Creating a hold
- releasing, Releasing a hold
- viewing hold details, Viewing hold details
- host names
- changing client name, Updating NetBackup after changing the host name
- changing server name, How NetBackup uses host names, Updating NetBackup after changing the host name
- client peername, How NetBackup uses host names
- correct use, Host name rules
- robotic control selection, About the tpconfig device configuration utility, Adding robots
- short, How NetBackup uses host names
- host.xlate file and alternate client restores, Special considerations for Domain Name Service (DNS)
- HyperTerminal, About Shared Storage Option prerequisites
I
- INVENTORY_FILTER vm.conf entry, INVENTORY_FILTER entry in vm.conf
L
- library-based cleaning, About library-based cleaning
- licensing, About NetBackup licensing models
- for Shared Storage Option, DELETE About the Shared Storage Option license
- nbdeployutil, Tools for creating and viewing licensing reports
- locale, configuring, About specifying the locale of the NetBackup installation
M
- mail_dr_info.cmd, mail_dr_info script
- mail_dr_info.sh, mail_dr_info script
- MAP_CONTINUE_TIMEOUT vm.conf entry, MAP_CONTINUE_TIMEOUT entry in vm.conf
- MAP_ID, vm.conf entry, MAP_ID entry in vm.conf
- Maximum concurrent drives for backup, About configuring NetBackup storage units and backup policies
- media
- best practices, Media management best practices
- formats, Media formats
- selection algorithm, About selecting media in robots, About selecting media in standalone drives
- spanning, About spanning media with automatic media selection, About spanning media
- media and device management
- best practices, Media and device management best practices
- performance and troubleshooting, Media and device performance and troubleshooting
- Media Manager
- best practices, Media and device management best practices
- configuration file, About the vm.conf configuration file
- security, SERVER entry in vm.conf in NetBackup versions 8.0 and earlier
- media_deassign_notify script, media_deassign_notify script
- MEDIA_ID_BARCODE_CHARS vm.conf entry, MEDIA_ID_BARCODE_CHARS entry in vm.conf
- MEDIA_ID_PREFIX vm.conf entry, MEDIA_ID_PREFIX entry in vm.conf
- MM_SERVER_NAME vm.conf entry, MM_SERVER_NAME entry in vm.conf
- multiplexing (MPX)
- backups, Media formats
- recovering backups, About reading backup images with nbtar or tar32.exe
- tape format, Media formats
N
- named data streams, About reading backup images with nbtar or tar32.exe
- nbdeployutil, Tools for creating and viewing licensing reports
- nbemm, About Shared Storage Option components
- nbemm/DA
- definition, About Shared Storage Option components
- nbholdutil -create, Creating a hold
- nbmail.cmd, nbmail.cmd script (on Windows)
- nbtar, About reading backup images with nbtar or tar32.exe, About the files that restores generate
- NDMP, About SCSI reserve limitations
- client backups, About reading backup images with nbtar or tar32.exe
- host credentials, Configuring host credentials
- NetBackup Access Control (NBAC)
- NetBackup Disk Configuration Utility
- network transfer rate, Methods for determining the NetBackup transfer rate
- notification scripts, NetBackup notify scripts
O
- Online Help for tpconfig, About the tpconfig utility menu
- open files (see busy-file processing)
- OpsCenter
- license reporting, Tools for creating and viewing licensing reports
P
- parent_end_deployment_notify script, parent_end_deployment_notify
- parent_end_notify script, parent_end_notify script
- parent_start_deployment_notify script, parent_start_deployment_notify
- parent_start_notify script, parent_start_notify script
- peername of client, How NetBackup uses host names
- pending_request_notify script, pending_request_notify script
- positioning tape files, About reading and writing tape files
- PREFERRED_GROUP vm.conf entry, PREFERRED_GROUP entry in vm.conf
- printing device configuration, Displaying and writing the device configuration
R
- random ports, setting on server, RANDOM_PORTS entry in vm.conf
- RANDOM_PORTS vm.conf entry, RANDOM_PORTS entry in vm.conf
- raw partitions, About reading backup images with nbtar or tar32.exe
- reactive cleaning, About TapeAlert cleaning (reactive cleaning)
- reading tape files, About reading and writing tape files
- release, Releasing a hold
- removing tape files, About removing tape files
- reporting, capacity, Scheduling reports for capacity licensing
- reporting, NEVC, Scheduling reports for NetBackup Enterprise Virtual Client (NEVC) licensing
- reporting, traditional, Scheduling reports for traditional licensing
- requests
- user tape, About requesting tapes
- REQUIRED_INTERFACE vm.conf entry, REQUIRED_INTERFACE entry in vm.conf
- RESERVATION CONFLICT status, About SCSI reservation conflicts
- restore_notify script, restore_notify script
- restores
- from a non-NetBackup tar, Restoring files with non-NetBackup restore utilities (on UNIX)
- restore_notify script, restore_notify script
- rewind
- devices
- none, Adding drives
- tape files, About reading and writing tape files
- robotic cleaning, About library-based cleaning
- robots
- adding, Adding robots
- configuring, About the tpconfig device configuration utility
- control host, About the tpconfig device configuration utility, Adding robots
- deleting, Deleting a robot
- device file, Adding robots
- drive, Adding drives
- number, Adding robots, Adding drives
- sharing without SSO, How to share robotic libraries without using the Shared Storage Option
- type, Adding robots
- update configuration, Updating a robot configuration
S
- SAN media server, About Shared Storage Option components, Shared Storage Option terms and concepts
- SAN Shared Storage Option (see SSO), About the Shared Storage Option
- scan host, About Shared Storage Option components
- scripts
- bpend_notify_busy, bpend_notify_busy script (UNIX clients)
- bpstart_notify, bpstart_notify script (UNIX clients), bpstart_notify.bat script (Windows clients)
- child_end_deployment_notify, child_end_deployment_notify
- child_start_deployment_notify, child_start_deployment_notify
- drive_mount_notify, drive_mount_notify script (on UNIX)
- drive_unmount_notify, drive_unmount_notify script (on UNIX)
- goodies, NetBackup notify scripts
- notification, NetBackup notify scripts
- parent_end_deployment_notify, parent_end_deployment_notify
- parent_end_notify, parent_end_notify script
- parent_start_deployment_notify, parent_start_deployment_notify
- parent_start_notify, parent_start_notify script
- shared_drive_notify, DELETE About reserving or releasing shared devices, Frequently asked questions about Shared Storage Option, shared_drive_notify script
- SCSI persistent reserve, How NetBackup reserves drives
- SCSI reserve and release, How NetBackup reserves drives
- break a reservation, About SPC-2 SCSI reserve commands, Breaking a reservation
- error recovery, About forcing a release of an unavailable HBA's SPC-2 reservation
- limitations, About SCSI reserve limitations, About SCSI reserve operating system limitations on Windows
- PEND status, About SCSI reservation conflicts, About forcing a release of an unavailable HBA's SPC-2 reservation
- requirements, About SCSI reserve requirements
- RESERVATION CONFLICT, About SPC-2 SCSI reserve commands, About SCSI reservation conflicts
- SCSI-to-fibre
- SERVER
- vm.conf entry, How to access media and devices on other hosts
- SERVER vm.conf entry, SERVER entry in vm.conf in NetBackup versions 8.0 and earlier
- servers
- changing host names, How NetBackup uses host names, Updating NetBackup after changing the host name
- multiple master servers, About multiple NetBackup master servers
- multiple media servers, About multiple media servers with one master server
- SAN media server, About Shared Storage Option components
- session_notify script, session_notify script
- session_start_notify script, session_start_notify script
- shared drives (see SSO)
- definition, Shared Storage Option terms and concepts
- shared library support, How to share robotic libraries without using the Shared Storage Option
- shared robots
- Shared storage option
- license, About the Shared Storage Option
- Shared Storage Option
- license for, DELETE About the Shared Storage Option license
- shared_drive_notify script, DELETE About reserving or releasing shared devices, Frequently asked questions about Shared Storage Option
- Simple Mail Transfer Protocol, nbmail.cmd script (on Windows)
- Solaris
- extended attributes, About reading backup images with nbtar or tar32.exe
- spanning media, About spanning media with automatic media selection, About spanning media, Media formats
- SSO
- definition, About the Shared Storage Option
- device allocation host, About Shared Storage Option components
- Device Allocation Host Summary, Shared Storage Option summary reports
- hardware requirements, About the Shared Storage Option
- scan host, About Shared Storage Option components
- Shared Drive Summary, Shared Storage Option summary reports
- supported SAN hardware, Frequently asked questions about Shared Storage Option
- terminology, Shared Storage Option terms and concepts
- vm.conf entries, SSO_HOST_NAME entry in vm.conf
- SSO components configuration
- examples, About Shared Storage Option components
- SSO_DA_REREGISTER_INTERVAL vm.conf entry, SSO_DA_REREGISTER_INTERVAL entry in vm.conf
- SSO_DA_RETRY_TIMEOUT vm.conf entry, SSO_DA_RETRY_TIMEOUT entry in vm.conf
- SSO_HOST_NAME vm.conf entry, SSO_HOST_NAME entry in vm.conf
- standalone drive
- tpconfig, Adding drives
- standalone drives
- disabling extensions, About disabling standalone drive extensions
- Storage area network (SAN), About the Shared Storage Option, Shared Storage Option terms and concepts, About Shared Storage Option prerequisites, About hardware configuration guidelines
- storage servers, creating, About the NetBackup Disk Configuration Utility
T
- tape configuration utility (see tpconfig)
- tape drives, cleaning, About tape drive cleaning
- tape formats, Media formats
- tape spanning, About spanning media with automatic media selection, About spanning media
- TapeAlert
- about, About TapeAlert
- cleaning flags, About operator-initiated cleaning
- frequency-based cleaning, About TapeAlert and frequency-based cleaning
- log codes, TapeAlert logs and codes
- reactive cleaning, About TapeAlert cleaning (reactive cleaning)
- requirements, About TapeAlert requirements
- tapes and tape files
- density, About requesting tapes
- positioning tape file, About reading and writing tape files
- reading and writing, About reading and writing tape files
- removing tape files, About removing tape files
- requesting tapes, About requesting tapes
- rewinding, About reading and writing tape files
- volume pool assignment, About requesting tapes
- tar32.exe, About reading backup images with nbtar or tar32.exe
- tested SAN components, Frequently asked questions about Shared Storage Option
- Timeouts host properties, bpstart_notify script (UNIX clients), bpstart_notify.bat script (Windows clients)
- tpconfig
- about, About the tpconfig device configuration utility
- adding a drive, Adding drives
- adding a robot, Adding robots
- adding NDMP host credentials, Configuring host credentials
- deleting a drive, Deleting a drive
- deleting robots, Deleting a robot
- menus, About the tpconfig utility menu
- Online Help, About the tpconfig utility menu
- printing device configuration, Displaying and writing the device configuration
- starting, Starting the tpconfig device configuration utility
- stopping, Starting the tpconfig device configuration utility
- update drive configuration, Updating a drive configuration
- update robot configuration, Updating a robot configuration
- tpreq, using to request tapes, About requesting tapes
- tpunmount, using to remove tape files, About removing tape files
- transfer rate, Transfer rate, Methods for determining the NetBackup transfer rate
U
- unified logging, DAYS_TO_KEEP_LOGS entry in vm.conf
- userreq_notify script, userreq_notify script
- using devices with other applications, Media and device management best practices
V
- VERBOSE, vm.conf entry, VERBOSE entry in vm.conf
- Veritas Backup Exec, Shared Storage Option terms and concepts
- vm.conf file
- ACS_ entries, ACS_mediatype entry in vm.conf
- ACS_CSI_HOSTPORT entries, ACS_CSI_HOSTPORT entry in vm.conf (on UNIX)
- ACS_SEL_SOCKET entries, ACS_SEL_SOCKET entry in vm.conf
- ACS_SSI_HOSTNAME entries, ACS_SSI_HOSTNAME entry in vm.conf
- ACS_SSI_INET_PORT entries, ACS_SSI_INET_PORT entry in vm.conf (on UNIX)
- ACS_SSI_SOCKET entries, ACS_SSI_SOCKET entry in vm.conf
- ADJ_LSM entries, ADJ_LSM entry in vm.conf
- API_BARCODE_RULES entries, API_BARCODE_RULES entry in vm.conf
- AUTHORIZATION_REQUIRED entries, AUTHORIZATION_REQUIRED entry in vm.conf in NetBackup versions 8.0 and earlier
- AUTO_PATH_CORRECTION entries, AUTO_PATH_CORRECTION entry in vm.conf
- AUTO_UPDATE_ROBOTentries, AUTO_UPDATE_ROBOT entry in vm.conf
- AVRD_PEND_DELAY entries, AVRD_PEND_DELAY entry in vm.conf
- AVRD_SCAN_DELAY entries, AVRD_SCAN_DELAY entry in vm.conf
- CLEAN_REQUEST_TIMEOUT entries, CLEAN_REQUEST_TIMEOUT entry in vm.conf
- CLIENT_PORT_WINDOW entries, CLIENT_PORT_WINDOW entry in vm.conf
- CLUSTER_NAME entry, CLUSTER_NAME entry in vm.conf
- DAYS_TO_KEEP_LOGS entries, DAYS_TO_KEEP_LOGS entry in vm.conf
- EMM_CONNECT_TIMOUT entries, EMM_CONNECT_TIMOUT entry in vm.conf
- EMM_REQUEST_TIMOUT entries, EMM_REQUEST_TIMOUT entry in vm.conf
- ENABLE_ROBOT_AUTH entries, ENABLE_ROBOT_AUTH entry in vm.conf
- INVENTORY_FILTER entries, EMM_RETRY_COUNT entry in vm.conf, INVENTORY_FILTER entry in vm.conf
- MAP_CONTINUE_TIMEOUT entries, MAP_CONTINUE_TIMEOUT entry in vm.conf
- MAP_ID entries, MAP_ID entry in vm.conf
- MEDIA_ID_BARCODE_CHARS entries, MEDIA_ID_BARCODE_CHARS entry in vm.conf
- MEDIA_ID_PREFIX entries, MEDIA_ID_PREFIX entry in vm.conf
- MM_SERVER_NAME entry, MM_SERVER_NAME entry in vm.conf
- overview, About the vm.conf configuration file
- PREFERRED_GROUP entries, PREFERRED_GROUP entry in vm.conf
- RANDOM_PORTS entries, RANDOM_PORTS entry in vm.conf
- REQUIRED_INTERFACE entry, REQUIRED_INTERFACE entry in vm.conf
- SERVER entries, SERVER entry in vm.conf in NetBackup versions 8.0 and earlier
- SSO_DA_REREGISTER_INTERVAL entries, SSO_DA_REREGISTER_INTERVAL entry in vm.conf
- SSO_DA_RETRY_TIMEOUT entries, SSO_DA_RETRY_TIMEOUT entry in vm.conf
- SSO_HOST_NAME entries, SSO_HOST_NAME entry in vm.conf
- VERBOSE entries, VERBOSE entry in vm.conf
- vm.conf file, adding SERVER entries, How to access media and devices on other hosts
- volume groups examples, Volume pool and volume group examples
- volume header device, Adding drives
- volume pools examples, Volume pool and volume group examples
- VxFS
- extent attributes, About the files that restores generate
- named data streams, About reading backup images with nbtar or tar32.exe
W
- Windows, direct I/O, About direct I/O for backups on Windows
- wizards
- device configuration, About configuring SSO in NetBackup
- shared drive configuration, Configuring Shared Storage Option devices in NetBackup
- writing tape files, About reading and writing tape files