Cleaning a Tape Drive using Oracle Secure
Backup
Article by author Jeff Hunter
Oracle Secure Backup (OSB) provides a
reliable, centralized tape backup management solution which can
be used to protect file system data as well as Oracle Database
files. For Oracle Recovery Manager (RMAN) users, the Oracle
Secure Backup SBT interface enables you to use the RMAN to back
up and restore Oracle Database files to and from tape. Oracle
Secure Backup supports nearly all tape drives and tape libraries
in Storage Area Network (SAN) and Small Computer System
Interface (SCSI) environments.
Oracle Secure Backup provides the ability to perform
automatic tape drive cleaning as well as the option to manually
clean a tape drive. The following article provides a brief
overview of the tape cleaning functionality built into OSB.
After importing a cleaning cartridge to the tape library, you
need to inform OSB that the media just inserted is not a data
volume but rather a cleaning tape. Inserting a cleaning
cartridge and performing an inventory through OSB while not
indicating to OSB that a cleaning cartridge was inserted will
result in OSB thinking the new media is a normal data tape. If
you were to attempt a tape cleaning operation, the following
errors would occur:
ob> clean --drive tape1 --force --use 8
Error: can't execute command - specified element does not hold a cleaning tape
ob> clean --drive tape1 --force
Error: can't execute command - could not find a usable cleaning tape
Import the cleaning cartridge into a vacant storage element
(i.e. storage element 8). Next, notify OSB of the newly imported
cleaning cartridge, using the
insertvol
command. In my example, I already used the cleaning tape once on
another drive so I indicate
--uses 1
ob> insertvol --library lib1 clean --uses 1 --maxuses 15 8
Manually Cleaning a Tape Drive
Use the
clean
command in obtool
to request a manual cleaning be performed on the selected tape
drive. The --force
option will force the tape to be cleaned. If there is a tape
loaded in the tape drive, then selecting this option unloads the
tape, loads the cleaning tape, cleans the tape drive, and then
reloads the tape that was originally in the tape drive.
Import the cleaning cartridge into a vacant storage element
(i.e. storage element 8). In my example, I already used the
cleaning tape once on another drive so I indicate --uses 1
ob> insertvol --library lib1 clean --uses 1 --maxuses 15 8
ob> lsvol --library lib1
Inventory of library lib1:
in 1: volume RMAN-TESTDB1-MF-000006, 83909632 kb remaining, content manages reuse
in 2: volume RMAN-TESTDB1-MF-000004, 87050240 kb remaining, content manages reuse
in 3: occupied
in 4: occupied
in 5: occupied
in 6: occupied
in 7: occupied
in 8: cleaning tape: 1 use, 14 remaining
ob> clean --drive tape1 --force --use 8
ob> lsvol --library lib1
Inventory of library lib1:
in 1: volume RMAN-TESTDB1-MF-000006, 83909632 kb remaining, content manages reuse
in 2: volume RMAN-TESTDB1-MF-000004, 87050240 kb remaining, content manages reuse
in 3: occupied
in 4: occupied
in 5: occupied
in 6: occupied
in 7: occupied
in 8: cleaning tape: 2 uses, 13 remaining
Configuring Automatic Tape Drive Cleaning
Oracle Secure Backup allows you to
configure a tape library to automatically perform a type drive
cleaning whenever a tape drive reports that it needs cleaning or
when a specified usage time has elapsed.
Use the
--autoclean option of the
mkdev or
chdev commands of
obtool to
configure the library to perform automatic cleaning. When the
autoclean option
is set to yes,
the cleaning cycle is initiated either when a tape drive reports
that it needs cleaning or when a specified usage time has
elapsed. Oracle Secure Backup checks for cleaning requirements
when a cartridge is either loaded into or unloaded from a tape
drive. If at that time a cleaning is required, then Oracle
Secure Backup performs the following steps:
-
Loads a cleaning cartridge
-
Waits for the cleaning cycle to complete
-
Replaces the cleaning cartridge in its original storage
element
-
Continues with the requested load or unload
The following example queries the tape library configuration
for lib1. As you
can see, the autoclean option is not currently set:
ob> lsdev --type library --long lib1
lib1:
Device type: library
Model: [none]
Serial number: [none]
In service: yes
Debug mode: no
Barcode reader: default (hardware-selected)
Barcodes required: no
Auto clean: no
Clean interval: (not set)
Clean using emptiest: no
Ejection type: auto
Min writable volumes: 0
UUID: 89064982-0df2-102c-8f89-00146cc1a7c7
Attachment 1:
Host: packmule
Raw device: /dev/sg0
To enable automatic tape drive cleaning,
use the chdev
option:
ob> chdev --type library --autoclean yes --cleanemptiest no lib1
Another query on the tape library device
shows that auto-cleaning is enabled:
ob> lsdev --type library --long lib1
lib1:
Device type: library
Model: [none]
Serial number: [none]
In service: yes
Debug mode: no
Barcode reader: default (hardware-selected)
Barcodes required: no
Auto clean: yes
Clean interval: (not set)
Clean using emptiest: no
Ejection type: auto
Min writable volumes: 0
UUID: 89064982-0df2-102c-8f89-00146cc1a7c7
Attachment 1:
Host: packmule
Raw device: /dev/sg0
In addition to simply enabling
auto-cleaning, OSB allows you to specify two other options:
--cleanemptiest/-E
{yes | no}
Specifies which cleaning tape to use. This
option is useful when a tape library contains multiple cleaning
tapes. The default value of yes specifies the emptiest cleaning
tape, which causes cleaning tapes to round robin as cleanings
are required. The no value specifies that obtool should use the
least used cleaning tape, which uses each cleaning tape until it
is exhausted, then uses the next cleaning tape until it is
exhausted, and so forth.
--cleaninterval/-i
{duration | off}
Specifies whether there should be a
cleaning interval, and if so, the duration of the interval. The
default is off. The duration is the interval of time a tape
drive is used before a cleaning cycle begins. If automatic tape
drive cleaning is enabled, then duration indicates the interval
between cleaning cycles. For tape drives that do not report
cleaning requirements, you can specify a cleaning interval, for
example, 30days.
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