Problem statement:Lets assume you have a production database of 50 TB in size in and you maintain it in ASM file system with normal redundancy.This implies your storage utilization is 100 TB.In addition you maintain full size several copies of non-production (like dev,test,uat,pre-prod etc) as required by project team. So at some point of time you will reach in a situation where your storage has exceeded warning threshold. How will you handle this situation?
Solution: This problem can be solved using oracle acfs filesystem.Please see below link for detailed documentation
https://www.oracle.com/a/tech/docs/acfs-snapshot-best-practices.pdf
- Create database clone from production database using acfs file system.That will work as a master database.
- Create a snapshot database out of it in same acfs file system for your non-prod environments.
Initially snapshot created from master database will have only some metadata information.If you make changes in master database only the changed block will be copied to the snapshot file system so that snapshot db has consistent data.Basically it uses copy on write mechanism for this storage snapshot.
Without giving big lectures lets walk in the ground of reality.Please find below technical steps which will guide you to prepare to adopt this approach.
Technical steps:
1.
Create 3 volumes like below
asmcmd volcreate -G data -s 5120G DATA
asmcmd volcreate -G reco -s 500G RECO
asmcmd volcreate -G data -s 200G REDO
2.
Create file system out of that volume
asmcmd
volinfo -G DATA DATA
Diskgroup Name: DATA
Volume Name: DATA
Volume Device: /dev/asm/data-132
State: ENABLED
Size (MB): 5242880
Resize Unit (MB): 64
Redundancy: MIRROR
Stripe Columns: 8
Stripe Width (K): 1024
Usage:
Mountpath:
/sbin/mkfs -t acfs /dev/asm/data-132
mkfs.acfs: version = 19.0.0.0.0
mkfs.acfs: on-disk version = 46.0
mkfs.acfs: volume = /dev/asm/data-132
mkfs.acfs: volume size = 5497558138880 (
5.00 TB )
mkfs.acfs: Format complete.
asmcmd
volinfo -G RECO RECO
Diskgroup Name: RECO
Volume Name: RECO
Volume Device: /dev/asm/reco-262
State: ENABLED
Size (MB): 512000
Resize Unit (MB): 64
Redundancy: MIRROR
Stripe Columns: 8
Stripe Width (K): 1024
Usage:
Mountpath:
/sbin/mkfs -t acfs /dev/asm/reco-262
mkfs.acfs: version = 19.0.0.0.0
mkfs.acfs: on-disk version = 46.0
mkfs.acfs: volume = /dev/asm/reco-262
mkfs.acfs: volume size = 536870912000 ( 500.00 GB )
mkfs.acfs: Format complete.
asmcmd volinfo -G DATA REDO
Diskgroup
Name: DATA
Volume
Name: REDO
Volume
Device: /dev/asm/redo-132
State:
ENABLED
Size
(MB): 204800
Resize
Unit (MB): 64
Redundancy:
MIRROR
Stripe
Columns: 8
Width (K): 1024
Usage:
Mountpath:
/sbin/mkfs -t acfs /dev/asm/redo-132
mkfs.acfs: version = 19.0.0.0.0
mkfs.acfs: on-disk version = 46.0
mkfs.acfs: volume = /dev/asm/redo-132
mkfs.acfs: volume size = 214748364800 ( 200.00 GB )
mkfs.acfs: Format complete.
3.
Create below mount point from root user
mkdir /data;chown oracle:dba /data;ls -ldr
/data
drwxr-xr-x 2 oracle dba 4096 Jan 7 14:13 /data
mkdir /reco;chown oracle:dba /reco;ls -ldr
/reco
drwxr-xr-x 2 oracle dba 4096 Jan 7 14:15 /reco
mkdir /redo;chown oracle:dba /redo;ls -ldr
/redo
4.
Mount the acfs file syetm using below command
grep grid
/u01/app/oraInventory/ContentsXML/inventory.xml
<HOME NAME="OraGrid19000"
LOC="/u01/app/19.0.0.0/grid" TYPE="O" IDX="1"
CRS="true"/>
/u01/app/19.0.0.0/grid/bin/srvctl add
filesystem -device /dev/asm/data-132 -path /data -user oracle -mountowner
oracle -mountgroup dba -mountperm 755
/u01/app/19.0.0.0/grid/bin/srvctl add
filesystem -device /dev/asm/reco-262 -path /reco -user oracle -mountowner
oracle -mountgroup dba -mountperm 755
/u01/app/19.0.0.0/grid/bin/srvctl add
filesystem -device /dev/asm/redo-132 -path /redo -user oracle -mountowner
oracle -mountgroup dba -mountperm 755
5.
Start the acfs file system
/u01/app/19.0.0.0/grid/bin/srvctl start
filesystem -d /dev/asm/data-132
/u01/app/19.0.0.0/grid/bin/srvctl start
filesystem -d /dev/asm/reco-262
/u01/app/19.0.0.0/grid/bin/srvctl start
filesystem -d /dev/asm/redo-132
6.
Check the acfs file system status
/u01/app/19.0.0.0/grid/bin/crsctl stat res
ora.data.data.acfs ora.data.redo.acfs ora.reco.reco.acfs -t
--------------------------------------------------------------------------------
Name Target State
Server State
details
--------------------------------------------------------------------------------
Local Resources
--------------------------------------------------------------------------------
ora.data.data.acfs
ONLINE ONLINE
testoda01a mounted
on /data,
STABLE
ONLINE ONLINE
testsoda01b mounted
on /data,
STABLE
ora.data.redo.acfs
ONLINE ONLINE
testoda01a mounted
on /redo,
STABLE
ONLINE ONLINE
testoda01b mounted
on /redo,
STABLE
ora.reco.reco.acfs
ONLINE ONLINE
testoda01a mounted
on /reco,
STABLE
ONLINE ONLINE
testoda01b mounted
on /reco,
STABLE
df -h | grep
/dev/asm/data-132 5.0T 11G
5.0T 1% /data
/dev/asm/reco-262 500G 1.6G
499G 1% /reco
/dev/asm/redo-132 200G 1020M 200G
1% /redo
7.
Downloade gDBclone rpm using below link
provided in gDBClone Powerful Database Clone/Snapshot Management Tool (Doc ID
2099214.1)
8.
Identify DB home to use for clone
/opt/gDBClone/gDBClone.bin listhomes
INFO: 2025-01-07 14:50:50: Please check the
logfile '/opt/gDBClone/out/log/gDBClone_2758.log' for more details
│▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒│
gDBClone - Version: 3.0.6-18
Copyright (c) 2012-2024 Oracle and/or its
affiliates.
--------------------------------------------------------
Author: Ruggero Citton
<ruggero.citton@oracle.com>
RAC
Pack, Cloud Innovation and Solution Engineering Team
│▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒│
Oracle Home Name Home Location
---------------- ------------
OraDB19000_home1 /u01/app/oracle/product/19.0.0.0/dbhome_1
9.
Create password file which can be used
later
/opt/gDBClone/gDBClone.bin syspwf
-syspwf /u01/app/oracle/product/19.0.0.0/dbhome_1/dbs/orapwMSTR
│▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒│
gDBClone - Version: 3.0.6-18
Copyright (c) 2012-2024 Oracle and/or its
affiliates.
--------------------------------------------------------
Author: Ruggero Citton
<ruggero.citton@oracle.com>
RAC Pack, Cloud Innovation and Solution
Engineering Team
│▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒│
Please enter the password to
encrypt:
Please re-enter the password to
encrypt:
SYS password file created as
/u01/app/oracle/product/19.0.0.0/dbhome_1/dbs/orapwMSTR
10. Use
below command to clone from source database
/opt/gDBClone/gDBClone.bin clone -sdbname
cist4.world -sbckloc /orabak5z/tusldoda01a/rman/CIST4 -tdbname mstr -tdbhome OraDB19000_home1 -dataacfs /data -redoacfs /redo
-recoacfs /reco -racmod 0 -channels 8 -syspwf
/u01/app/oracle/product/19.0.0.0/dbhome_1/dbs/orapwMSTR
INFO: 2025-01-07 15:13:06: Please check the
logfile '/opt/gDBClone/out/log/gDBClone_75659.log' for more details
NOTE: Here I have used backup based
duplication and that is why used parameter sbckloc
│▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒│
gDBClone - Version: 3.0.6-18
Copyright (c) 2012-2024 Oracle and/or its
affiliates.
--------------------------------------------------------
Author: Ruggero Citton
<ruggero.citton@oracle.com>
RAC
Pack, Cloud Innovation and Solution Engineering Team
│▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒│
MacroStep1 - Getting information
and validating setup...
INFO: 2025-01-08 14:51:53:
Validating environment
INFO: 2025-01-08 14:51:53: Checking
superuser usage
INFO: 2025-01-08 14:51:53: Checking
'mstr' target database name
INFO: 2025-01-08 14:51:53: Checking
target database home 'OraDB19000_home1' existence
INFO: 2025-01-08 14:51:53: Checking
if Oracle Restart
INFO: 2025-01-08 14:51:53: Checking
source backup location /orabak5z/tusldoda01a/rman/CIST4...
INFO: 2025-01-08 14:51:53: Getting
ORACLE_BASE path from orabase
INFO: 2025-01-08 14:51:53: Checking
target database 'mstr' existence
INFO: 2025-01-08 14:51:53: Checking
target database 'mstr' registered instance
INFO: 2025-01-08 14:51:55: Checking
ACFS snapshot 'mstr' existence under '/data'
INFO: 2025-01-08 14:51:56: Checking
listener on 'tuslsoda01:1521'
INFO: 2025-01-08 14:51:56: Checking
ACFS options
INFO: 2025-01-08 14:51:56:
...checking if dataacfs '/data' is an ACFS file system
INFO: 2025-01-08 14:51:56:
...checking if redoacfs '/redo' is an ACFS file system
INFO: 2025-01-08 14:51:56:
...checking if recoacfs '/reco' is an ACFS file system
SUCCESS: 2025-01-08 14:51:59:
Environment validation complete
MacroStep2 - Setting up clone
environment...
INFO: 2025-01-08 14:51:59: Creating
local pfile
INFO: 2025-01-08 14:51:59: Creating
local password file
INFO: 2025-01-08 14:51:59: Creating
local Audit folder
INFO: 2025-01-08 14:51:59: Checking
local auxiliary listener existence
INFO: 2025-01-08 14:51:59: Creating
local auxiliary listener
INFO: 2025-01-08 14:51:59: Starting
auxiliary listener
INFO: 2025-01-08 14:51:59: Sleeping
60 secs, please wait...
INFO: 2025-01-08 14:52:59: Setting
up ACFS storage
INFO: 2025-01-08 14:52:59: Creating
RMAN dynamic scripts
INFO: 2025-01-08 14:53:00: Cloning
to target ACFS from backup location '/orabak5z/tusldoda01a/rman/CIST4'
INFO: 2025-01-08 14:53:00:
...creating RMAN duplicate script
INFO: 2025-01-08 14:53:00:
...creating RMAN spfile script
INFO: 2025-01-08 14:53:00: Creating
RMAN script for spfile target to ACFS
INFO: 2025-01-08 14:53:00:
Instantiating clone database
SUCCESS: 2025-01-08 14:53:00:
Environment setup complete
MacroStep3 - Cloning database
'cist4.world'...
INFO: 2025-01-08 14:53:00: Database
clone from backup in progress, please wait...
INFO: 2025-01-08 14:53:00: (this can take a while depending on
database size and/or network speed)
INFO: 2025-01-08 14:53:00: (rman spool file
'/opt/gDBClone/out/log/rman_clone_79140.log')
INFO: 2025-01-08 16:18:58: Create
PFile from SPFile
INFO: 2025-01-08 16:20:15: Register
'mstr' database as cluster resource
INFO: 2025-01-08 16:20:16: Creating
password file for 'mstr'
INFO: 2025-01-08 16:20:16: Register
ACFS passwordfile '/data/.ACFS/snaps/mstr/MSTR/password/orapwmstr'
INFO: 2025-01-08 16:20:17: Updating
SPFile
INFO: 2025-01-08 16:20:20: Updating
local pfile
INFO: 2025-01-08 16:20:20:
Modifying DB instance
INFO: 2025-01-08 16:20:21: Setup
ACFS dependency
WARNING: 2025-01-08 16:20:24: Copy
'/u01/app/oracle/product/19.0.0.0/dbhome_1/network/admin/tnsnames.ora' to
remote node 'tuslsoda01a' failed
INFO: 2025-01-08 16:20:24: Starting
database : mstr
SUCCESS: 2025-01-08 16:20:43: Clone
database 'mstr' created successfully
INFO: 2025-01-08 16:20:43: Starting
database 'mstr'
SUCCESS: 2025-01-08 16:20:44:
Successfully created clone database 'mstr'
You have new mail in
/var/spool/mail/root
11.
Check new database using tool
/opt/gDBClone/gDBClone.bin listdbs
INFO: 2025-01-08 16:25:16: Please check the
logfile '/opt/gDBClone/out/log/gDBClone_75342.log' for more details
│▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒│
gDBClone - Version: 3.0.6-18
Copyright (c) 2012-2024 Oracle and/or its
affiliates.
--------------------------------------------------------
Author: Ruggero Citton
<ruggero.citton@oracle.com>
RAC
Pack, Cloud Innovation and Solution Engineering Team
│▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒│
Database Name Database Type Database Role Master/Snapshot Location/Parent
------------- ------------- ------------- --------------- ---------------
oemtest SINGLE PRIMARY Master /u02/app/oracle/oradata
mstr SINGLE PRIMARY Master /data/.ACFS/snaps/
12. Create
a snap db using the tool
/opt/gDBClone/gDBClone.bin snap -sdbname mstr
-tdbname dev -tdbhome "OraDB19000_home1" -racmod 0 -syspwf
/u01/app/oracle/product/19.0.0.0/dbhome_1/dbs/orapwMSTR
│▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒│
gDBClone - Version: 3.0.6-18
Copyright (c) 2012-2024 Oracle and/or its
affiliates.
--------------------------------------------------------
Author: Ruggero Citton
<ruggero.citton@oracle.com>
RAC
Pack, Cloud Innovation and Solution Engineering Team
│▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒│
MacroStep1 - Getting information and
validating setup...
INFO: 2025-01-08 16:30:23: Checking whether
the database 'mstr' is on Exascale
INFO: 2025-01-08 16:30:25: Checking whether
the database 'mstr' is on ACFS snapshot
INFO: 2025-01-08 16:30:28: Validating
environment...
INFO: 2025-01-08 16:30:28: Superuser usage
check
INFO: 2025-01-08 16:30:28: Clusterware
running check
INFO: 2025-01-08 16:30:28: Oracle Restart
check
INFO: 2025-01-08 16:30:28: Minimum crs
activeversion check
INFO: 2025-01-08 16:30:28: Checking source
database 'mstr' existence
INFO: 2025-01-08 16:30:28: Checking source
database 'mstr' if running
INFO: 2025-01-08 16:30:29: ...checking if
target database home 'OraDB19000_home1' exists
INFO: 2025-01-08 16:30:29: Checking source
database 'mstr' connectivity
INFO: 2025-01-08 16:30:34: Checking source
database 'mstr' and target dbhome version
INFO: 2025-01-08 16:30:39: Checking target
database 'dev' name
INFO: 2025-01-08 16:30:39: Checking target
database 'dev' existence
INFO: 2025-01-08 16:30:39: Checking target
database 'dev' registered instance
INFO: 2025-01-08 16:30:43: Checking target
database 'dev' exists as ACFS snapshot in '/data'
INFO: 2025-01-08 16:30:43: Checking if
source database 'mstr' is snapable...
INFO: 2025-01-08 16:30:44: ...checking
whether the database 'mstr' is entirely on ACFS
INFO: 2025-01-08 16:30:46: ...checking
whether the database 'mstr' is a primary/physical standby database.
INFO: 2025-01-08 16:30:47: ...checking
whether the database 'mstr' is in rw/ro mode
INFO: 2025-01-08 16:30:50: ...checking
whether the database 'mstr' is a multitenant
INFO: 2025-01-08 16:30:55: ...checking
whether the database 'mstr' is running as backup mode
INFO: 2025-01-08 16:30:58: ...checking
whether the database 'mstr' is running in archivelog mode
INFO: 2025-01-08 16:31:00: ...checking
whether all database 'mstr' datafiles are available
INFO: 2025-01-08 16:31:03: ...checking if
there are offline datafiles
SUCCESS: 2025-01-08 16:31:05: Environment
validation complete
MacroStep2 - Getting database ACFS
snapshot...
INFO: 2025-01-08 16:31:05: Cloning source
database 'mstr' using ACFS snapshot
INFO: 2025-01-08 16:31:21: Entering into
SNAP database creation phase 1
INFO: 2025-01-08 16:31:21: ...getting
required information to get consistent database snapshot
WARNING: 2025-01-08 16:31:26: Do not
perform any structural change to database 'mstr' till snapshot database 'dev'
is created
INFO: 2025-01-08 16:31:33: ...getting the
snapshot of Database 'mstr' at this time
INFO: 2025-01-08 16:31:33: ...successfully
took the ACFS snapshot 'dev' of database 'mstr' on '/data'
INFO: 2025-01-08 16:31:37: ...setting up
storage for SNAP Database 'dev'
INFO: 2025-01-08 16:31:50: Entering into
SNAP database creation phase 2
INFO: 2025-01-08 16:31:50: ...creating
controlfile for database 'dev'
INFO: 2025-01-08 16:32:23: ...recovering
the database: dev, snapshot time : '2025-01-08:16:31:33', until
'change:39241811117184'
INFO: 2025-01-08 16:32:34: ...opening the
database with resetlogs
INFO: 2025-01-08 16:32:49: ...setting the
temporary tablespace for database 'dev'
INFO: 2025-01-08 16:35:06: ...creating
spfile for 'dev'
INFO: 2025-01-08 16:35:08: ...Creating
pfile for 'dev'
INFO: 2025-01-08 16:35:10: Creating
password file for 'dev'
INFO: 2025-01-08 16:35:10: Entering into
SNAP database creation phase 3
INFO: 2025-01-08 16:35:19: ...starting
database 'dev'
INFO: 2025-01-08 16:35:40: ...successfully
started the database
INFO: 2025-01-08 16:35:42: ...setting RMAN
SNAPSHOT control file
INFO: 2025-01-08 16:35:47: ...disabling the
external references in the database 'dev' inherited from 'mstr'
------------------------------------------------------------------------------
Run on the database 'dev' the SQL script:
'/u01/app/oracle/product/19.0.0.0/dbhome_1/enable_external_refs_dev_CN5r.sql'
to enable these external references.
Also need to restart the database after
running the SQL script.
------------------------------------------------------------------------------
INFO: 2025-01-08 16:37:12: Enabling block
change tracking for database 'dev'
INFO: 2025-01-08 16:37:16: Setup ACFS
dependency
SUCCESS: 2025-01-08 16:37:20: Snapshot database 'dev' created successfully
INFO: 2025-01-08 16:37:20: Starting
database 'dev'
SUCCESS: 2025-01-08 16:37:21: Successfully
started clone database 'dev'
Now emphasize in below output where master snap has size of 5.35 TB where as snapshot ccbdev is consuming only 514 GB
acfsutil snap info /ccbdata
snapshot name: ccbmstr
snapshot location: /data/.ACFS/snaps/ccbmstr
RO snapshot or RW snapshot: RW
parent name: /data
snapshot creation time: Wed Jan 8 14:52:59 2025
file entry table allocation: 8781824 ( 8.38 MB )
storage added to snapshot: 5885571432448 ( 5.35 TB )
snapshot name: ccbdev
snapshot location: /data/.ACFS/snaps/ccbdev
RO snapshot or RW snapshot: RW
parent name: ccbmstr
snapshot creation time: Wed Jan 8 16:31:33 2025
file entry table allocation: 8781824 ( 8.38 MB )
storage added to snapshot: 551938048000 ( 514.03 GB )
number of snapshots: 2
kilosnap state: ENABLED
snapshot space usage: 6440485769216 ( 5.86 TB )
df -h /data
Filesystem Size Used Avail Use% Mounted on
/dev/asm/data-132 9.0T 5.9T 3.1T 66% /data
Please mind that mstr DB size is around 5 TB so ideally if we clone another database out of it /data will run out of space but due to snapshot mechanism it consumes only 514 GB.
I hope this will work as a good strater if you have similar problem in your company.
Happy learning...
