jason arneil solutions architect
DESCRIPTION
Jason Arneil Solutions Architect. What’s New with 12c ASM . Agenda. Consolidation. jarneil.wordpress.com. @ jarneil. Customers. ASM. ASM – A recap. ASM Protection. Extents & Redundancy. Agenda. Whats New?. Disk Management. Physical Metadata Replication. Improved Availability. - PowerPoint PPT PresentationTRANSCRIPT
Slide 1
Jason ArneilSolutions ArchitectWhats New with 12c ASM Oracle EMEA Database Partner of the Year
Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
In this presentation Im going to take a look at the new features of ASM available with the 12c release.
How many of you use ASM for your databases?
1AgendaConsolidation
Oracle EMEA Database Partner of the Year
Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
So what am I going to talk about today
RECAP
NEW FEATURES
DEMO2
jarneil.wordpress.com@jarneilOracle EMEA Database Partner of the Year
Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
My name is Jason Arneil
Been in IT for around 15 years
SA/DBA
Written quite a few blog articles
also on twitter
now an oracle AceCustomers
Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
Work in the Engineered Systems Team at e-dba
Team is 100% focused on the e-dba Exadata customers
e-dba are on Oracle platinum partner
We have our own Exadata x3-2 and exalytics boxes available for POC
4
ASMOracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
When Automatic Storage Management (ASM) was introduced in 10gR1
ASM was designed as a purpose-built host based volume management and file system that is integrated with the Oracle database.
It is built on stripping and mirroring methodology (SAME)
ASM is built on the Oracle instance architecture5ASM A recap
Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
Just like the database has a storage hierarchy
going from the data block upto the tablespace
There is a similar hierarchy in ASM
From the DBAs view, ASM exposes Disk Groups you can think of the DISKGROUP as like a filesystem
and it is in a diskgroup that tablespaces are created
These Disk Groups consists of ASM disks and files that are stripped across all the disks in a Disk Group.
Every ASM disk is divided into allocation units (AU).
An AU is the fundamental unit of allocation within a disk group.
A file extent consists of one or more AU. An ASM file consists of one or more file extents.
6ASM Protection
Oracle EMEA Database Partner of the Year
Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
3 LEVELS of ASM PROTECTION for your data
EXTERNAL lets the storage array take care of it
NORMAL write 2 copies of your extents
HIGH write 3 copies of your extents
7Extents & RedundancyOracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
Every ASM disk is divided into allocation units (AU).
An AU is the fundamental unit of allocation within a disk group.
A file extent consists of one or more AU. An ASM file consists of one or more file extents.
8AgendaWhats New?Oracle EMEA Database Partner of the Year
Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
9Disk ManagementPhysical Metadata ReplicationImproved AvailabilityOracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
Physical Metadata Replication
Oracle ASM now replicates physically addressed metadata
like disk header, free space blocks and allocation table
This is tracked with a diskgroup attribute PHYS_META_REPLICATED
turned on when ASM compatibility of the diskgroup is advanced to 12.1
This ensures ASM is more resilient to bad disk sectors and external corruptions10Disk ManagementConcurrent RebalanceImproved AvailabilityOracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
In previous versions, an ASM instance could only perform one rebalance operation at a time on the same instance.
If two disk group rebalance requests (for two different disk groups) were issued within the same ASM instance, then the second rebalance operation would be queued up behind the first request
With Oracle Database 12c, a single ASM instance can now perform multiple rebalance operations concurrently11Disk ManagementFile Priority RebalanceImproved Availability Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
Upon a rebalance due to a failed disk drive ASM will now restore the redundancy of the data based on the criticality of the files.
i.e. control files and redo logs will have their redundancy restored first.12Disk ManagementDisk ScrubbingImproved Availability Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
Upon a rebalance due to a failed disk drive ASM will now restore the redundancy of the data based on the criticality of the files.
i.e. control files and redo logs will have their redundancy restored first.
Can set the CONTENT.CHECK attribute on a diskgroup to ensure a rebalance will perform this logical content checking13Disk ManagementFast Disk Resync CheckpointsImproved availability Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
When a disk drive suffers a transient failure temporarily becoming unavailable a rebalance does not have to occur immeidately
Instead the changes that would have been written to this unavailable disk are tracked
and when the disk becomes avaialble again those changes can be synced to the disk
While this was available in 11g, if that sync got interrupted it would have to restart from the beginning
Now in 12c there are checkpoints so and interruption will not mean having to repeat lots of changes already done
Also possibility to set a power limit for the resync operation
14Disk ManagementFailure Group Repair TimerImproved availability Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
In addition to a repair timer being set for an individual disk
Can now be set for an entire failure group by default this is 24h
the idea being that a failure of entire failure group is likely to be transient therefore dont do a big rebalance
however with normal redundancy you have a bigger exposure to data loss if another disk fails
15I/O PerformanceEven ReadImproved PerformanceOracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
Default behaviour of ASM has been to only read primary extents
Even Read ensures the extent that resides on the least loaded device will be read
Even Read is enabled by default
This should improve the performance of I/O bound systems.
16ScalabilityIncreased Number of DiskgroupsImproved ScalabilityOracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
number of diskgroups supported has gone from 63 to 51117EstimatingExplain WorkImproved ManageabilityOracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
18Password FilesPassword Files in ASMImproved ManageabilityOracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
Previously almost all database and ASM related files could be stored in ASM.
A key exception was the password file
both the ASM and database password files could not be stored in ASM
For 12c the default location of the password file is ASM
Note that the compatible.asm disk group attribute must be set to 12.119Flex ASM
Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
So currently
Tight 1:1 binding of ASM to cluster host
Loss of an ASM instance means loss of all databases on that server
In a cloud environment (PaaS) this less than desirable
20Flex ASMCurrent scenarioASM Cluster Pool of StorageNode2
Disk Group BDisk Group ANode3Node5Node4
Shared Disk Groups
Wide File Striping
One to One Mapping of ASM Instances to Servers
Node1
ASM InstanceDatabase InstanceASM Disk
Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
If an ASM instance on a node crashes
ALL instances on that node will crash
This is not good, particularly in a consolidated environment where many, many instances could be impacted21Flex ASM
Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
Now with 12c You dont need an ASM instance running on each and every node!
DB Instances can use an ASM instance running on another node
By default you have 3 ASM instances for a cluster this is controlled via the ASM cardinality
If an node running one of the ASM instances fails an ASM instance will be restarted on another node
Instances running on a node wont crash if ASM on that node crashes.22Flex ASMWith Flex ASMASM Cluster Pool of StorageDisk Group BDisk Group AShared Disk Groups
Wide File Striping
Databases share ASM instances
ASM InstanceDatabase InstanceASM Disk
Node5Node4
Node3
Node2
Node1
Node5
Node5 runs as ASM Client to Node4 Node1 runs as ASM Client to Node2 Node1 runs as ASM Client to Node4 Node2 runs as ASM Client to Node3 Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
Flex ASM
Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
12c provides for a dedicated network for ASM traffic
Remember its metadata (files extent maps etc) etc NOT all IO traffic
DATABASES do NOT perform their I/O via the ASM instance, once they have the metadata they talk to the storage direct.
Can use the Clusterware private interconnect
24Flex ASM3
Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
25Flex ASMClassic ModeMixed Mode12c ModeOracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year
26Q & A
Oracle Partner of the year 2010 & 2012 +44 (0) 844 811 [email protected] RedStack Technology CompanyOracle EMEA Database Partner of the Year