SOLARIS VOLUME MANAGERSOLARIS VOLUME MANAGER

SVMSVM

►Each disk slice has its own physical and logical Each disk slice has its own physical and logical device.device.

►File system cannot span more than one disk sliceFile system cannot span more than one disk slice►The maximum size of file system is limited to The maximum size of file system is limited to

the size of the single disk.the size of the single disk.►Here we can create the virtual volumes. it means Here we can create the virtual volumes. it means

disk partitions are grouped across several disk to disk partitions are grouped across several disk to appear as single volume to operating system.appear as single volume to operating system.

SVMSVM

RAID concept was introduced at the RAID concept was introduced at the university of California at Berkeley in university of California at Berkeley in

1987 by David Patterson, Garth 1987 by David Patterson, Garth Gibson and Randy Katz.Gibson and Randy Katz.

SoftwareSoftware

►Sun 8 - Solatice disk suiteSun 8 - Solatice disk suite►Sun 9, Sun 10 - SVMSun 9, Sun 10 - SVM►Third party tool – VeritasThird party tool – Veritas

RAID STANDARDSRAID STANDARDS► RAID 0 - Striping or ConcatenationRAID 0 - Striping or Concatenation► RAID 1 - MirroringRAID 1 - Mirroring► RAID 0+1 - Striping with MirroringRAID 0+1 - Striping with Mirroring► RAID 1+0 - Mirroring with StripingRAID 1+0 - Mirroring with Striping► RAID 2 - Hamming code correctionRAID 2 - Hamming code correction► RAID 3 - Striping with dedicated party RAID 3 - Striping with dedicated party

disk disk ► RAID 4 - Independent reads and writesRAID 4 - Independent reads and writes► RAID 5 - Striping with distributed parityRAID 5 - Striping with distributed parity► RAID 6 - RAID 5 with second parity RAID 6 - RAID 5 with second parity

calculationcalculation

►RAID levels 2,3,4 and 6 not available RAID levels 2,3,4 and 6 not available with Solaris volume manager software. with Solaris volume manager software. These RAID levels are not commonly These RAID levels are not commonly implemented in commercial implemented in commercial applications. Raid 0+1 and RAID 1+0 applications. Raid 0+1 and RAID 1+0 are not RAID levels. But are are not RAID levels. But are abstrations composed of more than abstrations composed of more than one RAID levels.one RAID levels.

Features of RAIDFeatures of RAID

►Large disk supportLarge disk support►AvailablityAvailablity►PerformancePerformance

Concatenation (RAID 0)Concatenation (RAID 0)

Partition10 mb

Partition10 mb

Svm software Volume20mb

Disk concatenationDisk concatenation

► It combines multiple partition to create It combines multiple partition to create a large volume.a large volume.

►The Data is Spread over multiple disk The Data is Spread over multiple disk and multiple partition.( one by one)and multiple partition.( one by one)

►No redundancyNo redundancy► It can contains disks slices of different It can contains disks slices of different

sizes because they are merely joined sizes because they are merely joined together.together.

Striping (RAID 0)Striping (RAID 0)

Interlace1interlace3

10 mb

Interlace2interlace4

10 mb

Svm software Volume20mb

Disk StripingDisk Striping

►A feature used to increase read and A feature used to increase read and write performance by spreading data write performance by spreading data requests over multiple componentsrequests over multiple components

►The component making strip must all The component making strip must all be same size.be same size.

Mirror (RAID 1)Mirror (RAID 1)

Data1Data210 mb

Data1Data210 mb

Svm software Volume10mb

Disk mirroringDisk mirroring

►A feature used to guard against A feature used to guard against failure.failure.

►Any file system can be mirrored, Any file system can be mirrored, including root, swap and usr.including root, swap and usr.

►Required twice disk same capacity.Required twice disk same capacity.

Striping with distributed parity Striping with distributed parity (RAID 5)(RAID 5)

Interlace1Interlace4Parity 2,3

10 mb

Interlace2Interlace 5Parity 1,3

10 mb

Interlace 3Interlace 6Parity 1,2

10 mb

RAID 5D2

20% mb

►Create RAID 5 volume with a minimum Create RAID 5 volume with a minimum of three slicesof three slices

►Use same disk sizeUse same disk size►The pattern of writing data and parity The pattern of writing data and parity

results in both data and parity spread results in both data and parity spread across all the disks in the RAID 5 across all the disks in the RAID 5 volumevolume

►Parity protect against a single disk Parity protect against a single disk failure.failure.

RAID 0+1RAID 0+1

RAID 1+0RAID 1+0

DisksetDisksetA grouping of two hosts and A grouping of two hosts and disk drives in which all the disk drives in which all the

drivers are accessible by both drivers are accessible by both hosts.hosts.

This feature provides facilities This feature provides facilities for hosts to share disks in high for hosts to share disks in high

availabilty environmentavailabilty environment

FEATURE

RAID 0 CONCATENATION

RAID O STRIPE RAID 1 RAID 5

Reduntant data No No Yes Yes

Improve read performance No Yes

depends on underlying device Yes

improve write performance No Yes No No

Factors RAID 1 RAID 5 NON-Redundant

writes opertions Faster Slower Neutral

Random read Slower Faster Neutral

Hardware cost Highest Higher Lowest

performance during failure Best Poor Data loss

►VolumeVolume A volume or metadevice , is a A volume or metadevice , is a

group of physical slices that appear to group of physical slices that appear to the system as a single, logical device. the system as a single, logical device. A volume is used to increase storage A volume is used to increase storage capacity and increase data availability capacity and increase data availability solaris 10 svm can support to 8192 solaris 10 svm can support to 8192 logical volumes per disk set, but logical volumes per disk set, but default support 128 logical volumes, default support 128 logical volumes, namely d0 to d127.namely d0 to d127.

► State databaseState database A state database is database that A state database is database that

stores information about the state of the svm stores information about the state of the svm configuration.Each state database is a collection of configuration.Each state database is a collection of multiple, replicated datebase copies. Each database multiple, replicated datebase copies. Each database copy is referred to as a state database repilca.svm copy is referred to as a state database repilca.svm cannot operate untill you have create the state cannot operate untill you have create the state datebase and the repilcas. You should create at datebase and the repilcas. You should create at least three statedatebase repilcas when using svm least three statedatebase repilcas when using svm because the validation process requires a majority.because the validation process requires a majority.(half+1)of the state database to be consistent with (half+1)of the state database to be consistent with each other before the system will start up each other before the system will start up ccorrectly.ccorrectly.

►Soft partitionSoft partition

A soft partition is a means A soft partition is a means of dividing a disk or volume into as of dividing a disk or volume into as many partition as needed. Overcoming many partition as needed. Overcoming the current limitation of eight. This is the current limitation of eight. This is done by creating logical partitions with done by creating logical partitions with physical slices or logical volumes.physical slices or logical volumes.

►Desk setDesk set A diskset is a set of drivers A diskset is a set of drivers

containing state datebase repilcas, containing state datebase repilcas, volume , and hotspares that can be volume , and hotspares that can be shared exclusively, but not at the shared exclusively, but not at the same time , by multiple hosts. If one same time , by multiple hosts. If one host fails, another host can take over host fails, another host can take over the failed hosts disk set, this type of the failed hosts disk set, this type of fallover configuration is reffered to as fallover configuration is reffered to as a clustered environmenta clustered environment

►Hot spareHot spare

A hot spare is a slice that is A hot spare is a slice that is reserved for use in case of a slice reserved for use in case of a slice failure in another volume , such as a failure in another volume , such as a submirror or RAID 5 metadevice. It is submirror or RAID 5 metadevice. It is used to increase data availablity.used to increase data availablity.

►Hot spare spoolHot spare spool

►A hot spare poll is a collection of hot A hot spare poll is a collection of hot spares. A hot spare poll can be spares. A hot spare poll can be used to provide a number of hot used to provide a number of hot spares for spares for specific volumes spares for spares for specific volumes or metadevices.or metadevices.

►metaclear metaclear

Used to delete metadevices Used to delete metadevices and can also be used to delete hot and can also be used to delete hot spare spool.spare spool.

Metadb Metadb

used to create and delete the used to create and delete the state datebase and its replicas.state datebase and its replicas.