Home / NetApp Clustered ONTAP / NetApp – Clustered DATA ONTAP – Storage Aggregate – Part 9

NetApp – Clustered DATA ONTAP – Storage Aggregate – Part 9

Storage systems should provide the fault tolerance if any  disk failures occurs in disk-shelf’s. NetApp uses the RAID-DP technology to provide the fault tolerance. A RAID group includes several disks that are linked together in a storage system. Although there are different implementations of RAID, Data ONTAP supports only RAID 4 and RAID-DP. Data ONTAP classifies disks as one of four types for RAID: data, hot spare, parity, or double-parity. The RAID disk  type is determined by how RAID is using a disk.

 

Data disk A data disk is part of a RAID group and stores data on behalf of the client.
Hot spare disk  A hot spare disk does not hold usable data but is available to be added to a RAID group in an aggregate. Any functioning disk that is not assigned to an aggregate, but is assigned to a system, functions as a hot spare disk.
Parity disk A parity disk stores data reconstruction within a RAID group.
Double-parity disk A double-parity disk stores double-parity information within RAID groups if NetApp RAID  software, double-parity (RAID-DP) is enabled.

 

RAID-4 :

RAID-4 Protects the data from single disk failure. It requires minimum three disk to configure.  (2 – Data disks & 1 – Parity disk)

Using RAID 4, if one disk block goes bad, the parity disk in that disk’s RAID group is used to recalculate the data in the  failed block, and then the block is mapped to a new location on the disk. If an entire disk fails, the parity disk prevents any data from being lost. When the failed disk is replaced, the parity disk is used to automatically recalculate its contents. This is sometimes referred to as row parity.

NetApp RAID 4
NetApp RAID 4

 

RAID-DP:

RAID-DP technology protects against data loss due to a double-disk failure within a RAID group.

Each RAID-DP group contains the following:

  • Three data disks
  • One parity disk
  • One double-parity disk

RAID-DP employs the traditional RAID 4 horizontal row parity. However, in RAID-DP, a diagonal parity stripe is
calculated and committed to the disks when the row parity is written.

NetApp RAID-DP
NetApp RAID-DP

 

 

RAID GROUP MAXIMUMS:

Here is the RAID group Maximums for NetApp Storage systems. RAID groups can include anywhere from 3 to 28 disks, depending on the platform and RAID type. For best performance and reliability, NetApp recommends using the default RAID group size.

NetApp RAID Maximums

NetApp RAID Maximums

 

Aggregates: 

An aggregate is virtual layer of  RAID groups. RAID is built using the bunch of physical disks . Aggregates can use RAID-4 raid groups or RAID-DP raid groups. These aggregates can be taken over by the HA partner  if the controller fails. Aggregates can be grown up by adding the physical disks to it (In the back-end , it will form the RAID groups).  There are two type of aggregates possible in NetApp.

  • 32-Bit Aggregate
  • 64-Bit Aggregate

At any time, you can convert the 32-Bit Aggregate to 64-Bit aggregate without any downtime. 64-Bit aggregate supports more than 16TB of storage.

 

Let’s see the storage aggregate commands.

1.Login  to the NetApp Cluster’s  LIF.

2.List the available storage aggregates on the system.

NetUA::> storage aggregate show
Aggregate     Size Available Used% State   #Vols  Nodes            RAID Status
--------- -------- --------- ----- ------- ------ ---------------- ------------
aggr0_01     900MB   43.54MB   95% online       1 NetUA-01         raid_dp,
                                                                   normal
aggr0_02     900MB   43.54MB   95% online       1 NetUA-02         raid_dp,
                                                                   normal
2 entries were displayed.

NetUA::>

 

3.List the Provisioned volumes with aggregate names . vol0 resides on aggregate “aggr0_01”.

NetUA::> volume show
Vserver   Volume       Aggregate    State      Type       Size  Available Used%
--------- ------------ ------------ ---------- ---- ---------- ---------- -----
NetUA-01  vol0         aggr0_01     online     RW      851.5MB    431.0MB   49%
NetUA-02  vol0         aggr0_02     online     RW      851.5MB    435.9MB   48%
2 entries were displayed.

NetUA::>

 

4.List the available disks on Node NetUA-01. Here you can see that what are the disks are part of aggregate.

NetUA::> storage disk show -owner NetUA-01
                     Usable           Container
Disk                   Size Shelf Bay Type        Position   Aggregate Owner
---------------- ---------- ----- --- ----------- ---------- --------- --------
NetUA-01:v4.16       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v4.17       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v4.18       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v4.19       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v4.20       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v4.21       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v4.22       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v4.24       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v4.25       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v4.26       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v4.27       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v4.28       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v4.29       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v4.32       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v5.16       1020MB     -   - aggregate   dparity    aggr0_01  NetUA-01
NetUA-01:v5.17       1020MB     -   - aggregate   parity     aggr0_01  NetUA-01
NetUA-01:v5.18       1020MB     -   - aggregate   data       aggr0_01  NetUA-01
NetUA-01:v5.19       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v5.20       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v5.21       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v5.22       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v5.24       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v5.25       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v5.26       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v5.27       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v5.28       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v5.29       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v5.32       1020MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.16      520.5MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.17      520.5MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.18      520.5MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.19      520.5MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.20      520.5MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.21      520.5MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.22      520.5MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.24      520.5MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.25      520.5MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.26      520.5MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.27      520.5MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.28      520.5MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.29      520.5MB     -   - spare       present    -         NetUA-01
NetUA-01:v6.32      520.5MB     -   - spare       present    -         NetUA-01
42 entries were displayed.

NetUA::>

 

5.Let’s look at the specific aggregate’s configuration.

NetUA::> stor aggr show -aggr aggr0_01
  (storage aggregate show)

                                         Aggregate: aggr0_01
                                    Checksum Style: block
                                   Number Of Disks: 3
                                             Nodes: NetUA-01
                                             Disks: NetUA-01:v5.16,
                                                    NetUA-01:v5.17,
                                                    NetUA-01:v5.18
                           Free Space Reallocation: off
                                         HA Policy: cfo
                Space Reserved for Snapshot Copies: -
                                    Hybrid Enabled: false
                                    Available Size: 43.49MB
                                  Checksum Enabled: true
                                   Checksum Status: active
                                  Has Mroot Volume: true
                     Has Partner Node Mroot Volume: false
                                           Home ID: 4079432749
                                         Home Name: NetUA-01
                           Total Hybrid Cache Size: 0B
                                            Hybrid: false
                                      Inconsistent: false
                                 Is Aggregate Home: true
                                     Max RAID Size: 16
       Flash Pool SSD Tier Maximum RAID Group Size: -
                                          Owner ID: 4079432749
                                        Owner Name: NetUA-01
                                   Used Percentage: 95%
                                            Plexes: /aggr0_01/plex0
                                       RAID Groups: /aggr0_01/plex0/rg0 (block)
                                       RAID Status: raid_dp, normal
                                         RAID Type: raid_dp
                                           Is Root: true
      Space Used by Metadata for Volume Efficiency: 0B
                                              Size: 900MB
                                             State: online
                                         Used Size: 856.5MB
                                 Number Of Volumes: 1
                                      Volume Style: flex

NetUA::>

aggr0_01 is configured using “/aggr0_01/plex0/rg0” .

 

Let’s have a close look of rg0.

NetUA::> system node run -node NetUA-01 aggr status aggr0_01 -r

Aggregate aggr0_01 (online, raid_dp) (block checksums)
  Plex /aggr0_01/plex0 (online, normal, active)
    RAID group /aggr0_01/plex0/rg0 (normal, block checksums)

      RAID Disk Device  HA  SHELF BAY CHAN Pool Type  RPM  Used (MB/blks)    Phys (MB/blks)
      --------- ------  ------------- ---- ---- ---- ----- --------------    --------------
      dparity   v5.16   v5    ?   ?   FC:B   -  FCAL 15000 1020/2089984      1027/2104448
      parity    v5.17   v5    ?   ?   FC:B   -  FCAL 15000 1020/2089984      1027/2104448
      data      v5.18   v5    ?   ?   FC:B   -  FCAL 15000 1020/2089984      1027/2104448

NetUA::>

Aggregate Name = aggr0_01
Node Name = NetUA-01

We have explored more things about existing aggregate. Let’s see that how to create the new aggregate.

 

Creating the New Aggregate:

1. To create the aggregate with name “NetUA01_aggr1” on node “NetUA-01” with 5 FCAL disks , use the following command.

NetUA::> stor aggr create -aggr NetUA01_aggr1 -node NetUA-01 -diskcount 5 -disktype FCAL
  (storage aggregate create)
[Job 80] Job succeeded: DONE

NetUA::>

 

2. Verify the newly created aggregate.

NetUA::> storage aggregate show
Aggregate     Size Available Used% State   #Vols  Nodes            RAID Status
--------- -------- --------- ----- ------- ------ ---------------- ------------
NetUA01_aggr1
            2.64GB    2.64GB    0% online       0 NetUA-01         raid_dp,
                                                                   normal
aggr0_01     900MB   39.08MB   96% online       1 NetUA-01         raid_dp,
                                                                   normal
aggr0_02     900MB   43.54MB   95% online       1 NetUA-02         raid_dp,
                                                                   normal
3 entries were displayed.

NetUA::>

 

Adding new disks to Aggregate:

1.Add two disks to the aggregate “NetUA01_aggr1” .

NetUA::> aggr add-disks -aggr NetUA01_aggr1 -disktype FCAL -diskcount 2

 

2.Verify the storage size.

NetUA::>  storage aggregate show
Aggregate     Size Available Used% State   #Vols  Nodes            RAID Status
--------- -------- --------- ----- ------- ------ ---------------- ------------
NetUA01_aggr1
            4.39GB    4.39GB    0% online       0 NetUA-01         raid_dp,
                                                                   normal
aggr0_01     900MB   43.51MB   95% online       1 NetUA-01         raid_dp,
                                                                   normal
aggr0_02     900MB   43.54MB   95% online       1 NetUA-02         raid_dp,
                                                                   normal
3 entries were displayed.

 

3. Verify the newly added disks.

NetUA::> aggr show -aggr NetUA01_aggr1

Aggregate: NetUA01_aggr1
Checksum Style: block
Number Of Disks: 7
Nodes: NetUA-01
Disks: NetUA-01:v4.16,
NetUA-01:v5.19,
NetUA-01:v4.17,
NetUA-01:v5.20,
NetUA-01:v4.18,
NetUA-01:v5.21,
NetUA-01:v4.19
Free Space Reallocation: off
HA Policy: sfo
Space Reserved for Snapshot Copies: -
Hybrid Enabled: false
Available Size: 4.39GB
Checksum Enabled: true
Checksum Status: active
Has Mroot Volume: false
Has Partner Node Mroot Volume: false
Home ID: 4079432749
Home Name: NetUA-01
Total Hybrid Cache Size: 0B
Hybrid: false
Inconsistent: false
Is Aggregate Home: true
Max RAID Size: 16
Flash Pool SSD Tier Maximum RAID Group Size: -
Owner ID: 4079432749
Owner Name: NetUA-01
Used Percentage: 0%
Plexes: /NetUA01_aggr1/plex0
RAID Groups: /NetUA01_aggr1/plex0/rg0 (block)
RAID Status: raid_dp, normal
RAID Type: raid_dp
Is Root: false
Space Used by Metadata for Volume Efficiency: 0B
Size: 4.39GB
State: online
Used Size: 180KB
Number Of Volumes: 0
Volume Style: flex

NetUA::>

 

4. Check the RAID status.

NetUA::> system node run -node NetUA-01 aggr status NetUA01_aggr1 -r

Aggregate NetUA01_aggr1 (online, raid_dp) (block checksums)
  Plex /NetUA01_aggr1/plex0 (online, normal, active)
    RAID group /NetUA01_aggr1/plex0/rg0 (normal, block checksums)

      RAID Disk Device  HA  SHELF BAY CHAN Pool Type  RPM  Used (MB/blks)    Phys (MB/blks)
      --------- ------  ------------- ---- ---- ---- ----- --------------    --------------
      dparity   v4.16   v4    ?   ?   FC:B   -  FCAL 15000 1020/2089984      1027/2104448
      parity    v5.19   v5    ?   ?   FC:B   -  FCAL 15000 1020/2089984      1027/2104448
      data      v4.17   v4    ?   ?   FC:B   -  FCAL 15000 1020/2089984      1027/2104448
      data      v5.20   v5    ?   ?   FC:B   -  FCAL 15000 1020/2089984      1027/2104448
      data      v4.18   v4    ?   ?   FC:B   -  FCAL 15000 1020/2089984      1027/2104448
      data      v5.21   v5    ?   ?   FC:B   -  FCAL 15000 1020/2089984      1027/2104448
      data      v4.19   v4    ?   ?   FC:B   -  FCAL 15000 1020/2089984      1027/2104448

NetUA::>

 

We have just created the aggregate layer. In the upcoming articles,  we will see that how to create the vserver and flex volumes.

 

Hope this article is informative to you.

VMTURBO-CLOUD-CAPACITY

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