7.7.1.5 ALTER GRIDDISK
Purpose
The ALTER GRIDDISK
command changes the attributes of all grid disks or specified grid disks.
Caution:
Before changing the name of a grid disk that belongs to an Oracle ASM disk group, ensure that the Oracle ASM disk group is offline.Syntax
ALTER GRIDDISK { ALL [[ CAPACITYOPTIMIZED | PERFORMANCEOPTIMIZED ] FLASHDISK | HARDDISK ] | gdisk_name1 [,gdisk_name2] ... }
{ [ attribute_filters ] [ ACTIVE | INACTIVE ] [ FLUSH [NOWAIT] | CANCEL FLUSH ] } |
attribute_name = attribute_value [, attribute_name = attribute_value] ...
[ attribute_filters ] [NOWAIT] }
Command Options
-
Starting with Oracle Exadata System Software release 24.1.0, you can optionally specify
CAPACITYOPTIMIZED
orPERFORMANCEOPTIMIZED
beforeFLASHDISK
to alter grid disks on cell disks associated with the specified flash media type.If you do not fully specify the flash media type,
ALL FLASHDISK
is equivalent toALL CAPACITYOPTIMIZED FLASHDISK
on Extreme Flash (EF) storage servers containing capacity-optimized flash devices. On all other storage servers,ALL FLASHDISK
is equivalent toALL PERFORMANCEOPTIMIZED FLASHDISK
. -
If the
ALL
option is specified with a media type qualifier (FLASHDISK
orHARDDISK
), the command only alters grid disks on cell disks associated with the specified media type.Starting with Oracle Exadata System Software release 24.1.0, if you specify the
ALL
option without a media type qualifier (FLASHDISK
orHARDDISK
), then the command alters grid disks on the cell disks associated with the primary storage media on the storage server. Specifically:-
On Extreme Flash (EF) storage servers containing capacity-optimized flash devices,
ALL
with no media type qualifier is equivalent toALL CAPACITYOPTIMIZED FLASHDISK
. -
On Extreme Flash (EF) storage servers containing only performance-optimized flash devices,
ALL
with no media type qualifier is equivalent toALL PERFORMANCEOPTIMIZED FLASHDISK
. -
On all storage servers containing hard disk drives (HDDs),
ALL
with no media type qualifier is equivalent toALL HARDDISK
.
Before Oracle Exadata System Software release 24.1.0, if the
ALL
option is specified without a media type qualifier, the command alters all matching grid disks regardless of media type. -
-
The
ACTIVE
option notifies CELLSRV to accept I/O as normal for the specified grid disks. The grid disks are visible to the database clients. -
The
INACTIVE
option makes the grid disks visible to the cell administrator, but not visible to the database clients. CELLSRV treats the grid disks as if they were offline. This mode allows management operations on the grid disks. You can do upgrading and testing on the grid disks before making the grid disks visible to database users. This functionality is similar to starting up a database inRESTRICTED
mode.Note:
If the grid disk is used by Oracle ASM and is madeINACTIVE
when currently in use by a database client, Oracle ASM takes the corresponding Oracle ASM disk offline when I/Os to the disk fail. To make the disk usable again, make the grid diskACTIVE
in the cell, and then bring the corresponding Oracle ASM disk back online in Oracle ASM. -
The
FLUSH
option synchronizes dirty data from the flash cache to the grid disks. Dirty data is data that has not been synchronized with the grid disk.Synchronization of dirty data can be a lengthy process, depending on the number of bytes to be synchronized. Use the following command to check the progress:
LIST GRIDDISK ATTRIBUTES name, flushstatus
-
The
CANCEL FLUSH
option terminates an earlier flush operation. -
The
NOWAIT
option allows theALTER
command to complete while a resize or flush operation continues, for example: -
Starting with Oracle Exadata System Software release 20.1.0, the
ALTER GRIDDISK
command accepts aWHERE
clause, which allows for a specific subset of grid disks to be altered. For example, if you have two sets of grid disks, one forDATA
and the other forRECO
, you can use theWHERE
clause to resize the grid disks from one disk group only, for example:ALTER GRIDDISK size=5T WHERE name like 'RECO.*'
You can use the
WHERE
clause with either a list of grid disks or with theALL {FLASHDISK|HARDDISK}
option. If you use theWHERE
clause and do not specify either a list of grid disks or theALL {FLASHDISK|HARDDISK}
option, then theWHERE
clause acts against all disks. Some examples of this syntax are:ALTER GRIDDISK WHERE name like 'DATA.*' INACTIVE ALTER GRIDDISK ALL FLASHDISK FLUSH NOWAIT
Usage Notes
The attributes that can be changed with the ALTER GRIDDISK
command are shown as modifiable
in Example 7-104.
-
The length of a grid disk name is limited to 30 characters.
-
The
FLUSH
option stops new data from being cached on the specified grid disks until CELLSRV restarts, or the flush operation is canceled. -
The
FLUSH
option is valid for write back disks, not write through disks. -
The
size
attribute can be specified to expand or reduce space allocated to a grid disk.The
size
attribute is specified as a number in bytes, unless the suffixM
(megabytes) orG
(gigabytes) is included with the number value. Grid disk space is allocated in 16 MB units, referred to as allocation units. The actual size allocated is the size of the largest multiple of allocation units less than or equal to the specified size. The minimum value is 16 MB. Values less than 16 MB are rounded up to 16 MB.If the grid disk is used by Oracle ASM, the corresponding Oracle ASM disk must be resized separately.
-
A grid disk should not be renamed when the grid disk is being accessed.
If you try to rename a grid disk when it is being accessed, then the operation fails. If the grid disk is used by Oracle ASM, you can make the grid disk inactive or dismount the Oracle ASM disk group to stop access to the grid disk before renaming it.
-
When an interleaved grid disk is resized, the contents of the grid disk are moved to achieve the interleaved space allocation across the cell disk. The resizing operation can take a few minutes. You can choose to have the data movement proceed as a background process by using the
NOWAIT
option. Use theLIST GRIDDISK
command to check the status.Note:
Interleaved grid disks are deprecated in Oracle Exadata System Software release 19.1.0. -
The
cachingPolicy
attribute specifies the flash caching policy for the grid disk.Flash cache is effectively disabled for database files located in a disk group composed of grid disks having
cachingPolicy
set tonone
. You may choose this because:-
You want specific database files persisted directly to disk instead of utilizing flash cache.
-
You want to dedicate flash cache resources to objects in other database files.
Use the following commands to set the
cachingPolicy
attribute tonone
:ALTER GRIDDISK grid_disk_name CACHINGPOLICY="none" ALTER GRIDDISK grid_disk_name FLUSH -- Wait for the FLUSH to complete. ALTER GRIDDISK grid_disk_name CANCEL FLUSH
To re-enable caching on the grid disk:
ALTER GRIDDISK grid_disk_name CACHINGPOLICY="default"
-
Example 7-37 Altering Grid Disk Attributes
This example shows the ALTER
command with the GRIDDISK
object.
CellCLI> ALTER GRIDDISK data1_CD_01_cell01, data2_CD_01_cell01
comment = "This grid disk is on cell01"
CellCLI> ALTER GRIDDISK ALL INACTIVE
Related Topics
Parent topic: ALTER