DROP CELLDISK

7.7.6.3 DROP CELLDISK

Purpose

The DROP CELLDISK command removes all or the named cell disks from the cell.

This command is necessary if a cell disk fails, or it is replaced by a newer model.

Before dropping a cell disk, you should remove the corresponding grid disks from any associated Oracle ASM disk groups or Exascale storage pools and then drop the grid disks.

Syntax

DROP CELLDISK { ALL [[ CAPACITYOPTIMIZED | PERFORMANCEOPTIMIZED ] FLASHDISK | HARDDISK ] | cdisk_name [, cdisk_name]... }
              [ERASE = value [NOWAIT]] [FORCE]

Usage Notes

If individual cell disks are specified, then the named cell disks (cdisk_name) are dropped.
If the LUN associated with the CELLDISK is flagged as automatically created, then that LUN is deleted along with the cell disk.
If the ALL option is specified, then all the cell disks on the cell are removed.
The FLASHDISK option limits the DROP CELLDISK command to cell disks that are flash disks.

Starting with Oracle Exadata System Software release 24.1.0, you can optionally specify CAPACITYOPTIMIZED or PERFORMANCEOPTIMIZED before FLASHDISK to drop cell disks matching only the specified flash media type.
The HARDDISK option limits the DROP CELLDISK command to cell disks that are hard disks.
If grid disks are configured on the cell disk when DROP CELLDISK is issued, then the FORCE option must be used or an error is reported. The FORCE option causes any grid disks to be dropped first, and then the cell disk is dropped.
If the specified cell disk includes flash cache, and that flash cache is in writeback mode, then the cell disk cannot be dropped.
Starting with Oracle Exadata System Software release 19.1.0, if you specify to erase hard disks or flash disks using 1pass, 3pass, or 7pass method on Oracle Exadata Database Machine X5 or later, Oracle Exadata System Software automatically invokes Secure Eraser to erase the disks. Secure Eraser determines whether or not the disks can be erased using the better and faster cryptographic erasure method. If some of the disks are eligible, then the cryptographic erasure method is used to erase those disks, and the originally requested method (1/3/7 pass) is used on the other disks. This feature is not used on system disks.
The ERASE option erases the content on the disk by overwriting the content. The values are as follows:
- 1pass: One pass, and the content is overwritten with zeros. This option is not applicable for flash drives.
- 3pass: Three passes, and the content is overwritten with set data patterns. This option follows the recommendations from the National Nuclear Security Administration (NNSA). This option is not applicable for flash drives. This value is not available for flash drives.
- 7pass: Seven passes, and the disk is overwritten with set data patterns. This option follows the recommendations from the United States Department of Defense (DOD).
See Table 7-2 for the approximate erasure times for each disk and erasure method.
Use the NOWAIT option with the ERASE option to run the command asynchronously.
When dropping all cell disks using the 1pass or 3pass option, you must drop the flash disks first using the 7pass option, and then drop the cell disks, for example:
```
CellCLI> DROP CELLDISK ALL FLASHDISK ERASE=7pass 
CellCLI> DROP CELLDISK ALL ERASE=1pass 
```

The following table gives a summary of the secure erasure methods used for each device type. Hard drives, flash devices, and internal USBs are securely erased in parallel: the time required to erase one device is the same as that required for erasing multiple devices of the same kind.

Table 7-3 Methods Used to Securely Erase Various Devices

Component	Make or Model	Erasure Method
Hard drive	8 TB hard drives on Oracle Exadata X5 All hard drives on Oracle Exadata X6 or later	Cryptographic erase
Hard drive	All other hard drives	1/3/7-Pass erase
Flash device	Flash devices on Oracle Exadata X5 or later	Cryptographic erase
Flash device	All other flash devices	7-pass erase
M.2 device	Oracle Exadata Database Machine X7-2 or later	Cryptographic erase
Persistent Memory (PMEM) device	Oracle Exadata X8M or X9M	Cryptographic erase

Example 7-127 Examples of Dropping a Cell Disk

CellCLI> DROP CELLDISK CD_03_cell01

CellCLI> DROP CELLDISK CD_02_cell06 FORCE

CellCLI> DROP CELLDISK ALL

CellCLI> DROP CELLDISK CD_02_cell09 ERASE=1pass NOWAIT
CellDisk CD_02_cell09 erase is in progress

Related Topics

Parent topic: DROP