Data Ontap Sanitization Operation - IBM N series Hardware Manual

By using Data ONTAP, IBM System Storage N series offers an effective sanitization method
that reduces costs and risks. The disk sanitization algorithms are built into Data ONTAP and
require only licensing. No other software installation is required.

13.3 Data ONTAP sanitization operation

With the disk sanitize start command, Data ONTAP begins the sanitization process on
each of the specified disks. The process consists of a disk format operation, followed by the
specified overwrite patterns that are repeated for the specified number of cycles. Formatting
is not performed on ATA drives.
The time to complete the sanitization process for each disk depends on the size of the disk,
the number of patterns that are specified, and the number of cycles that are specified.
Requirement: You must enable the licensed_feature.disk_sanitization.enable option
before you can perform disk sanitization. The default is off. However, after it is enabled, this
option cannot be disabled, and some other features cannot be used. This option cannot be
accessed remotely and must be configured by using the console.
The following command starts the sanitization process on the disks that are listed:
disk sanitize start
[-p <pattern>|-r [-p <pattern>|-r [-p <pat_tern>|-r]]] [-c <cycles>] <disk_list>
where:
The -p option defines the byte patterns and the number of write passes in each cycle.
The -r option can be used to generate a write of random data, instead of a defined byte
pattern.
If no patterns are specified, the default is three, which uses pattern 0x55 on the first pass,
0xaa on the second pass, and 0x3c on the third pass.
The -c option specifies the number of cycles of pattern writes. The default is one cycle.
All sanitization process information is written to the log file at /etc/sanitization.log. The
serial numbers of all sanitized disks are written to /etc/sanitized_disks.
Disk sanitization is not supported on solid-state drives (SSDs). It does not work on disks that
belong to SnapLock compliance Aggregates until all of the files reach their retention dates.
Sanitization also does not work with Array LUNs (N series Gateway). The disk sanitization
command cannot be run against broken or failed disks.
The command that is shown in Example 13-1 starts one format overwrite pass and 18 pattern
overwrite passes of disk 7.3.
Example 13-1 The disk sanitize start command
disk sanitize start -p 0x55 -p 0xAA -p 0x37 -c 6 7.3
Attention: Do not turn off the storage system, disrupt the storage connectivity, or remove
target disks while sanitizing is performed. If sanitizing is interrupted while target disks are
formatted, the disks must be reformatted before sanitizing can finish.
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IBM System Storage N series Hardware Guide