How to Erase Bulk Storage Devices

NDW is capable of wiping thousands of storage devices simultaneously. But before we explore this area, lets discuss the challenges that different storage devices pose.

Normally, Windows, Unix, Linux or Mac OSX support only 512 byte sector size. If you present 512 byte sector HDD to any of the operating system the hard disk drive is instantly available for use. But if the HDDs sector size is 520, 524, 528 or 1024 or 2048, 4096 and 8192 bytes sector size, in this case your operating system may detect the HDD but would refuse to read/write data to such storage devices. Unless it is converted to 512 bytes sector size.

Not all and some enterprise storage devices, such as SAN, Disk Arrays, 15K, 10K, 7.2K SAS, SCSI , Fiber channel drives are non-standard sector size, for example. Most NetApp storage devices are either 520, 524 or 528 bytes sector size. The reason some storage devices use sector size great than 512 to improve performance, throughput and IO. For example: a storage device that is 4096 physical physical sector, this means device can store large chunk of data per sector and there will be lower overheads for IO, even if the storage devices physical sector size is greater than 512 bytes but the data plane of such storage devices will present logical sector size 512 bytes to the operating system.

NDW can automatically detect the physical sector size for each storage device and convert sector size to 512 bytes, so the hard disk drives can be data wiped normally and instantly available for use with any operating system.

Now let's discuss how different storage devices can be wiped in bulk with NDW.

SAS, SCSI, SATA 10K 15K Hard Drives Bulk Erase with NDW

NDW can erase data from all sort of large quantity storage devices simultaneously. Let's discuss how the storage devices should be presented to NDW in order to erase data effectively.

Each hard disk drive should be presented directly to the OS without any raid configuration or raid controllers. This means NDW OS should have direct access to each storage device without any intermediate hardware or software raid configuration.

NDW non-supported configuration for Bulk Erase

Each disk array or storage array is connected to computer machine via HBA (Host Bus Adapter) also called (Raid Controller). These HBAs then provides ability to configure RAID for redundancy. But RAID configuration is not supported by NDW because it needs direct access to each drive so it can effectively erase data bit by bit, sector by sector and block by block from each storage device.

NDW Supported Configuration for Bulk Erase

Most HBAs firmware can be flashed to provide JBOD (Just bunch of drives) capability. This is also known as IT mode or JBOD mode. When HBA in JBOD is used, it presents each drive directly to the OS without any intermediate bottleneck and without RAID configuration. This way OS can directly access each hard disk drive. For example, following HBA can be flashed to JBOD and IT mode.

LSI Logic / Symbios Logic SAS2116 PCI-Express Fusion-MPT SAS-2
LSI SAS 9300-8I 12Gbps SAS SFF-8643 JBOD HBA P16 IT Mode
Adaptec RAID ASR-6405E 128MB - FH PCIe-x1 0,10, 1E JBOD SAS RAID Controller
Cisco UCSC-SAS12GHBA 12Gb/s SAS 24-Channel Storage HBA Controller 2x SFF-8643

Above is just an example of HBA JBOD IT mode cards, kindly refer to stoarge array manufacturer's specifications for choosing JBOD HBA adapters.

For example, if you want to erase 24 x 2.5 inch SAS 15K hard disk drives. Your configuration would look like this.

A host machine with LSI Logic / Symbios Logic SAS2116 PCI-Express Fusion-MPT SAS-2

A NetApp DS2246 disk array with 24x 2.5 inch SAS drives populated.

Connect your host machine to NDW network and boot in Network PXE. As explained above, most enterprise storage devices are non-standard byte sector. NDW will boot your host machine from network and inspect the hardware and if non-standard sector size is detected for any storage device it will automatically be converted to sector size 512 bytes. Sector size conversion is time consuming process because the entire geometry of hard disk drive is changed, all bits across entire hdd are rewritten to sector size 512 bytes. Therefore sector size conversion may take long time to process. This process runs in parallel for all hard disk drives in array. If different speed and capacity size hdd are used in the same array, Some drives conversion may complete early than others due to data throughput and size capacity. You may see following on host machine's screen while converting to 512 bytes sector.

Important Note: This is just a single host machine connected with disk array 24 x sas drives populated. You can use multiple machines with multiple arrays. For example 10 host machines each with HBA JBOD card installed and each host with 4 x disk arrays connected in daisy chain, 24x4 drives. So each host would give you 96 disks, so in total 10 hosts with 96 drives each, that would be 960 hdds wiping data in parallel. You can increase the hosts and arrays as desired.

HDD1 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 74.99% done
HDD2 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 75.99% done
HDD3 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 76.99% done
HDD4 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 76.99% done
HDD5 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 77.99% done
HDD6 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 78.99% done
HDD7 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 79.99% done
HDD8 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 80.99% done
HDD9 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 81.99% done
HDD10 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 82.99% done
HDD11 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 83.99% done
HDD12 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 83.99% done
HDD13 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 84.99% done
HDD14 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 85.99% done
HDD15 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 86.99% done
HDD16 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 87.99% done
HDD17 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 88.99% done
HDD18 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 88.99% done
HDD19 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 89.99% done
HDD20 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 90.99% done
HDD21 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 91.99% done
HDD22 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 92.99% done
HDD23 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 92.99% done
HDD24 - NetApp  - HDD_model - HDD_Serial_Number - Converting to 512 Bytes Sector Size: 93.99% done

Important note: If you are connecting disk arrays in daisy chain, the data wiping throughput may become slower because the bus speed / bandwidth between host machine HBA and disk arrays is limited. Also the CPU usage on host machine may increase. We recommend you try different configuration and settle for one that best suites your needs.

The sector conversion progress displayed above is just an example, this progress on your host machine will display actual HDD Vendor name, HDD Model Number and HDD serial number.

Once this conversion process is completed data has already been erased because of the conversion process, But NDW will continue to wipe data using usual methods. You may see following on your screen.

Above displayed image is used for illustration purposes, display on your host machine may differ. But it would look like more or less the same.

While NDW data erasure is continuing to run, you can view this progress from management console machine by browsing to http://192.168.1.253

You may click widgets above to drill down to each machine and view progress for each machine from central management console.

You may click widgets above to drill down to each Hard Disk Drive to view progress for each machine, and on the next page can drill down further into each hard disk drive to view progress as well as performance data related to each hard disk drive.

Important Note If you wish to drill down further into each Hard Disk Drive, you can do so by clicking the HDD widget, this will open up another page which will show detailed information related to that specific Hard Disk Drive. See below an example.

When data wiping has completed its run, labels for each hard disk drive will automatically be printed. See below.

While data wiping is continuing to run or when the data wiping has finished, you can view the reports and access the data erasure certificate from the web management portal. See below example.

To learn how to access reports, graphs, certificates and other management related tasks kindly refer to the user guide.

Should you have questions and need support kindly contact email: support (@) greatengland.co.uk