On Nov 10, 2009, at 20:55, Mark A. Carlson wrote:

Typically this is called "Sanitization" and could be done as part of an evacuation of data from the disk in preparation for removal.

You would want to specify the patterns to write and the number of passes.

See also "remanence": http://en.wikipedia.org/wiki/Data_remanence (S)ATA actually has a protocol command ("secure erase") that will cause the disk to over write all of its sectors, and not be usable until its done. This doesn't exist in SCSI / SAS / FC as far as I know. Generally speaking one over write is sufficient to prevent data from being accessible, but various government standards specify anywhere between one and four passes: http://en.wikipedia.org/wiki/Data_erasure Degaussing or complete destruction is usually necessary for the "top secret" stuff. DBAN is a useful (open-source) utility that I tend to recommend for regular folk: http://www.dban.org/ While it could be useful, there are penalties in various jurisdictions for leaking data (especially with government-related stuff), so I'm not sure if Sun would want to potentially expose itself to inappropriate use that doesn't clean everything properly. With ZFS encryption coming up, it could be sufficient to have your data sets encrypted and then simply "forget" the key. The data is still technically there, but (theoretically) completely inaccessible. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ----- End forwarded message ----- -- Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE