07-18-2002 04:02 AM
Old box will be returned to HP.
If I only use rm or lvremove/vgremove commmands, how I can be sure that my company data will not be returned from disks?
What would be the most secure way to destroy old data?
07-18-2002 04:07 AM
Stopping short of an acid bath, this recent, lively discussion offers some other choices:
07-18-2002 04:08 AM
pvremove will remove the LVM information on the disk ... but if you want to be completely sure, you can use "dd" ...
07-18-2002 04:10 AM
If you have a device that is really empty, you could use this trick. Or maybe one of the forum members know how to implememnt /dev/zero?
07-18-2002 05:14 AM
To remove all the data from the disk, first remove the lv and then delete the VG's info from the disk and then do a dd to delete all possible data from the disk, say cxtydz
dd if=/dev/null of=/dev/rdsk/cxtydz bs=1024k
Hope this helps.
07-18-2002 05:21 AM
The thread I cited above...
...contains more information about '/dev/zero'. However, ff you are running 11.11 you should already have /dev/zero. If not, do this to create it:
# mknod /dev/zero c 3 0x000003 #...on 10.20
# mknod /dev/zero c 3 0x000004 #...on 11.x
# chown bin:bin /dev/zero
# chmod 666 /dev/zero
07-18-2002 05:44 AM
The *only* SURE way to completely remove data would be to crush & burn 'em.
Seriously, data has been retrieved from disks after up to 17 passes of random overwrites.
IF the pursuer is determined enough, it's only a matter of time & $ - they'll get it.
But normally 3-6 passes of random ones & zeros should be sufficient for most cases. IF you only overwrite w/zeros you may want to up that count some.
07-18-2002 06:11 AM
Do *not* use mediainit! mediainit *may* make the disk *less reliable*, but you won't *know* one way or the other.
The "Why?" is rather long. If you really want to know, search on "mediainit" and my name and you should find some pointers. If not, do the same search on Google Groups.
07-19-2002 08:15 AM
You might consider checking the link:
They have a program called unishread that might meet your requirements. I have not used this product, but based upon the write up on the site, it should serve your purposes.
We purchased a system with an external SCSI Hard Drive for classified information, then never used it!
07-19-2002 08:28 AM
Apparently they were so interested in just one disk, which was badly fire damaged (warped + melted) that they paid a small fortune to have the data restored... I guess they must have moved the heads manually.. in any case, moral is: be a real man, use a needle an magnet!
07-19-2002 09:04 AM
It may be funny, but it is also scary. We have had operators bring down the wrong systems, use the wrong tapes for backups and type in the wrong year for a time changes. Scary stuff!
07-19-2002 09:30 AM
07-22-2002 04:18 AM
As everybody said, data can still be retrieve, you need to repeat this operation a few times. Depending on the size of the drives, this procedure takes a lot of time.
07-22-2002 05:31 AM