well, you could always use dd. The command I would use is: dd if=/dev/zero of=/dev/<specific device here> and then let it run. it might take a while to erase, but there will not even be partition information on there afterward. after that, you can use disk utility to repartition and format that usb device.
-eric On Dec 9, 2016, at 3:41 AM, Paul Hopewell wrote: > Hello, > Further to my earlier post about erasing a folder without going via trash….. > > I I am running the latest El Capitan on my late 2008 iMac. > I have a 256 GB memory stick with I have used as a time machine backup disk > with encryption. I have also used it as the target disk for a SuperDuper! > backup of my iMac. > The experience was not entirely satisfactory as 256 GB is not enough for more > than a couple of time machine backups and a SuperDuper! backup. Also both > time machine and SuperDuper! backups were very slow, much slower than a USB > attached external hard disk drive. > > So I now want to empty the 256 GB memory stick and reuse it for other > purposes. I first tried using disk utility to erase the disk but that did not > work as it said I did not have the authority to do the erase. > I then tried erasing each folder with Command+Ottion+Delete. That took a long > time and also did not work. > > I note the posts about using terminal commands. I am not familiar with that > so am rather nervous about using it. I am also wondering about the effect of > my having originally used the memory stick for an encrypted time machine > backup with the password saved in the keychain. How do I mark the memory > stick as not encrypted? > > In summary I want to restore the memory stick to its original empty > unencrypted state. What do you recommend? > > Many thanks. > > Paul Hopewell > > -- > The following information is important for all members of the Mac Visionaries > list. > > If you have any questions or concerns about the running of this list, or if > you feel that a member's post is inappropriate, please contact the owners or > moderators directly rather than posting on the list itself. > > Your Mac Visionaries list moderator is Mark Taylor. You can reach mark at: > [email protected] and your owner is Cara Quinn - you > can reach Cara at [email protected] > > The archives for this list can be searched at: > http://www.mail-archive.com/[email protected]/ > --- > You received this message because you are subscribed to the Google Groups > "MacVisionaries" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/macvisionaries. > For more options, visit https://groups.google.com/d/optout. -- The following information is important for all members of the Mac Visionaries list. If you have any questions or concerns about the running of this list, or if you feel that a member's post is inappropriate, please contact the owners or moderators directly rather than posting on the list itself. Your Mac Visionaries list moderator is Mark Taylor. You can reach mark at: [email protected] and your owner is Cara Quinn - you can reach Cara at [email protected] The archives for this list can be searched at: http://www.mail-archive.com/[email protected]/ --- You received this message because you are subscribed to the Google Groups "MacVisionaries" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/macvisionaries. For more options, visit https://groups.google.com/d/optout.
