Zeroing & naming partitions

[DaleMeyn]

Dave,
In your discussion wwith kswaty you said it is necessary to “zero”, rather than simply erasing when partitioning, which can be done by formatting the disk. There is no format option in OS 10.4.4. Instread, after selecting “Erase” in Disk Utility, one goes to “Security options” and clicks the button for “Zero out data”, then continues the erase. However, I’ve been running SD! successfully (post-disaster) with Sandbox, with all partitions merely erased. By the way, it took me a while to find out what “zeroing” a disk meant, somehow just didn’t make the connection. Your discussion with kswaty was extremely helpful for me. Two questions arise:

1. Why is it necessary to zero a disk or partition before putting SD! copies on them? Mine seems to work well without doing that. I could now go back and do it, starting over, now that I have learned to do it without vaporizing my user files, if it’s necessary.

2. I named my source partition “Mac HD”, Sandbox partition is named “Sandbox”, both on internal HD, and backup (on external disk) is simply “Backup”. That seems very satisfactory, nothing untoward is happening. Is there any problem with those names (vs “Macintosh HD” and “Macintosh HD Backup”? These make it easy to avoid confusion when setting up copy scripts and scheduled copying. One thing is certain: don’t ever change the name of the source partition after creating Sandbox, it doesn’t work.

Comment:
It took some time and experimentation to get it right, almost gave up on Sandbox. Strange things kept happening, as if a gremlin was loose. User files, user apps, even Mail Address book entries and Safari Bookmarks, disappeared, then sometimes reappeared after I rebooted from the source volume. When I erased Sandbox, all returned to normal. It seems to have been caused by leaving the names for the HD partitions as the partition utility assigned them, I.e., “Macintosh HD_1”, “Macintosh HD_2” (aka Sandbox), etc. When I re-partitioned Macintosh HD and renamed the partitions as above, all just came together and seems to work as advertised. I’m loath to repeat the experiment, so can’t be sure I all the scripts were assigned correctly, but I was really careful. It was as if Sandbox couldn’t keep the names straight because they were too similar.
Dale Meyn “the Eliminator”

[dnanian]

Hi, Dale.

Sorry for the imprecise language -- Formatting and Erasing are the same thing, as you discovered.

I suggest Zeroing when people are having trouble because it allows the OS to test the surface of the drive by writing to every part of it. That maps out any bad sectors, so you've got a clean surface. It's not necessary for all users.

There's no problem with the names you've selected. And -- you're right -- if you change the name of your drive, links won't work any more, so don't do that!

I've never seen anything like what you're talking about with a Sandbox, and we've had them for years. "Similar" names don't really matter... computers are pretty exact things, and we link to the name exactly as it was at the time of creation... I can't think of any reason things would vanish and reappear: you're literally using the same home folder...

[DaleMeyn]

It really seems that there is no need to update Sandbox from Mac HD, unless I for some reason decide to operate for a while from Mac HD as startup, in which case I just copy all files from Mac HD to Sandbox using Smart Update. Looking the other way, the only reason to copy back from Sandbox to Mac HD is if for some reason I didn't save an application (drag & drop type) or installer in the Desktop folder for later installation on Mac HD. Have I got this right? I'd be very reluctant to copy back except in an emergency, and then only with at least one up-to-date backup on the external HD. I actually did that once after everything was working well for a few days, with 2 backups ready just in case. It worked perfectly, no funny stuff ensued. But it was just an experiment with lots of backup available. Thanks again for your response. Dale Meyn

[dnanian]

Well, I always update the Sandbox whenever I update Macintosh HD. It ensures I'm working from the same base, and converts any "new" applications to shared ones.

"Cloning back" is certainly safe if you have a backup, and I do use this fairly often to apply an "approved" set of changes to the base. It's easier than reinstalling everything, but they are -- in the end -- basically equivalent.