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Formatting an External Hard Drive

Avatar Jeanette Jones
I've just bought a WD Elements 2TB External Hard Drive and need some help in formatting it and using it for Time Machine backups for my MacBook Pro bought July 2012, running Mountain Lion and also my iPad 2 and iPhone 6, (that should be iPhone 5), both updated to iOS7. Just to say that I understand some Computer terminology but haven't got a clue about how to set up computers, (that's why I've joined WAMUG, to get some knowledge).

I'm not sure if I should have more than 1 partition, one being a boot disk and another for the Time Machine files, and should I make more than 2 partitions given the size of it and what size should I make the partitions? Also should I set the first partition scheme to GUID to be able to boot from it?

I've had a look through previous discussions and come across Lionel's 'A Simple Guide to creating a Backup Drive' in 'Re: Useful tips to maximise system reliability.' and wonder if it is still valid given this was written in September 2012 and technology is changing so quickly? I assume that where Lionel says to connect to the Firewire port, I would use the USB port instead, (the drive is USB3).
When I want to make a backup of the Macintosh HD, would I still use 'Carbon Copy Cloner' or is there anything loaded in Mountain Lion that I could use?
Thanks in advance.

Re: Formatting an External Hard Drive

Avatar Euan Williams
Hi Jeanette, welcome to WaMug.

Lionel wrote a clear concise set of instructions, and this is to build on, and to an extent update them. These days drives are just huge. You are right to be concerned that a single 2Tb (or two 1Tb partitions — one for a boot disk and a second for Time Machine backups) would be unwieldy. More, smaller, partitions would be sensible.

Here are a few things to consider, and opinions do (and should) differ about them. You will hear all sorts of views, and you will make your own choices. It covers suggestions both for external drives and internal ones.

Time Machine:
You should be cautious about using the default Time M/c settings. Much the best thing to do is to make an initial TM/c backup and then switch it “off” most of the time, perhaps letting it do its thing at the end of a days’s work or while you are in the middle of a complex job. Comparing huge data sets on two drives to back up just a few minor alterations is a great way to wear down even the best made drive (or SSD). TM/c has a small icon in the top menu bar which allows you to switch it on for a single backup without switching on the “once an hour” option.

To contemplate a huge TM/c partition is foolish; they can, and sometimes do, get corrupted just like anything else in computer data. (Personally I prefer to just copy my new files with a different version number onto another drive or memory stick. It’s simple and very reliable.)

Spread the risk:
Don’t put all your eggs in one basket. Suppose you are “safely backed up” to your 2Tb drive, and the family dog knocks it over… Bang: all your backups lost in one go, no matter how many partitions.

It’s safer to keep your backups duplicated on a number of smaller drives (1Tb is a useful economical size) distributed in various different cupboards, houses and offices with DVDs in airtight ammmunition boxes (yes) as a backstop. Hard drives and SSDs do fail sooner or later, and working them hard with huge data transfers may hasten that evil moment.

If one moderately sized partition is corrupted on a particular drive, data on other partitions on the same drive may well be healthy. You could be glad, very glad… (it’s Halloween).

Keeping up with OS development:
As OS X develops some apps no longer work with newer versions, and some very useful ones don’t work with older OS versions, with three partitions you can have two versions concurrently and the possibility of the third newest “to see how it goes”. This strategy works extremely well. Cloning is very useful before System updates because a clone, unlike TM/c, can start up your Mac.

Partition size:
huge partitions are normally a nuisance because copying or cloning them takes such a vast amount of time. If you gradually build a 70 Gb iPhoto library and want to back it up you will be copying for a serious length of time with a USB2 drive, faster with USB3, or you are using Thunderbolt drives. Imagine that you have a 500Gb iPhoto library… Make separate iPhoto libraries for different groups of events and keep the size reasonable - 15Gb max perhaps?

So what is a useful partition size? For your internal MacBook Pro, perhaps with a 500Gb hard drive if not an SSD, consider partitioning it into three, each partition being about 166Gb. With an SSD of moderate size, perhaps just two or one. For your external drives you might divide them into 250Gb partitions unless you have a special need for a huge partition (so your partitions might be, say 6 x 250Gb with one more at 500GB making 2Tb although for most purposes 500Gb is vast.)

This allows you
a. to keep the day to day files in trim as they can’t grow to a ridiculous size.
b. to make backing up and cloning a reasonably fast operation by keeping the totality of files to a modest size.
If you decide to clone one of these 165Gb partitions (as you will) it may involve cloning perhaps 125Gb of actual data, and if your backup external drive has, say, 250Gb partitions there is plenty of room to keep backing up bit by bit from that 125Gb initial transfer. By doing subsidiary backups to DVD, or other drives, that working partition won’t be a ridiculous burden.

Cloning:
Carbon Copy Cloner makes (optional) clones of your emergency startup partition easy. This is a subject all on its own. I use CCC all the time and it has never, ever, let me down. Worth every penny, and no, not even my blissed-out Mavericks has cloning software included. Make sure that whatever you use is certified for your version of OS X.

Cloning is an essential backup and enables the external drive (or other internal partition) to start up your Mac so you can blithely carry on with your work if some digital disaster should befall you. CCC costs after the first thirty days, but is worth every penny. It can clone your (invisible) emergency start-up partition (do this just once on any clone partition for a given major (e.g. Lion > Mountain Lion) version upgrade of OS X).

Drive formats:
always make your drives “Apple Extended (journaled)” and, these days, GUID, as you are right to suggest. You can use a PC format file to store data files — as you might normally do on memory sticks, but NOT to store apps nor system files (PCs don’t understand UNIX). If the first partition is GUID, then all subdividing partitions will be as well. See the Options sub-menu in Disk Utility.

Method and Tool:
Disk Utility (Applications > Utilities) is the app that does the bizz. Note the distinction Lionel makes between the drive mechanism in the left column (e.g.: toshiba type sabc123987), and the initial and subsequent partitions (e.g. Macintosh HD). To convert your new drive from Windows to Apple Extended (journaled) you need to select the mechanism, not the partition. Erase and format the “mechanism”, then erase the new “untitled” partition in favour of whatever partition scheme you have decided on. Lionel explains this clearly.

Important and special consideration:
The proprietary backup software sometimes supplied by drive manufacturers does not generally play well with MacOS X and the current WD offering with Mavericks is known to be able to ruin your day. The advice is to erase all those offerings no matter what drive they come with. Apple stuff works, is comprehensive, and efficient.

Drive formatting seems a weird thing to do — first time. Take your time and be cautious, you can change the partition sizes until you’re happy. Only then put your data on the drive.

Re: Formatting an External Hard Drive

Avatar Jeanette Jones
Euan, thank you so much for your comprehensive reply, it has given me a lot to think about. I don't use the MacBook Pro very often and had planned to use Time Machine about once a week, rather than keep it connected, so that tallies with your advice.

I use the iPad and iPhone daily, so this is mainly what I'll be backing up and I was surprised to discover that backing up through iTunes to the computer writes over the previous saved backup, rather than make a new copy. This is one reason for getting the external drive as well as realising that it's an essential thing to back everything up frequently because 'as sure as eggs is eggs', there will be a point when something will happen and I'll wish I had backed up. Case in point, I may have been able to go back to iOS 6 if I had Time Machine backups! I am holding back on Mavericks for the moment and hopefully with the new drive I can try it out on it's own partition when any hiccups have been sorted out.

Thank you.

Re: Formatting an External Hard Drive

Avatar Mick Burrell
To add to Euan's comprehensive reply and risk muddying the waters:

I use SuperDuper! from shirt pocket.com as I feel the user interface is (was) easier to understand and use than CCC when I was looking. But they both do the same job.

I don't think you would have been able to go back to iOS 6 from a backup of your mobile devices whether you had them backed up to iTunes or iCloud. I'm pretty sure that the backup only backs up your data as the OS and any app or music purchases can be downloaded again FOC. Perhaps someone who has restored a mobile device from a backup can confirm or correct this.

Re: Formatting an External Hard Drive

Avatar Euan Williams
More about the Western Digital's drive backup software SNAFU with Mavericks is here.

If you are using Mavericks and WD drives ensure that the WD-supplied "backup" software has been deleted.

Other drive manufacturers sometimes supply similar software as a selling point, but it's probably more sensible and efficient to stick to Apple's solutions.
 
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