• Drives, partitions, formatting w/Mac's + PC's

by: ds store

Last modified: May 17, 2012 5:53 PM

1 17882 Last modified May 17, 2012 5:53 PM

Hello and welcome to my User Tip.

I will explain to you just the basics how storage drives operate in regards to different operating systems, formatting and partitions, especially sharing data with Windows PC's which is the most common asked about issue.

For simplicity sake, I have stuck to the most current used formats and steps on Mac's and PC's that your likely to encounter and encouraged to use now.

Quick methods

Whenever you changing the drive, there is the potential for the lost of data.

So make sure you have a copy of the data off the drive your attempting to change and physically disconnect all other non-essential drives so no mistakes occur.

#1 If you want to format a drive, USB Thumb drive etc., to only work with a recent Mac and to boot OS X with

Open Disk Utility and select the drive makers name and size on the far left, then Partition: Options: GUID partition table and Format: OS X Extended (Journaled) name it and click Apply.

#2 Format a drive, USB thumb drive etc., to work with Mac or a PC, on a PC. (most compatibility)

Take it to the oldest Windows PC your going to share data with, usually XP, right click on it's icon and select format:

exFAT - for large video/movie files use +4GB (pre-10.6.5 Mac's can't read this format, use FAT32)

FAT(32) - for most anything, small use (under 4GB sized files), thumb drives, most compatibility with connecting to TV's consoles and other devices

If your Windows XP machine doesn't have exFAT, there is a free download from Microsoft.

#3 Format a drive or USB thumb drive etc., to work with Mac or PC, on a Mac (most compatibility)

Take the drive to the oldest OS X version on the Mac(s), Open Disk Utility and select the drive makers name and size on the far left, then

Partition: Options: MBR partition table

Format: MSDOS (FAT32) - for under 4GB files and to work work with consoles, devices that need firmware etc., or

Format: exFAT - for over 4GB sized files (Mac's pre OS X 10.6.5 won't have exFAT)

#4 Format a drive or USB thumb drive etc., to work with only between recent Mac 10.6.5+ & Vista-Win 7, on a Mac

Open Disk Utility and select the drive makers name and size on the far left, then

Partition: Options: GUID partition table

Format: MSDOS (FAT32) for under 4GB sized files, or

Format: exFAT - for +4GB sized files (exFAT is proprietary, patent pending, may have to pay later)

https://en.wikipedia.org/wiki/ExFAT

Trouble with transfering data or formatting?

Reducing bad sectors effect on hard drives

Partition Map or Table - is instructions written on the drive that tell the hardware it's running from: what, how many, and where the partitions are on the drive. There is only one partition map on the drive. It can be MBR or GUID.

Partition - is a space on the drive that appears as another drive, but still resides on the same piece of physical hardware.

Formatting - is how a entire drive or partition is structured to hold data, one drive can be partitioned into many separate partitions each with their own formatting. The Partition Map holds all the information of what is what.

Changing the partition map/table scheme will erase all data on the entire drive, it's like burning a treasure map, no directions anymore.

Changing the format of a single partition on a multi-partitioned drive only erases the data on the partition being formatted.

Questions

How do I format a entire external drive on a Windows PC?

Open the file manager and locate the drive (empty of data, or data you wish to delete) and right click on it and "format" and choose a format, Windows will create the MBR or GUID automatically if there is none depending upon what version of Windows your using.

It's best to format on the oldest PC being used as the future versions of Windows (and Mac's) can read the older format.

I have a drive from a Windows PC, the Mac can/not read or not write to it. What do I do?

It's likely formatted NTFS by Windows, it's best to take it back to the Windows machine, remove the data and reformat it FAT32 or exFAT, then place the data back on.

Recent Mac's can read NTFS, but not write to it, so this might be enough to transfer data off, then reformat the drive. Check the data was transfered and is accurate before changing the drive format and thus erasing it.

There is third party software than can be installed enable read/write of the NTFS format on Mac's, you'll need to search online for it. It's hassle, you'll have to pay and have it updated like any other software. A neutral exFAT or FAT32 (MSDOS) format is better as either platform can read it without more software installed.

How do I format a entire external drive on a Mac?

Unmount and disconnect all other drives to prevent a mistake. Open Disk Utility in the Applications/Utilities folder and select the drive on the far left with a makers name and size, then click Partition tab: Options: (for a establishing a specific partition map scheme), partitions, and Format (for selecting a specific format for the drive/partitions)

How do I format a drive for booting with a Mac?

Same steps as above, choose GUID as the Partition map under Options, and OS X Extended journaled (HFS+) as the format for the partition your going to be installing OS X into.

There is no choice for MSDOS format on the PC, or FAT32 on the Mac, what do I choose?

FAT32, if it just says FAT, it usually means FAT32 (as FAT16 is on the way out.). MSDOS is what Apple calls FAT32.

I formatted the external drive exFAT or FAT32 (MSDOS) on my Mac and took it to a PC and it asks me to format!

Don't format it (unless your willing to erase all the data on it)

Take the drive back to the Mac and copy off the data (if you don't have a copy on the Mac already) and try formatting it again, this time making sure to select the Option: MBR then chose the format.(exFAT or MSDOS) and click apply. If it still doesn't work, format the drive on the PC.

I went to format a Bootcamp / second partition on my boot drive and it's restricting my size, I know I have more free space available

Your partitions are stacked like so before creating the second partition.

EFI (hidden)

OS X - say 100GB

10.7+ Recovery HD (if on 10.7+, hidden)

Your partitions are stacked like so after creating the second partition.

EFI (hidden)

OS X - 50GB

Bootcamp / Second Partition - 50GB

10.7+ Recovery HD (if on 10.7+, hidden)

When you try to create a Bootcamp / Second partition it's started from the bottom free space remaining on the OS X Partition and works it's way up until it hits data written on the drive from OS X. If that partition size is too small to install Windows, then Bootcamp will say it can't continue.

Hard drives write data on a drive from the top down where it can find space. When files are deleted it leaves holes and thus the data on the drive isn't all nice and compact all the time to provide all the free space at the bottom of the drive to create the second partition.

To fix this requires cloning one's OS X partition to a external drive, hold option boot from it to check it out, erase the OS X partition in Disk Utility (booted on the clone) onto the internal drive OS X partition, then reverse clone the external OS X partition back onto the internal OS X partition.

This will effectively write all the data of the OS X partition starting from the top of the partition and working downward, so when you boot off the internal OS X partition you will be able to format your second partition with more of your remaining free space available.