FAT32 partitions

[jonathaw]

Hey all, I thought that FAT32 was called such because it's limited to 32 GB partitions, but Mark informed me that it's actually because it uses 32 bits for the cluster entries in the table (as in the File Allocation Table). Duh!
However, I was still curious as to why I (and many others) thought it was the partition size. Well, this is taken from Microsoft's website:

In theory, FAT32 volumes can be about 8 terabytes; however, the maximum FAT32 volume size that Windows XP Professional can format is 32 GB. Therefore, you must use NTFS to format volumes larger than 32 GB. However, Windows XP Professional can read and write to larger FAT32 volumes formatted by other operating systems.

So it's because Windows sucks at formatting, I guess.

[fischerm]

After googling this for a while, it seems that the 32GB limit is simply an arbitrary limit Microsoft has imposed on its own formatting tools when partitioning a Fat32 volume. Microsoft clearly wants you to be using NTFS. This isn't a problem with the fat32 specification, other programs (partition magic, a mac, etc) can create larger partitions just fine. There are likely 3rd party free-ware apps that will create the correct partitions for you on Windows.

[jonathaw]

Just wanted to add a few more things:
1) In DiskUtility, choose MS-DOS to format as FAT-32.
2) OS 10.3 can read NTFS disks, but not write to them.
3) If you try to write to an NTFS formatted disk on a Mac, Bill Gates will come to your house and kill your pets.

[abudhu]

NTFS allocation table/security is far better than FAT 32. Main use Windows whats you formatting in it.

In anycase, I believe that Linux's JPS system is far better.

[kaufmann]

FAT32 has its limitations, but it's currently the most-useful filesystem for disks that have to be shared among multiple OS's when those OS's include Windows. HFS and HFS+ and EXT2 and EXT3 (much less JPS or XFS) don't work well on Win systems (although if you spend $$ you can get HFS+ for windows), and NTFS doesn't work will on non-Win systems. FAT32 is the common denominator.

Win refuses to format FAT32 bigger than 32GB because the scandisk utility provided with Win will corrupt and completely fubar any parition larger than that size. Rather than fix scandisk, M$ decided to just make sure than no larger partition could be formatted. (Actually, it doesn't refuse to format - it goes through the motions for perhaps hours, then when almost done quits and reports "partition too large" or some such unhelpful message, thus wasting a bunch of your time.)

Happily, other OS's are capable of making and formatting FAT32 paritions which can then be mounted on Win. (Just don't run scandisk on them ;-).

You could use BeOS. You could use Linux. Let's go with OS-X for today:

To deal with partitioning and formatting you need to know about three programs: diskutil, fdisk, and newfs_msdos. Oh, df is good to know too. To make best use of this posting, copy it into a text editor, change the font to something fixed-width like courier, and print it out.

First, plug in the relevant drive. My example is a firewire drive. Then run "diskutil list." See below:

Hostname:~ user-person$ diskutil list
/dev/disk0
#: type name size identifier
0: Apple_partition_scheme *152.7 GB disk0
1: Apple_partition_map 31.5 KB disk0s1
2: Apple_HFS Maxtor 152.5 GB disk0s3
/dev/disk1
#: type name size identifier
0: Apple_partition_scheme *152.7 GB disk1
1: Apple_partition_map 31.5 KB disk1s1
2: Apple_HFS Macintosh HD 152.5 GB disk1s3
/dev/disk2
#: type name size identifier
0: Apple_partition_scheme *189.9 GB disk2
1: Apple_partition_map 31.5 KB disk2s1
2: Apple_HFS FW190 189.8 GB disk2s3

_________________________

Note that I have two internal hard drives. They are /dev/disk0 and /dev/disk1. The firewire drive is /dev/disk2 and currently has an Apple HFS partition called "FW190."

First, unmount the current partition. You could drag-to-trash, or you can use the command line. In my example, the commands are the stuff after the $. Your prompts will of course not be "Hostname" and "user-person."

Hostname:~ user-person$ diskutil unmount /Volumes/FW190
Volume /Volumes/FW190 unmounted

____________________________

If there was a mounted partition on the desktop, it will disappear. Next, we make the new partition. This will *destroy* the existing partition and all the data on it, so go back now and copy it over somewhere if you care about that.

We'll use fdisk. Note that the device name has an "r" in front of it for this. I don't know why, so don't ask. Be *very* careful you're specifying the right disk, or you could blow up the whole current host filesystem.

Hostname:~ user-person$ fdisk -ia dos /dev/rdisk2
fdisk: could not open MBR file /usr/standalone/i386/boot0: No such file or directory

-----------------------------------------------------
------ ATTENTION - UPDATING MASTER BOOT RECORD ------
-----------------------------------------------------

Do you wish to write new MBR and partition table? [n] y
_______________

The GUI might notice that you've "inserted" a new disk just now and ask what to do. Choose "ignore." Now let's go back and look at the diskutil list:

Hostname:~ user-person$ diskutil list
/dev/disk0
#: type name size identifier
0: Apple_partition_scheme *152.7 GB disk0
1: Apple_partition_map 31.5 KB disk0s1
2: Apple_HFS Maxtor 152.5 GB disk0s3
/dev/disk1
#: type name size identifier
0: Apple_partition_scheme *152.7 GB disk1
1: Apple_partition_map 31.5 KB disk1s1
2: Apple_HFS Macintosh HD 152.5 GB disk1s3
/dev/disk2
#: type name size identifier
0: FDisk_partition_scheme *189.9 GB disk2
1: Windows_FAT_32 189.9 GB disk2s1

____________________

Note that /dev/disk2 now has a "Windows_FAT_32" partition, but currently no volume on said partition. We can also inspect the partition table on /dev/disk2 with the fdisk command. Note that again we call it /dev/rdisk2 rather than /dev/disk2:

Hostname:~ user-person$ fdisk /dev/rdisk2
Disk: /dev/rdisk2 geometry: 24792/255/63 [398297088 sectors]
Signature: 0xAA55
Starting Ending
#: id cyl hd sec - cyl hd sec [ start - size]
------------------------------------------------------------------------
*1: 0C 0 1 1 - 1023 215 63 [ 63 - 398297025] Win95 FAT32L
2: 00 0 0 0 - 0 0 0 [ 0 - 0] unused
3: 00 0 0 0 - 0 0 0 [ 0 - 0] unused
4: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

_____________________________

Time to format that partition! In this example, the new volume name is "BigFAT", and the partition is /dev/disk2s1 (that means disk 2, slice 1):

Hostname:~ user-person$ newfs_msdos -F32 -v BigFAT /dev/disk2s1
newfs_msdos: warning: /dev/disk2s1 is not a character device
/dev/disk2s1: 398199744 sectors in 6221871 FAT32 clusters (32768 bytes/cluster)
bps=512 spc=64 res=32 nft=2 mid=0xf0 spt=32 hds=255 hid=0 bsec=398297025 bspf=48609 rdcl=2 infs=1 bkbs=6

_______________________________

Checking again with diskutil list, then mounting with diskutil mount, and showing mounted volumes with df:

Hostname:~ user-person$ diskutil list
/dev/disk0
#: type name size identifier
0: Apple_partition_scheme *152.7 GB disk0
1: Apple_partition_map 31.5 KB disk0s1
2: Apple_HFS Maxtor 152.5 GB disk0s3
/dev/disk1
#: type name size identifier
0: Apple_partition_scheme *152.7 GB disk1
1: Apple_partition_map 31.5 KB disk1s1
2: Apple_HFS Macintosh HD 152.5 GB disk1s3
/dev/disk2
#: type name size identifier
0: FDisk_partition_scheme *189.9 GB disk2
1: Windows_FAT_32 189.9 GB disk2s1
hostname:~ user-person$ diskutil mount /dev/disk2
Volume /dev/disk2 mounted
hostname:~ user-person$ df -h
Filesystem Size Used Avail Capacity Mounted on
/dev/disk1s3 153G 30G 123G 19% /
devfs 91K 91K 0B 100% /dev
fdesc 1.0K 1.0K 0B 100% /dev
<volfs> 512K 512K 0B 100% /.vol
/dev/disk0s3 153G 136G 16G 89% /Volumes/Maxtor
automount -nsl [234] 0B 0B 0B 100% /Network
automount -fstab [238] 0B 0B 0B 100% /automount/Servers
automount -static [238] 0B 0B 0B 100% /automount/static
/dev/disk2s1 190G 192K 190G 0% /Volumes/BIGFAT

_________________

That's it! We've created a 190GB FAT32 volume called BIGFAT. Try this at home (or school)!


-ck

[abudhu]

^^ Oh My..

Good to know...I suppose.

There are ways to get around Microsofts 32GB FAT32 limitation. Google around for it. People on other Computer Related forums have done it...

[amichel]

The main drawback I know of on FAT32 partitions is the 4gb file limit. You can't store files greater than 4gb in size on a FAT32 disc. This is a major problem if you're working with large video streams, or even with DVD images. In general, FAT32 is good for small utility disks, but bad for anything involving large files and large numbers of files.

JFS I don't know much about. ReiserFS is my linux FS of choice. Supposedly it really shines when you deal with multitudes of small files. It is not apparently significantly worse at handling large files, it is just paricularly good at handling serious numbers of small files. Honestly, I've never noticed any performance impact from my FS between EXT3 and Reiser, serving MySQL, web, e-mail, etc from my linux boxes. Even boxes that got a fair amount of traffic didn't seem to benefit a great deal from either.

I put FAT32 on my USB keychains, my iPod is FAT32, but if it's a real sizable hard disk that I intend to use regularly on a platform, I just choose to make it static and use whatever works best for that OS, NTFS for Win, HFS+ for Mac, Reiser on Linux. Networking speeds are at a point that I can transfer most files in a reasonable amount of time using Samba or NFS or something similar to do the work for me. With a gigabit ethernet network, sharing a portable disk between all my stations is in the range where the time lost in network transfering is made up in the simplicity of drag and drop.

[dparm]

I'm waiting for WinFS...reports say that Microsoft will be releasing it as part of a "service pack" after Longhorn ships to the public.

[abudhu]

I'm waiting for WinFS...reports say that Microsoft will be releasing it as part of a "service pack" after Longhorn ships to the public.

WinFS won't be shipped with the normal Loghorn. Its an add-on? How lame.

One bit of bad news is that the oft-touted WinFS storage engine will not be included in Longhorn. However, there's been a bit of misconception about WinFS and which features it enables, and Sullivan was quick to clarify that. "Longhorn will still feature a very rich search experience," Sullivan said. "It's kind of a mistake to equate local search with WinFS. They are different platform elements. So local search will still happen, and we will still deliver a very compelling full text search in Longhorn, alongside new shell capabilities. This will provide some semblance of the 'Find My Stuff' experience. But it won't be the full relational store with deep integration and platform exposure via APIs. For end users, however, it will be the same. We will offer a very compelling user experience for local search inside of Longhorn."

WinFS will ship in beta form when Longhorn is released and will now ship simultaneously on both Longhorn client and Longhorn Server, the latter of which is due in 2007. This year-long delay actually answers a key customer request, because there was some confusion previously about whether WinFS would ship with Longhorn Server. Now, Microsoft is clearly telling us that WinFS is a key feature of Longhorn Server. Incidentally, existing Longhorn users will be able to get WinFS for free when it ships, though the delivery vehicle for that product has yet to be announced.

[dparm]

Longhorn Milestone 9 (M9) and platform complete
March 2005

Longhorn Beta 1
Late May 2005

Longhorn Beta 2
October 2005

Longhorn Release Candidate 0 (RC0)
Late February 2006

Longhorn Release Candidate 1 (RC1)
April 2006

Longhorn release to manufacturing (RTM)
May 24, 2006



Longhorn Starter Edition
Analogous to Windows XP Starter Edition.

Longhorn Home Edition
Analogous to Windows XP Home Edition.

Longhorn Premium/Media Center Edition
A premium superset of Home Edition that includes the Media Center functionality. Similar to XP Media Center Edition.

Longhorn Professional Edition
Analogous to Windows XP Professional Edition.

Longhorn Small Business Edition
A new product edition aimed at the small business market. Currently very similar to Professional Edition.

Longhorn Mobility/Tablet PC Edition
Analogous to Windows XP Tablet PC Edition.

Longhorn "Uber" Edition
A new product edition that bridges the consumer and business versions and includes all of the features from the Home, Premium, Pro, Small Business, and Tablet PC Editions (but not Starter Edition).

[Unregistered]

Hello,

If you wish to recover lost partiton Active@ Partition Recovery tool is the choice. It has really great methods and will be able to help you in no time. Just give it a try.
http://www.partition-recovery.com/

[rkr]

on partitioning, does anybody know where I can get open partition software. dont have the money to buy a copy for one time use only... :)

[abudhu]

on partitioning, does anybody know where I can get open partition software. dont have the money to buy a copy for one time use only... :)

Hm, not sure about Open Partition Software, but when all else fails the Windows XP/any Linux OS/Mac OS Install CD's come with Partition Programs when you boot from CD.

If you are running XP you can also go to Start -- Control Panel -- Admin Tools -- Comp Management -- Disk Managment. From there you can play with the partitions. Though, if you want to expand and shrink partitions without losing data then you will need actual software.

The best Cost-Based Partitoner would be Partition Magic. Which can partition the drive after you install the OS and all that good stuff.

[rkr]

Cool, but Partition Magic is like $18.99, :( I tried the windows thing and it doesnt really work... I was trying to install linux on my PC and came across stuff that read like greek... so I ran away and quit...

[abudhu]

Like I said then, all Linux OS have Partion programs that come with them. You probably had to use FDisk? Anywho, what wrong with the Windows way? If you have 1 logical partition then you are out of luck partitioning through windows.

Google Fdisk Manual/Help/Instructions. I am sure the Linux distro you choose has a "how to install" for it as well.

[dparm]

A disgusting amount of info on FAT file systems:

http://en.wikipedia.org/wiki/FAT32


In short, Windows can only format up to 32GB on FAT32 (a strange choice by MS). FAT32 allows for up to 2TB.

Unless you need to swap hard drives between Windows and non-Windows OSes, you should use NTFS. NTFS support in non-MS OSes is limited. This is really the only downside. NTFS allows for larger file sizes, bigger physical drives, metadata support, better data structures (better performance), and offers security/encryption.

http://en.wikipedia.org/wiki/Ntfs

[Tony]

Ive got a problem here, ive got a digital video recorder, which uses 2 Hard drive, both formatted with FAT 32 but the hard drives are 160GB each, any ideas have i could format these as as you know windows xp doesnt let you do this?? any ideas anyone??
Got to be FAT 32 cause the machine doesnt reconise them as anything else...
Regards Tony

[dparm]

You need to use 3rd party software to create a partition larger than 32GB. Norton's PartitionMagic will let you do this. Otherwise you will need to use NTFS.