Hi Ashish! Also give us details of the make, cost and place of purchse, warranty etc. so that someone else in future wanting such a thing would look this info up from ur mail or atleast remember reading about it.
I have a 80GB USB hard disk that I use exclusively for data storage. It was given as a raw disk to me and I formatted it as FAT32 single partition. Later I wanted to store the ISO images of distros that I come across in it and FAT32 proved to be a handicapped file system (I could not store more than 4GB per file. Thats the limit in FAT), so I formatted it as EXT3 using PartitionMagic without loss of data. Though I could not use that from my Windows partitions, I never had any issues as I hardly work with Windows. Ofcouse, now I use the DiskInternals EXT2 reader (read-only) to read it from Windows. Now I doubt if you would want a 400GB single partition, but I guess you can, theoritically, have a FAT partition in it. But stay initiated that you can't store a file which is bigger than 4GB. If indeed you want to store large files you may use an EXT3 partition. I would still like to go for a single partition and sort my data in directories instead of multiple partitions to store different types of data. Regards, -- Navneet Sreeraman

