Hello Everyone,

I am trying to understand FILE SYSTEMS in UNIX/LINUX and WINDOWS.

jpollard wrote

REF_LINK : 1) Without file system cant we use any OS ? (windows/unix)
2) How file Systems are different from Cluster file system ?
3) Do we need any special license to use any available disk file systems/ ?

1) No. The OS needs to be installed on a filesystem, the installer won't proceed without creating one first.

3) Not for any that I'm aware of.

Have a look at these

https://en.wikipedia.org/wiki/File_system
https://en.wikipedia.org/wiki/Clustered_file_system
https://en.wikipedia.org/wiki/RAID
https://en.wikipedia.org/wiki/Logical_volume_management
https://en.wikipedia.org/wiki/Disk_partitioning

Probably more than you'll ever need to know!

2 members found this post helpful.

There are some cases in which you can use an OS without a file system, but I can't think of any that are useful to you, although I am guessing wildly at your use case in saying that.

There certainly have been filesystems for which people have had to pay license fees, but those people would not be you, and the cases in which this occurs probably would not be of any interest to you at the moment. If you stick with open source software, then you won't have license fees to pay, by definition, although you could use a filesystem (and/or filesystem driver) that required license fees, but it is entirely unclear why you should want to do this, particularly given that you have more choice than you can cope with already (probably).

I have seen some OS's that don't need a file system. Linux can use raw drives too but not as a boot that I know of. Might be able to use windows with a raw disk but it would take more time than it is worth.

It only depends on what boot loader you are using. Most of the boot loaders use some filesystem - but it is completely separate from the linux kernel. Once the kernel and initrd are loaded, the only filesystem used is the ramfs/tmpfs in memory only. And that can be sufficient for embedded use, or as a recovery system for device based filesystems.

It depends on the purpose of the system. Embedded systems tend to have very little to no filesystems in use. When the Linux kernel is used in embedded systems it usually comes with one or two filesystems - a cramfs read only filesystem compressed into a flash chip, it could come with an ISO9660 filesystems for CD/DVD boot, or just used for data (like a DVD player for instance).
Most such filesystems have to be network based (fibre channel/infiniband/... or slower with ethernet). These filesystems differ slightly in that access to the shared devices has to be managed - distributed locking or a central locking manager is necessary to prevent two systems from attempting to allocate/free/write the same storage blocks at the same time.
Depends on the system. To use Windows, you have to pay for a license (which includes the Microsoft filesystems). Most of Microsofts filesystems (FAT/VFAT/NTFS) have been independantly reimplemented that they are usable (changes to Windows has made it harder to use NTFS, as you can't safely use it unless you first shutdown Windows entirely - hibernation or whatever MS calls the "shutdown" currently does not dismount the filesystem, so using it will cause corruption of the filesystem). VFAT has elements that MS claims as patented... and shouldn't be used on Linux.