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Comment by cbd1984 | Hacker News Reader

cbd1984

OK, just so everyone is up to speed: Under what circumstances could a Linux filesystem be case-insensitive?

I know of three: FAT (specifically vfat, these days), JFS with Option -O, and CIOPFS (Case Insensitive On Purpose Filesystem):

http://superuser.com/questions/290480/case-insensitive-parti...

http://linux.die.net/man/8/mkfs.jfs

http://manpages.ubuntu.com/manpages/hardy/man8/jfs_mkfs.8.ht...

http://www.brain-dump.org/projects/ciopfs/

Are there any more?

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As for common filesystems (for some reasonable value of "common"): NTFS, HFS+ and SMB will probably be case insensitive. ZFS may be case insensitive.

There are others that would be exotic these days, like AFP. And with FUSE, could be anything.

My quick an dirty (pun intended) experiment concluded that ntfs, while mounted on linux, is case-sensitive. Windows will happily list all files from fs in explorer, whatever case they are, but treat them as one. And this is deep in win32: http://i.imgur.com/sWnCMdq.png (that's cygwin, while on linux, I've put a `small` file in the `test` dir).

You can mount NTFS case sensitive, but you probably don't want case sensitivity if you interop with Windows and, if you don't, why on earth would you use NTFS?

Yeah. NTFS is case preserving, not case sensitive.

NTFS is case sensitive. The Win32 layer presents NTFS as case preserving, but the NT POSIX layer (since renamed to SFU), as well as Cygwin, use NTFS's case sensitivity.

More to the point, the NTFS API can be both. And you can access that from Win32 code as well. There's also a registry flag to make NTFS case-sensitive by default.

Anyone knows what happens if an NTFS partition has both fiLe and file, when used in windows?

I just quickly tested this on Windows 7. It showed both a directory for both spelling, but both of them contained the same content corresponding to one of the two directories.

Re zfs, you have to turn case insensitivity off if you want it. The default is case sensitive.

That is: $ zfs get casesensitivity zroot NAME PROPERTY VALUE SOURCE zroot casesensitivity sensitive -

Is what you want in general. Unless you have some reason not to be, in which case you have to worry about the bug.

Probably a fairly common case: I use git on a Linux VM running in a Mac OS X host machine, using an NFS synced folder to share files between the host and guest. It appears that in this case the guest machine uses the case insensitivity of the host file system, making git vulnerable even though it's running on Linux.

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