External HD file system

[JoelIT]

Hello,

Got Samba on fedora 13. Windows machines backup their files to the linux shared folder. I want to attach an external hard disk (USB) to the linux machine in order to backup those files. Can the external hard drive be NTFS or do I need to reformat it as Linux file system (ext3)?

Thanks,
Joel

[Irithori]

It can be ntfs, but I wouldnt recommend it.
a) it is slower, ntfs on linux takes quite a few cpu cycles
b) you cannot have posix users/permissions on it
Samba expects posix on its backend filesystem, so you would introduce more complexity with ntfs.

Other than that:
A usb2 drive is limited to 30MByte/s in the best case scenario.
Concurrent read/write operations will make it slower.

[JoelIT]

Thanks!

..so, you recommend ext3/4? What about restoring files to the Windows machines, would that be a problem (coming from ext3)?

Joel

[Irithori]

The files themselves -aka their content- probably not.
There might be issues with special chars in filenames, due to different charsets used on windows/linux.
So it would be good to have a filename convention in place, as in: no spaces, no special chars, all lower case, etc

If you also want to keep windows users/permissions, than that samba approach will not be sufficient.

You see, samba´s job is to map two mutual exclusive user/permission schemas.
Namely unix style against windows style.
So information is lost and replaced with "defaults", that are given by the adminsitrator in the samba configuration.


If you are interested in a serious backup system and not just copy over some files,
I would recommend Bacula, the Open Source, Enterprise ready, Network Backup Tool for Linux, Unix, and Windows
But this is a bit of a bigger project and may need some time to get used to.

[JoelIT]

-

If I'll stick to NTFS would it work (charsets,..)?
..and if so, the only down side is cpu/speed?

Thanks

[Irithori]

No,
then you will have yet another (possible) conversion in place.
- window clients sents files with windows users/permissions/charset
- samba server maps it to posix, using config defaults
- linux ntfs module maps it ntfs user/perms/charset, also using config defaults

If you want to go the samba route for backup and also rely on a usb disk as a backup medium, then I would recommend at least a linux filesystem (ext3) on the usb disk.

[JoelIT]

Let me try an example (excuse my ignorance )

Let's say that I have an "excel" file on the Windows machine and I back it up using Linux:

Windows -> Linux -> USB HD (ext3)

when restoring to Windows:

Windows <- Linux <- USB HD (ext3)

would the file come back the same or altered?

Thanks

[Irithori]

- The file content is the same.
- The filename *may* be altered, especially if special chars are involved. ie: äöüß or á'a etc
- the file permission and user/groups *will* be altered for the reasons outlined above

[JoelIT]

Got it, thanks.

How would FAT32 work in that scenario?

[Irithori]

Even worse.
- more limits on allowed chars and filename length
- file size limit of 4Gbyte
- no journaling
- no user/permission concept at all