How-To EXT3 format from Mac?

Hi, my Drobo is formatted for HFS+ (16TB) and I want to format it to use EXT3 (16TB). But via Dashboard on Mac and Drobo directly connected via USB I only can choose HFS+ or FAT32. Where is the EXT3 option?

And, will the EXT3 file-system handle the 16TB setup? I’m going to use the Drobo on Mac and Linux.

apparently you should not go above 2TB with ext3

As Docchris says for the standard Drobo the limit is 2TB - so you can have mulitple 2TB volumes but not a single 16TB volume when using ext3.

The DroboDashboard will only give an ext3 option if you are formatting a Drobo connected to a DroboShare. This is the only supported configuration for using ext3 - other configurations such as direct attached to linux are in beta. So they work but Data robotics don’t give any direct support on it.

I’m not aware of anything really easy or reliable for reading an ext3 volume on Mac OS X. You may be better off doing it the other way round - formatting to HFS+ which can be read on both Mac and Linux.

One thing to be aware of is that Linux can only write to a Non-Journaled HFS+ volume. This means that if you are moving between OS X and Linux you need to make sure that it is cleanly ejected from OS X (so the journal is empty) then mount on Linux with “rw,force” options to ignore the journal.
Without a journal you need to be aware that if the Drobo is not unmounted properly on Linux (e.g. OS crash or power outage) then there is a greater potential for data loss and you definitely need to check the volume is consistent (fsck).

I’m going to attach my Drobo directly to Linux. That’s why I don’t want to use HFS+.

Why is there a 2TB limit with EXT3?

Would it be possible to use EXT4 if the Drobo is attached to Linux via USB? I mean it looks like a normal big disk and Drobo should do all the “beyond raid” stuff fully transparent to the hardware and system.

EXT4: Ok, not possible as Drobo is filesystem aware.

I didn’t do this with Drobo, but to format a USB disk into ext3 from the Mac I used virtualization. I had a VMware Linux machine, “booted” that under VMware on the Mac, then attached the USB drive to that machine and formatted it there. If you don’t have VMware I’m sure VirtualBox will do it too.

There’s also a FUSE plugin that support ext2/3 as well, see http://sourceforge.net/projects/fuse-ext2/ for details. Not sure if it will let you format directly. I have NTFS-3G installed which is a similar plugin for NTFS filesystems and that one shows up as an option in Disk Utility, so the ext2/3 one might too.

I have a DroboShare, so no problem to get EXT3 up & running. I want to attach the Drobo to a Plug computer (see other thread) because DroboShare is to slow.

Hmm… Found this article that will hopefully help you choose…

Seems there’s still no universally-good option, but getting closer.