esata extra drive

[mbu10]

ok just need a little info
just about to add a esata drive 750G into the back of the thecus
now what am i able to do with this
have a 5200
it is not currently formatted
will i be able to switch off and on as i will and the thecus pick it up when connected without a reboot
will i need to format from the thecus
would like to do back ups to the drive on a regular basis but lot of the files are 30 gig plus
any more info would be gratefully taken
thanks

[pit234a]

esata is something unknown to me, but because nobody else wants to answer, let me try.
You should been able to find documentation about your product and whether it could be plugged in “hot”, means with powered on System and connection. Let me assume, it will. Than the Use of such a device is as the Use of an USB device.
Your Linux Kernel will take care for a device, that is known and will produce the appropriate entry into a file(s) with the /dev directory.
Your busybox (the Unix in the N5200) can mount it than to any entry within the local directory tree, as usual within Unix environments.
With Linux, the kernel is also responsible to know about file systems. In other words, you always mount a file system, even when the command looks like mounting a device.
I am not sure, what file systems the Thecus people has build in their Linux, but I know that they can handle DOS and FAT and VFAT (FAT32) and even LARGE FAT32 and ext2, ext3 of course and also reiserfs. So, what does this mean for you?
In case, your device is hot-swappable, it will be detected and inspected by the kernel and a suitable entry in /dev will be generated, when the filesystem is known by the kernel. Than you are able to mount to any desired mountpoint with the desired options. The entry in /dev will be found automatically and as soon, as a device is found (also in runtime, not only at boot time).
In case, your device is not hot-swappable, the same is true, but you will have to switch the unit of before plug-in of the device. Than, you have a chance to get the device mounted automatically also, due to an entry in a /etc/fstab or due to actions given in a start-up script. In case, such a script is already used on the NAS, you will find your device mounted after reboot.

In both cases, you could also use a kind of automount daemon, that could mount a recognized device to a given mountpoint. This would mount your device automatically, even in the running system.

I prefer mounting manually.

So, you see, your question has two aspects:
First, the device must be recognized (hardware), than the file system must be recognized and this is done by the kernel without influence of a user and automatically, as soon as a device appears. dmesg gives you an idea about what the kernel is doing.
Second, a recognized device (partition) with known file system, that has got an appropriate entry in /dev, will have to be mounted to a mountpoint of your choice with the desired options (rw or ro ...). That you will have to perform your own, with or without the help of automatic tools.

In case of USB, the Thecus is mounting automatically and uses a mountpoint of the form:
/raid0/data/usbhdd/usb/sdf1
where sdf1 is the /dev entry, that was found for the device (sdf, 1 is partition one on this device). With other words: here you will not find the same mountpoint for the same device at all times, because the entries in /dev are counted high (first is /dev/sda than /dev/sdb and so on). So, this entry and thus the name for the mountpoint depends on the numbers of USB-devices that had been attached (USB is handled like SCSI, that is true for SATA also, so it is really found by the numbers of SCSI-like devices). In case the USB-device stays plugged in, it should be found with every boot with the same name, device count-number (or letter).
I would think this to be true for esata too, without any idea about the used mount point. You should however easy find this and figure it out.

As long, as a device has no file system established, it will not be mountable.
But you get an entry in /dev and dmesg shows you information, that you can use to create a file system on the device or something more. You could first add partitions (but it is not a must with Linux) and use fdisk to do that.
Fdisk shows also existing partition tables, as here: the internal CF-Card of the N5200:

# fdisk -l /dev/hda

Disk /dev/hda: 128 MB, 128188416 bytes
4 heads, 32 sectors/track, 1956 cylinders
Units = cylinders of 128 * 512 = 65536 bytes
Disk identifier: 0x00000000

Device Boot Start End Blocks Id System
/dev/hda1 * 1 32 2032 83 Linux
/dev/hda2 33 216 11776 83 Linux
/dev/hda3 217 705 31296 83 Linux
/dev/hda4 706 978 17472 5 Extended
/dev/hda5 706 859 9840 83 Linux
/dev/hda6 860 978 7600 83 Linux

(note that /dev/hd points to IDE hardware, /dev/sd to SCSI like hardware, as SATA and USB drives)

To create file systems, you can choose one of these on the box:
# ls /sbin | grep ^mk | grep fs
mke2fs*
mkfs.minix@
mkreiserfs*

oohps, even minix is known there!
You see, you cannot create something DOS-Style, because a tool like mkdosfs is missing on the Thecus (or it is on a different place, where I didn't find it (and busybox doesn't too)). But I know, because I tested, that FAT32 (and some of the rest of M$ File-systems) is known to Linux there.

So, you have a chance to set up a file system on the Thecus directly, but this is not as comfortable as with larger Systems like GNU, with their parted and such stuff. You don't have to do that with Thecus, you also could create those file systems and partitions on a different device, as your PC. Do not use NTFS, because of license stuff, it is not clearly supported in the world of free and be aware, that FAT may not use the same owner and right information, as used with Unix.
mke2fs also will build ext3 systems, they are ext2 plus journal, so they could also be changed later from ext2 to ext3 and for an external device, it might even be better without journal, depending on what you do with it.

You could than export the device (more precise: the mount point where the device is mounted) as usual and use this also for backup actions. Be aware once more: in case you used a M$ file system, it may reduce the maximum file size. Some do only 1GB, others 2GB or 4GB. To use files with 30GB size (what the hell is that? HDTV-Movie?) , you would need reiserfs or ext2 (or some other, but on the NAS only these would fit). As long as you want reach those files through the NAS, your other systems don't have to know about this file systems, the NAS will translate for them. But, when you want to use the disk directly on a different PC, this must been able to read (or write) this file system. Linux can easy access ext2 ext3 and reiserfs, FreeBSD not as easy and ext3 only as ext2, for M$, there would be some software, I was told.

http://www.busybox.net/downloads/BusyBox.html
gives an overview about the possibillities with busybox.