Cluster Harddrive Using Firewire?

Ironstorm asks: "Recently I've started to see Firewire harddrives being sold from companies like Maxtor & Western Digital and now I'm pondering firewire storage solutions for high-availability clusters. Does anyone know if it would be possible to share a harddrive between two cluster nodes on a Firewire bus? Or have a node mount another node's Firewire drive if the other node has failed?"

Comments

Re:Of Course.

[Finni]

The link in the original question should answer your question. Mission-critical linux.

Their overview shows the original scenario he asked about, but with a SCSI bus or FC. All their downloads are for IA-32 Linux.

should work

[soldack]

In the fc/scsi world, you can send reserve, release, and reset signals. Server 1 goes down, server 2 trys reserve, if server 1 died too fast to release, reserve fails, server 2 resets ownership (blows reserve away), server 2 reserves, server 2 up and running with storage. I am not sure how firewire storage works (are the ops scsi like, the same fc ops are?), but I would geuss you would have something similar. Not it just depends if the host OS supports an application sending this ops accross. Then a cluster manager application can handle it. Perhaps the cluster manager needs to run at or in conjunction with some clustering device drivers but you get the picture. Should work...

Re:Drive lettering

[soldack]

NTFS and I believe FAT 32 (don't know about FAT 16) partitions retain memory of what their letter was. Win2k and NT4 will simply try that letter, if it is in use it will move up until it runs out. This keeps applications in line that reference the c: style notation. The problem is that c: is really just a symbolic link to a disk number and partition number. This link is not a UNIX one that is made through the file system but made at the device driver level.
The problem occurs when some software does not use a file system and does direct disk access. Some databases do this for example. This type of software usually does not use a drive lettered partition. It relies on disk and partition numbers and may or may not get broken when the numbering changes. Win2k disk and partition numbering is simpy based on discovery order. This in turn is based on the order in which drivers are loaded and where hardware is located on PCI and storage buses (SCSI/FibreChannel/FireWire). Put a new FibreChannel card in front of your old scsi and suddenly the database doesn't work. Write a special driver for you superduper disks that loads before the standard win2k driver and you may screw things up.
As others of noted Win2k supports mounting now. This lets you just have C as a sort of "/".
As for driver letters on firewire things should go like this in the win2k world:
PCI (if firewire pci card) or root bus driver (built into mother board) finds firewire bus, loads firewire bus driver.
Standard firewire bus driver finds device.
An additional driver or two will load some or all of which would be vendor specific. It could run like the standard scsi port driver/ vendor scsi miniport combonation. It would present an upword interface the same as presented by the normal scsi port/miniport combo but send firewire out the bottom.
This would let the standard pnp disk, partition, and file system drivers load on top.
They would talk scsi ops down the stack where the firewire scsi port/miniport would translate and encapsulate as needed and send it out, using the Firewire bus driver. Numbering occurs as things are discovered. Letters are assigned to partitions trying to use what was stored, moving up letters if a conflict occurs.

Peer-to-peer

[alannon]

A firewire network is not restricted to a single 'host'. Several computers can be plugged into a firewire network and share the peripherals on it. Similarly, the computers can communicate with each other as well. The only problem I can see is that only one computer can actually mount a drive at the same time. However, a system that would allow a second computer to mount a drive if the first failed should be trivial to implement.

Re:Drive lettering

[mbyte]

in NT (4.0 or 2000) you can directly assign letters to hard drives with the hard disk manager. I don't known if win9*/ME does honor these flags.

Re:Of Course.

[eightball]

How would you compose a sentence to say that a situation is not one thing, but is also not the opposite?

In this case, the poster could not imagine a negative result, but that does not mean he is capable of imagining universality of a positive. Although this might not be explicitly stated, it is usually assumed.

1. 'but, but, but he said he believed it : ('

Windows for one, still in the 'sucks department'

[eightball]

I have something of a SAN network set up at home, but it is not where I want it to be just yet. BTW, I am using ADS Pyro enclosures..

Of the os'es installed (latest {Free,Open}BSDs, Win2k and BeOS 5 pro) only the win2k server supports SBP-2, so it is the only machine able to mount them.

Even if another operating system could mount the drives, it would only be able to mount it read-only (assuming it could) since I am unable to get Win2k to mount these partitions as read-only. I am also unable to turn off the write cache, and since windows is not known for its stability, its an almost guarantee for scrambled data.(pointers desired if you have any)

Another thing I wonder about is direct node to node transfers. In theory, I should be able to transfer from one firewire device to another without going through a third party device (like a computer). Maybe the protocol does this automatically, maybe not, but it would be nice to use this for mirroring drives.

WARNING - meta-commentary ahead

[eightball]

I pre-apologize for the redundancy...

This is a reason that duplicate 'Ask Slashdot' columns happen. I have similar questions, I ask and nobody gets around to responding. I will grant that this is not much better than the original poster got.

This stuff could be the coolest consumer computer products in years, and yet /. as a whole spends more time dissecting whether preproduction "screenshots" from MSFT are ethical..

Anyway, I mostly posted this, so if I get to the point where I will have to 'Ask Slashdot' directly and get the obligatory "Dude, wasn't that question just asked this millenium?". I can then point them to my post to show that /. did not support conservation of bytes.

Re:Interesting...

[pheber]

I don't know about western / maxtor fw drives, but drives that spins faster than 5400 rpm needs a external power supply, drives that spin at 5400 can use the internal power from the firewire bus..
If your planning on carrying the drive around a lot, external powesupply is a pain in the ass..

Device Bay

[Animats]

There's a standard for hot-swappable FireWire based drives called Device Bay. A Device Bay slot has a blind mating connector that includes IEEE-1394, USB, and power. It's hot-pluggable. It's supported by Windows 2000, Intel, and Compaq. There's even a mechanical interlock to prevent users from unplugging a hard drive while it's active.

Nobody uses it. Apple, even though they use FireWire, is still into Little Boxes All Over The Table. Granite Microsystems sells some small Device Bay racks and a very few devices to put in them. As far as I know, nobody else actually has Device Bay products.

1394 - Ask for it by Number.
A (long, Flash-based) message from the 1394 trade association.

Re:Of Course.

[ajuda]

Get a life.


This message was encrypted with rot-26 cryptography.

Re:Of Course.

[ajuda]

Grammar nazi doesn't use perfect English.
Follow this link and observe his statement:
Isn't Bruce Willis believe in Scientology?

I guess that he hasn't been Keeping /. free of grammatical errors for 3 years.


This message was encrypted with rot-26 cryptography.

Re:Of Course.

[bellings]

"I can't imagine it wouldn't work" is bad grammer. Yeah! Yeah!

If you don't get the reference, you're a pretty shitty grammer nazi.

Of Course.

[bellings]

Yes. Dual hosting the SCSI bus to keep the storage available even if a node fails has been available for at least ten years, if not even longer. I can't possibly imagine that such wouldn't work with firewire, too.

Umm... wait. You are using VMS, right? Or do you want to give us some clue what kind of operating system and hardware you plan to use this on?

Re:Of Course.

[grammar nazi]

I hate to be a grammar nazi... ugh. Actually, I enjoy being a grammar nazi so much that I must point out that:
You shouldn't try not to use double negatives in no sentences!

We both know, bellings, that double negatives are awkward, so try and be a little more careful in your future posts.

Glad that I could help.

Re:Of Course.

[grammar nazi]

You are incorrect eightball. Our friend, bellings, stated, "I can't possibly imagine..." Since he said 'possibly', the opposite is necessary so. Hence, "I can neccessarily imagine...the opposite" is the proper sentence. Adding the necessarily makes the sentence a little more difficult to say, but it added because in Modal Logic you would add it.

Modal Logic is formal logic with the addition of "necessarily" and "possibly" in front of "true" and "false" (WARNING: simplistic definition).

Drive lettering

[brad3378]

Okay...
Slightly off topic

How does windows assign drive letters to these drives? My "cold swap" pullout IDE drives require a reboot (in win 9x/nt/2k ) so the drive letters can be assigned. Even worse, the drive letters change on my Primary Master drive when I add/remove my secondary Slave drive.

FYI, Linux doesn't require a reboot as long as a hard drive was detected on bootup. And obviously drive letters & Mount points are not a problem.

Does windows require some add on software for Firewire Drives? Or will it simply just add a drive letter for each partition.

Anybody care to share their 2&cent?

Re:Drive lettering

[bonzoesc]

It can't - my /dev/hda0 partition is NTFS, and 9x doesn't have its' partition until way the hell out on /dev/hda6. If it followed the flags, it would not find a C: drive, since 9x can't mount NTFS. It would also not be able to find itself because it looks for itself on drive C.

9x follows its own queer way of assigning drive letters: /dev/hda1, if FAT, gets C:; /dev/hdb1, if FAT, gets D:; /dev/hdc1, if FAT, gets E:; /dev/hdd1, if FAT, gets F:; (here's where it gets gay) /dev/hda2, if FAT, gets G:. The first partition on a drive gets a drive letter before the second partition on the first drive.

Tell me what makes you so afraid
Of all those people you say you hate

Re:Drive lettering

[ffsnjb]

Someday, MS will find that drive lettering is the most retarded way of mounting drives, and will switch to the good way. If only I could add more space to c:\windows as their os gets more bloated...

"mount /dev/ad3s1e /home/ffsnjb/morespace" works real well for this, but only under a real OS...

Re:Drive lettering

[ffsnjb]

Then I guess MS has seen the light? I haven't played with 2k enough to find this stuff out, as the only 2k machine I have access to is a q3a server that I'm hosting with only a single 3 gig drive. The machine is unstable as all hell and needs to be rebooted daily, but this is probably a messed up install by the box's owner. No wonder he wants me to wipe the drive and put a real OS on it.

I refuse to ever install any MS software ever again, because, imho, it fucking sucks.

No Windows for this server...

Re:Drive lettering

[wbmccrea]

Just thought that I should mention it, but Win2k doesn't need to use drive letters for anything other than the "root" drive (c:\). Win2k also lets you mount a partition to a path, AND assign a drive letter to it (but I really don't see why you'd want to do that). IIRC this feature has been in win2k since NT 5.0 Beta 2 (that was the first win2k beta that I played with.)

Interesting...

[JediTrainer]

I thought it'd be interesting to note that ALL of the Western Digital Firewire hard drives run at 5400 RPM.

How come they're spinning so slow? I'd thought that they would have them running at 10 or 15k!

I couldn't find the specs on the Maxtor drives...

NO

[JediTrainer]

Apparently, according to Maxtor (skip to Q-17), sharing of devices between multiple computers is not an available ability.