RAID2 Over TCP/IP? 9
Cheeze asks: "I was wondering if there are any working implementations of RAID2 over TCP/IP. This would be a logical solution to high availability and data redundancy. The ability to have two identical mirrored separate machines with identical data stored on them would almost remove the risk of a hardware failure. I haven't heard or seen any documentation on this, but it should be relatively easily. On a high bandwidth (>=100Mbps) private switched network, there should be no problem with keeping the bandwidth up to par with the hard drive transfer speeds. a software solution would be practical, but a hardware solution would be optimal. Any ideas or possible future projects on this topic?" Is such a thing practicle, or even possible?
Isn't this what NAS is all about? (Score:1)
The Network Block Device (Score:1)
From the article - A network block device (NBD) driver makes a remote resource look like a local device in Linux, allowing a cheap and safe real-time mirror to be constructed.
Re:Isn't this what NAS is all about? (Score:1)
How about clustering and DB replication? (Score:1)
This can also be accomplished with shared disks and OS failover solutions like IBM's HACMP, but I think you were looking for something that didn't require shared hardware.
I don't know of anything similar for filesystems; databases naturally have a transaction model which provides atomic updates, guaranteeing against data loss. Implementing something similar at the filesystem level would probably take some serious kernel hacking.
On the other hand, distributed filesystems like Coda, GFS, AFS, etc. might have failover capabilities.
Veritas Storage Replicator (Score:1)
Are you sure that's what you want? (Score:1)
Re: (Score:2)
Not that hard, really.. (Score:2)
I don't know how usable it would be over even a pipe as fat as that, but you could technically use a dual-volume replicated RAID, with each machine obtaining one volume from the other.
Make a file as large as the desired dynamic portion of the filesystem on each, export it via NFS/SMB/etc.Each mounts the others export,
On drive failure, the remaining machine shouldn't skip a beat, aside from an initial timeout. The kernel should handle it gracefully (but cluelessly).
Now how you would go about automating and easing the 'server repaired' condition is left for a reader exercise.
(read: I don't have a clue how you'd do it. )
Re:The Network Block Device (Score:2)