I need a DAS solution

LaCie 2big running raid 0 running 6tb or, running raid 1 3tb. Backup to 3tb time capsule.

 

I don't think you get to say you're obsessed with performance unless you're willing to look at all angles, and by the sound if it your bias makes this a bit more neurotic. If you want speed, you get SSD. If you want capacity, you use NAS. If you want both you either take the risk with large fast RAID DAS, or go much safer with large fast 10GigE NAS like video professionals do. Half assing it is not exactly being obsessed with performance.

What does this mean? This is utterly useless unless the computer its connected to has the same thing. For DAS, you must have the computer and the DAS connected to a UPS. If you don't, and it's a large DAS, you have a high risk of corruption in case of power failure. You already have a high risk of file system corruption if there's a kernel panic. And on an iMac, which does not have ECC memory, it's inevitable you'll have a panic or other memory related data corruption which will find its way into the file system - just a matter of time. Could be minor, could be major.

Why?

 

Sound like a Synology 4- or 5-bay to me honestly.

Have a look at these charts:
http://www.synology.com/us/products/4-5bay_perf.php
Looks pretty fast to me.

Why do you care so much about how it's connected to your Mac? You can put it next to your Mac if you want to

 

I think they only make NAS.

But 100 MB/s is still too slow? Doesn't a single 3,5" HDD max out at around 120 MB/s ?

Sorry, I have no idea about USB3 SAN solutions. Maybe you can build your own server that holds your HDDs and connect it through Thunderbolt. Don't know if that's possible.

 

If the NEED usb3 or thunderbolt speed perhaps a Sohoraid would suit your needs. If you can handle gigabit Ethernet speeds (still faster then Firewire 800) a Synology 4 or 5 bay NAS is by far your best bet imo.

 

It uses ethernet (wired or wireless).

If you use wireless for internet, you can use an unused wired ethernet port with a regular ethernet cable and no hub/switch to connect to a NAS. It's still a network, it just appears to be direct attached. You in effect have two networks on a single computer, and this has been supported on Mac OS X for some time.

FWIW, 802.11/Airport is wireless ethernet.

 

Correct, so long as you don't have Internet Sharing (System Preferences > Sharing) enabled to bridge the two networks.

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Also, GigE is about as fast as FW800. However, there are faster solutions such as eSATA or Thunderbolt.

With an eSATA enclosure with a bunch of equal sized disks (say four of them), you can use Disk Utility RAID to create nested RAID such as 1+0 (a.k.a. RAID 10) to get speed plus mirroring. It's somewhat rudimentary but straightforward.

eSATA is faster than GigE, but you wouldn't have the features of a NAS. So it's useful to be really clear about what's important to your workflow.

 

Technically that would be DAS. Internally it's using the same aggregating logical volume management or RAID that a NAS does, but it offers an interface that provides block level access to storage.

NAS provides file level access using a file sharing protocol, not block level access (typically). A few NAS products offer block level access via iSCSI.

Block level access means no other computers can use a particular volume, i.e. not sharable, just like two computers can't share a single disk with eSATA. And you format such disks JHFS+/X on a Mac.

File level access means other computers can share, use a protocol like AFP, NFS or SMB. The underlying volume format is not JHFS+/X, it's usually a Linux file system like ext4, or XFS; or ZFS if it's FreeBSD or Solaris based.

Depends on the product. Usually DAS will not have ethernet ports, only USB or eSATA or FW or Thunderbolt. Usually NAS only only have an ethernet port, although it MIGHT have a USB port for the purpose of connecting a drive to the NAS for additional storage, NOT to connect it directly to a computer.

DAS+NAS products are typically more expensive, needing more sophisticated software to manage the different usages of storage.

Not sure. Usually this is integrated in Thunderbolt enclosures themselves.