I am looking at expanding my unraid server using an eSATA raid enclosure set as JBOD.

 

Something like this:  (this is an 8-bay, dual eSATA, there are also singe eSATA, 4-bay enclosures for $99)

http://www.newegg.com/Product/Product.aspx?Item=N82E16816111168

 

1.  Will this work!?

2.  Any issue with unraid eSATA support through a PCI-e 1x card?

3.  Performance of eSATA at 6.0Gbs seems more than capable of supporting many hard drives?

 

 

I started to reply in your other thread [user shares across 2 ...], but thought this thread was more on-topic.

 

[Disclaimer: this posting does not constitute an offer of ongoing assistance/advice (as explained below).]

 

Yes. 2 drives on an eSATA operate slower then 50MBps for parity checks but still bearable. Any more than 2 and parity checks, failed disk rebuilds, and failed disk emulation become too slow to be practical.

2 x 50MBps is pretty poor, but at least the port-multiplication is functioning. (Many people never get more than one drive active )

 

Let me add my own example. I have a Rocket 620A card (Marvell 9125 chip) in a PCIe x1v2 slot (lowly HP N40L) [i route a SATA-eSATA cable out the back] to a SansDigital TR4MB (SiI3726-based). With 4 drives in the TR4MB, and doing simultaneous sustained reads on all 4, I get 62-67 MiB/s on each drive. Thats a total sustained throughput of 260+ MiB/s (ie,272+ MB/s), seemingly limited by the SATA2 connection (the best the [old-timer] 3726 is capable of). [With 3 drives, or 2 [fast] drives, the same 260+ total.]

 

I don't run unRAID, but the above was on Linux (2.6.37). (Before you get excited note that after I upgraded to Linux 3.2.29, it stopped working entirely (I'll put the relevant old driver code in the newer kernel when I get around to it.) Just an example of the s**t that can happen.

 

The major caveat is that getting PMs to work well is totally unpredictable (exception being the SiI3132<=>SiI3726 combination, which is very stable, but slow--max bandwidth of ~140 MiB/s).

 

Personally => I <= won't recommend that anyone pursue port-multipliers, because then => I <= would be obligated to assist them in what may very likely be a futile endeavor. In other words, it's not only YMMV, but also PAYOR (proceed at your own risk ).

 

Damn shame too, because the concept, and at least some implementations, are fairly attractive. PM needs better OS support, and it definitely needs a "modernization". The most commonly-used PM chip is the SiI3726, which was released 8+ years ago! Some company needs to produce a SATA3-capable (4/5-drive) PM chip (that can really sustain ~550 MB/s) *AND* a PCIe x2/x4 controller that can cleanly interoperate with it (at max speed), *AND* offer solid driver support to make it all a useful reality.

 

Will we ever see it? ... Is hell gonna freeze over ?

[/rant]

 

 

I am going to leave port multiplication alone, and pursue other options, which is too bad.  Also too bad unraid doesn't support USB 3.0 yet, as that would be an excellent way to add a 4-drive array.

 

I found out after opening my case tonight that what I thought was a 2-hard drive caddy was actually a 3-hard drive caddy, so I have room for 1 more drive.  The option of adding a single external eSATA caddy off my mobo's eSATA cable gives me 1 more drive as well.

 

Is it possible to run an eSATA drive caddy off of an internal SATA cable?  If so then I could add additional drives that way.

 

And lastly, I could upgrade my 3 4-in-3 drive caddies to 5-in-3 drive caddies for an additional 3 drives.  (expensive though, at 3 x $75)

 

That, or upgrade to a Norco RPC-4224 24 drive case for $400 and be done with it!