Imaging SAS drives

As for the previous posting, there appears to be a bit of confusion. SAS is backwards compatible with SATA 2, but not the other way around; SAS drives cannot be interfaced to a SATA backplane.

Good )
http//serialstoragewire.net/Articles/2007_07/itinsights24.html
http//www.dslreports.com/forum/r18202209-SAS-to-SATA-Convert

So the device is just a "gender-changer" or "pinout adapter" of some kind and does not "convert" anything.

These adapters appear to convert a host sas controller to sata. For it to work as suggested it I think it would have to convert host sata to sas.

Regards Richard

i.e. it is another version of this
http//www.techcable.com/HTML/SAS-SATA.htm

292704-XXXXMM

but then what is the use of the electronic components on the board?
To "separate the channels" and allow this Active-Active mode?

Now this is interesting
http//www.intelforums.net/showthread.php?t=456396
(check the actual replies of tech service) roll

I guess that the words "adapter" and "converter" could be used with a little more attention, expecially when talking of technical matters….

jaclaz

I don't wish to be discourteous but I still believe a SAS hba is required and that the suggestion that this backplane will somehow convert a sata hba to enable sas support is spurious.

If it saves me money, you can be as discourteous as you wish. lol

Or, if you prefer, WHAT would be the use of such an adapter?

SAS controllers were designed to be backwards compatible with SATA 2. Not the other way around. The adapter is marketed as a way to make SAS drives hot swappable. Nowhere does it state that it will allow them to be controller with a SATA controller.

Moreover, the eBay add states

2 SATA connector, one is marked as Signal-Primary and another is marked as Signal-Secondary. Connect them separately to different SAS HBA/RAID card to achieve Active-Active mode.

This particular card takes advantage of the fact that the SAS spec allows SATA 7-pin interfaces for the data channel (again, this was to allow a SAS controller to use less expensive SATA drives).

Manufacturers understood that the incremental cost of putting a SAS interface instead of a SATA interface on a server motherboard was practically nothing but the drives were more expensive so they made the interfaces compatible with both SATA 2 and SAS. SATA controllers, on the other hand, will interface only to SATA drives.

Interestingly, nowhere does the manufacturer say otherwise yet the advertising is cleverly vague.

As for the previous posting, there appears to be a bit of confusion. SAS is backwards compatible with SATA 2, but not the other way around; SAS drives cannot be interfaced to a SATA backplane.

Good )
http//serialstoragewire.net/Articles/2007_07/itinsights24.html
http//www.dslreports.com/forum/r18202209-SAS-to-SATA-Convert

So the device is just a "gender-changer" or "pinout adapter" of some kind and does not "convert" anything.

These adapters appear to convert a host sas controller to sata. For it to work as suggested it I think it would have to convert host sata to sas.

Regards Richard

i.e. it is another version of this
http//www.techcable.com/HTML/SAS-SATA.htm

292704-XXXXMM

but then what is the use of the electronic components on the board?
To "separate the channels" and allow this Active-Active mode?

Now this is interesting
http//www.intelforums.net/showthread.php?t=456396
(check the actual replies of tech service) roll

I guess that the words "adapter" and "converter" could be used with a little more attention, expecially when talking of technical matters….

jaclaz

Jaclaz,

In this post you attribute a quote to me (the first one) when in fact you are quoting seanmcl who I think holds the same view as me.

I was simply trying to assist, I am struggling to follow the multiple links in your last post. Are you still saying that the card will allow the connection of a Sas hdd to a sata controller?

Regards

This topic has come up on a few forums and Twitter. I reached out to Tableau/Guidance regarding their planned release of a SAS bridge

We are working on a SAS product, but I’m uncertain when it will be released. Our hope is to release it this year, but I’m not sure when.

If you’d like to be notified when we release new products, feel free to either subscribe to our “New Products” list on our website, our twitter page, or our RSS feed.

So it's in the works…

We are working on a SAS product, but I’m uncertain when it will be released. Our hope is to release it this year, but I’m not sure when.

I think that this underscores the difficulty of bridging SAS drives to USB/SATA controllers. If it were really possible to do this with a product that costs under $7, it would have been done by now.

Given how inexpensive SAS controller cards are, it would make more sense to get a SAS write blocker to market and worry about a bridge down the line.

The same goes for SATA 6G and USB 3.0, IMHO.

Jaclaz,

In this post you attribute a quote to me (the first one) when in fact you are quoting seanmcl who I think holds the same view as me.

I was simply trying to assist, I am struggling to follow the multiple links in your last post. Are you still saying that the card will allow the connection of a Sas hdd to a sata controller?

Regards

Sorry for the mis-quote. cry

What I said is that that board has nothing to do with the "host" side (which is what I got from your post) and is to be put behind the actual SAS hard disk (as per photo's on the producer site).

I do know that direct hooking of a SAS drive to a SATA controller is not possible, and from the original post by JDCoulthard I had gathered that this is actually a "converter", which it seems like it is not.

This is the missing link oops
http//www.dslreports.com/forum/r18202209-SAS-to-SATA-Convert
which contains an e-mail of the actual producers, that is NOT clear, to show how probably OP was tricked into thinking that it was a converter.

To clarify my view, this
http//www.addonics.com/products/flash_memory_reader/ad44midecf.asp
is an "adapter"
and these
http//www.addonics.com/products/io/adideu2.asp
http//www.addonics.com/products/io/ide_sata.asp
are "converters"

So, it seems that this thingy is an "adapter" and NOT a "converter" and thus it "adapts" and it does NOT "convert".

This is the sentence where the misunderstanding started

These adapters appear to convert a host sas controller to sata. For it to work as suggested it I think it would have to convert host sata to sas.

You are right ) , this thingy won't do.

You expressed this righteous fact with words that I failed to understand and that are likely to confuse people, and it seems like even the actual producers of the thingy did NOT produce a clear explanation.

jaclaz