[Resolved] Attempted to add External SAS to server. Drives (or backplane?) not being detected in new configuration.

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PaperBlankets

New Member
Sep 6, 2019
12
1
3
Hi there, I attempted some updates to my server this weekend, and things didn't go as planned. I'm hoping someone will be able to spot a hardware incompatibility, or user error.

What I started with:
I have a CSE-846 with BPN-SAS3-846EL1 backplane that has been working well for a year or so.
LSI SAS9340-8i it mode in CSE-846 -> 1m Mini SAS HD SFF-8643 cable -> BPN-SAS3-846EL1 -> ** Drives

What I want to do:
I'm attempting to connect the backplane in my CSE-846 to another server I added to my rack/discontinue use of the motherboard/cpu in the CSE-846.

The configuration I wanted:
LSI SAS9340-8i it mode in 3u case -> 1m Mini SAS HD SFF-8643 cable ->Mini SAS HD SFF-8644 to Internal SAS HD SFF-8643 adapter -> External Mini SAS HD SFF-8644 to Mini SAS HD SFF-8643 2m cable -> BPN-SAS3-846EL1 in CSE-846/4u case -> ** Drives

Parts I have been using for a year/known to work/are working in my current configuration below:
New parts that may not work/I don't have redundant parts to rule out a failure:

What happens:
The LSI SAS9340-8i can't find any drives when running in the desired configuration above.

Current configuration:
LSI SAS9340-8i it mode in 3u case -> 1m Mini SAS HD SFF-8643 cable -> BPN-SAS3-846EL1 in CSE-846/4u case -> ** Drives.

The current configuration is very undesirable. I have to unrack the servers so the 1m cable reaches, the servers can't be moved.

Does anyone see a compatibility issue on the configuration I am attempting?
is 3m just too long of a run for SFF-8643/SFF-8644 cables?
This is my first time using SFF-8644 cables, I could just be doing it wrong somehow I suppose. The cable seems snug though/I have to release the clip to remove it.

Thanks for your time, let me know if you see anything I should try/have a suggestion on other hardware to get this setup working (I don't want to buy a new backplane/enclosure, but a new sas 12 card with it mode, alternate cables/adapters, let me know what you suggest and I will give it a shot).
 

j_h_o

Active Member
Apr 21, 2015
644
179
43
California, US
When I've had this problem in the past, it was because the SFF-8644 to SFF-8643 adapter wasn't wired/built to work on both the host and device side.

along with your Amazon link both say they're for host and device side -- you have exactly this adapter at this Amazon link?
 

PaperBlankets

New Member
Sep 6, 2019
12
1
3
When I've had this problem in the past, it was because the SFF-8644 to SFF-8643 adapter wasn't wired/built to work on both the host and device side.

along with your Amazon link both say they're for host and device side -- you have exactly this adapter at this Amazon link?
Yes I ordered this listing exactly: Amazon.com: CY Dual Ports Mini SAS HD SFF-8644 to Internal SAS HD SFF-8643 PCBA Female Adapter with Lowe Profile Standard Profile Bracket: Industrial & Scientific

It went "Currently unavailable" as soon as I ordered it which was a little suspicious to me.
It does visually look the same as the listing. I can post some photos if you suspect that adapter is the issue.


Edit: Thanks for your response @j_h_o, hearing it should work pushed me to try the final permutation of port combinations that got me a working connection.
Well, attempting every permutation of plug seems to have paid off.
The desired configuration is working when I use the second port on the adapter card.
I'm assuming the 8644 or 8643 connector on the adapter is faulty. It could also be the 8644 cable was not seated properly the previous 6 attempts I made (This cable does not seem to make a snug connection.). All this instability makes me uneasy. I'm thinking I should just pickup an external 12gbps sas card on ebay I would hate to rerack these servers just to find the drives are not detected when I reseat the 8644 cable in this sketchy adapter.
 
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