Supermicro JBOD question

[gdurham]

Hello all,
First time poster, long time reader. I am looking into doing a similar setup as referenced here I believe it was the ZFS Monster and several other builds. I am looking into using Western Digital 2TB RE4 drives and placing it in a SC847E26-RJBOD1 case. I just want to make sure that I can use standard sata disks not dual port sas disks with this case as it is the E26 and not the E16. (I know I won't get the multipathing, that is fine for this project) Also, would it make sense to use the LSI 9200-8e HBA with either of these JBODs?

This system will be used with Solaris 10 or perhaps Solaris 11 Express. My only other concern I have is with regards to the SES information so that I can get a port number when a disk fails, and perhaps flash the led.

Thanks,
Greg

 

[Astronot]

If you need an enterprise rated drive, HUA722020ALA330 should work, and is on Nexenta's HCL. With the recent bug fix firmware (P9) for that controller, it will work fine. HUA723020ALA640 drives are the successor to those, being SATA3 (both your controller and jbod expander support SATA3). You could also easily use the non-enterprise equivalent and not see any issues.

9200-8e will work, but needs the latest firmware.

Solaris 11 will work, not sure about Solaris 10 and sas2008 hbas. Good luck getting failure locations or working LEDs with anything except nexentastor. If you do, post back and let us know how you accomplished it.

 

[gdurham]

Thanks alot for the recommendation on that drive. I am looking into that sata 3 disk now. If I use this disk I will likely not run into the same issues that the person on the linked forum discussed correct? Out of curiousity, I have seen complaint over complaint regarding the intel sad disks. Are there as many issues with them as people talk about. I was looking at using x25e disks for the zil and x25m disks for the l2arc. Are there better recommendations or should I create another discussion altogether? Thanks again!

 

[packetboy]

Solaris 10 supports SAS2008 no problem.

There main thing you will give up if you go SATA instead of SAS drives:

* Half-duplex vs. Full-duplex

SATA is half-duplex only...so if you application consists of intense mix of read *and* write activity SAS drives would potentially double your throughput

There main thing you will give up if you go 3Gbps vs. 6Gbps drives:

* Controller to enclosure (effective) throughput

We have subsequently determined that the LSI expander in the SC847 does NOT support a feature known as multiplexing. The SC847 expander supports 6Gbps and the LSI 9200-8e also supports 6Gbps. And in fact, when you connect those two components together, the links between the controller and expander will indeed negotiate a 6Gbps link.

However, if you put a 3Gbps drive in the chassis, the *effective* throughput across the 6Gbps link will only be 3Gbps because of the expanders lack of support for multiplexing (the expander and controller will literally insert empty "frames?" for ever other frame)...

If instead you populate the chassis with 6Gbps SAS drives, you'll get the full benefit of 6Gbps chassis to controller uplinks.

Here's what I don't know:

LSI has only confirmed that you need 6Gbps SAS drives to resolve this......would using 6Gbps SATA drives result in the same dynamic (I would think so).

Secondly, what happens if you have a mix of 6Gbps and 3Gbps drives connected to a given expander? (e.g. do *all* the drives connected to an expander have to be 6Gbps to get the uplinks to work at full speed?).

If I were building a new setup right now, I'd be looking at the Generation 2 LSI 6Gbps HBAs...the ones based on the SAS 2308 chipset (e.g. LSI 9205-8e)...those are supposed to give you about 40% more IO capability than the SAS2008...however, I believe driver support only exists in Solaris 11-E for that (e.g. NOT Solaris 10)....plus haven't seen anyplace you can actually buy them yet.

 

[gdurham]

Thanks alot for responding. I am quite a fan of your setup. Do you see any differences with regards to the e26 vs the e16? I am thinking to use the sata 3 6gb/s disks that were recommended. I hope to get the needed bandwidth with this setup. Thanks again all!

 

[Astronot]

The second expander in the e26 is a failover, so it won't be active unless another path fails.

 

[ChrisBenn]

There main thing you will give up if you go SATA instead of SAS drives:
* Half-duplex vs. Full-duplex
SATA is half-duplex only...so if you application consists of intense mix of read *and* write activity SAS drives would potentially double your throughput

Just curious as to what kind of actual scaling you see with this in practice (with spinning disks) since the heads to a certain extent render the entire operation half-duplex?