Originally Posted by MikeSM
Hmm, that kind of CRC error is usually associated with a cable problem isn't it?
Yeah, both the CRC failure and the Bus Reset errors would indicate bad cables and/or backplanes - however the only difference between my setup with and without the Expander is ... the expander itself.
I'm using the exact same fanout cables to the drives, I've tried both input ports on the expander and all the different output ports.
I even opened another set of cables I had laying about so I've doublechecked all the fanout cables as well as the HBA -> Expander cable. Think that about covers all my bases apart from the Expander itself being bad which I somehow doubt as at least another member here is seeing similar errormessages.
I've emailed LSI, Supermicro and Chenbro now - hopefully one of them will get back to me with some info. Guess I should include Seagate on that list also, but I'm gonna try some other drives first, just have to finish shuffling the data off of them.---edit---
So, Supermicro got back to me via email already, saying;
I was seeing the specifications of the Chenbro Expander board and I did
not see any details on support for sata hdds. I am also saying this
based on our experience with expanders that the expander chip does not
go well with sata hdds. Can you confirm that your config of using sata
drives would work with the chenbro board by contacting them. Please let
me know your feedback on this.
This does fit in with what I've come across earlier, however I have another very similar setup that's working correctly. I've emailed Chenbro asking them to verify SATA compability though (even though they are using a LSI Expander IC which claims - afaik - SATA support and the Chenbro manual does state SAS/SATA compability).
Chenbro also got back to me, but so far they were rather useless as they were just pointing out;
For a best performance, below are recommanded RAID card model for very kindly reference.
1. Intel: SRCSASRB
2. LSI: MegaRAID SAS 8344ELP/8308ELP/84016E/8708ELP/8888ELP
So they obviously didn't read my entire support email. Obviously I emailed them back immediately asking for clarification as I am indeed using one of the "supported" LSI controllers (well sort of, the LSI IC on my board is the same as one of the supported ones - of course I didn't tell them I was using a OEM product
An interesting find though, I moved the firmware/bios jumper (it's now on the "old bios" setting) on the Expander and that seems to have helped somewhat. I'm still getting a bunch of errors, but read/write speed is tenfold what it was previous. It's still not fast by any means, with reads around 300MB/s and writes around 100MB/s (compared to, I believe, roughly 700MB/s RW when connected directly to the HBA) but it's usable - although the CRC errors are bothering me as I have a feeling it may cause issues should one of the drives actually go bad.---edit 2---
Chenbro got back to me again and after a lot of mailing back and forth this is the reply I got;
So at least they are acknowledging the problem. Now to see if we can come up with an actual fix I did some more playing around with settings yesterday and I'm now getting reads of around 700MB/s and instead of the flood of errors in the log I'm getting one or two every few minutes. Write speeds are still somewhat slow at 300-400MB/s (but it could be when I said RW 700MB/s that was the numbers for my 3Ware controller - can't be bothered to reconnect the drives directly to the HBA to do another test just now).
Thanks for your reply and information , after we have duplicated this issue again by testing in house , we got below result for your reference :
1. testing configuration :
- RAID card : LSI MegaRAID SAS 84016E w/ latest firmware version : 1.12.220-0560
- Chenbro SAS expander card : CK13601 rev A1
- SATA II HDD : we tested two models from Seagate
a. Barracuda 7200.10 (ST3750640AS) , SATAII 750GB
b. Barracuda 7200.11 (ST31000340NS) , SATAII 1TB
- Chenbro SAS/SATA II backplane ( 4 ports , for Chenbro rackmount chassis )
2. testing software : I/O mega
3. testing result :
for four ports , total performance can be up to rough 240 ~ 280 MB/s for each HDD model , thus , each HDD performance can be up to 60 ~ 70 MB/s (normal is around 50 MB/s) , though the whole system is still working fine without performance downgrade , we still get the similar WARNING MESSAGE from RAID card log file as well , but we think it is just warning instead of Error message to force HDD off line, we think it is kind of communication issue between expander card and RAID card , supposedly, it is not big issue for the system
4. check point for you :
- make sure the firmware setting jumper shall be on pin 1 and 2
- check LSI Mega RAID firmware on hand , and update if necessary
- check CK13601 w/Revision A1