Hi All,

 

I have always noticed that when running Parity Sync or Data Rebuild on my server, it is quite slow.

 

I am currently running a data rebuild on a 3TB drive (Hitachi HDS5C3030ALA630), and it is running at 26 MB/sec.

 

Please, is there something I need to do or changes I need to make on my server so that Parity Sync/Data Rebuild doesn't take so long to run.

 

Thanks,
T

tower-diagnostics-20181202-1614.zip

Edited December 2, 20187 yr by tboggie

Your two SASLP-MV8 controllers are likely to be the bottleneck, having eight disks each and a slow PCIe interface. I don't see any evidence of the usual problems associated with these Marvell-based controllers, renegotiating SATA links and dropping disks, though, which is the reason that many people have replaced theirs with LSI-based HBAs. Have a look at this thread for some suggestions - the tunables make a big difference:

 

 

Thank you. I'll go through the thread.

 

Any suggestions on getting two of these LSI-SAS-9207-8i controllers to replace the SASLP-MV8 controllers?

 

Try this one that's actually in stock. It's a nice card that works out of the box. If you want to spend less, get a pair of Dell Perc H310s from Ebay. Second-hand server pulls are cheap but you'll have to cross-flash them to LSI/Broadcom IT firmware, which a number of people have found more difficult than it really ought to be.

Like mentioned, the SASLP is not the fastest controller, but they are good for 80MB/s with all ports in use, your main issue is:

 

Dec  2 13:04:05 Tower kernel: mvsas 0000:01:00.0: mvsas: PCI-E x1, Bandwidth Usage: 2.5 Gbps

One of them is on a PICe x1 slot (or it's only linking at that speed), if the same happens to the LSI the speed will be better since it's PCIe 2.0, but still much slower than it should be.

Thanks. I've ordered two LSI SAS9207-8i cards from ebay.

 

 

 

 

Update.

So I received both LSI SAS9207-8i controllers today and straight away replaced both controllers on the server.

After starting the server, I noticed on the dashboard that 8 drives we missing i.e. 8 drives linked to one of the cards. I then swapped the LSI SAS9207-8i cards around to see it was a problem with one of the cards, and saw the same issue. Next, I replaced one of the cards with the old SASLP-MV8 card and placed in the PCIx4 slot, and to my surprise, all drives were green. I then swapped the cards around i.e placed the SASLP-MV8 in the PCIx16 slot and LSI SAS9207-8i in the PCIx4 slot, and again 8 drives were red. I then replaced the LSI SAS9207-8i card with the other to confirm if the problem was with the controller, but result was the same -  8 drives were missing.

 

Lastly, I placed the SASLP-MV8 in the PCIx4 slot and LSI SAS9207-8i in the PCIx16 slot and as before, all drives were green which makes me conclude the problem might be with LSI SAS9207-8i cards on the PCIx4 slot. 

 

Please is there anything i can do to get this to work? I have attached the logs.

 

Good news is that I started a data rebuild on a 3TB drive to check the parity speed and i'm seeing 84 MB/sec, which is way better than before. 

 

Thanks,

T

 

 

 

tower-diagnostics-20181205-1212.zip

11 minutes ago, tboggie said:

Please is there anything i can do to get this to work? I have attached the logs.

Only one LSI is being detected, look for a bios update, if that doesn't help a new board is likely the only solution.

 

12 minutes ago, tboggie said:

Good news is that I started a data rebuild on a 3TB drive to check the parity speed and i'm seeing 84 MB/sec, which is way better than before. 

Likely the SASLP is now linking @ x4 like it should, instead of x1 like it was.

On 12/5/2018 at 3:18 PM, johnnie.black said:

Only one LSI is being detected, look for a bios update, if that doesn't help a new board is likely the only solution.

Found the latest BIOS update, flashed the BIOS successfully, with both LSI cards connected the motherboard, started the server and dashboard shows all drives are green. Started a parity check and now I am seeing 100 MB/sec

 

Thanks for your help.