Very Slow Parity Rebuild, Config Issue?


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Hi,

 

I am wondering if I am not using my devices at optimily as I could? I am getting such terrible speeds and really think things should be better!

 

I am getting a parity build speed of approx 9-10 mb/s with the occasional 40-50mb/s

 

I have the following hardware.

 

M/B: Gigabyte Technology Co., Ltd. X399 DESIGNARE EX-CF Version x.x - s/n: Default string

BIOS: American Megatrends Inc. Version F12g. Dated: 05/08/2019

CPU: AMD Ryzen Threadripper 2950X 16-Core @ 3500 MHz

HVM: Enabled

IOMMU: Enabled

Cache: 1536 KiB, 8192 KiB, 32768 KiB

Memory: 48 GiB DDR4 (max. installable capacity 512 GiB)

Network: bond0: transmit load balancing, mtu 1500
 eth0: 1000 Mbps, full duplex, mtu 1500
 eth1: interface down
 eth2: 10000 Mbps, full duplex, mtu 9000

Kernel: Linux 4.19.98-Unraid x86_64

OpenSSL: 1.1.1d

 

Port 1 of my SAS3008 12gb/s card goes to 4 drives (including Parity Disk) but ALL drives are connected via a 6gb/s Backplane

The rest are either connected via the Dell RES2SV240 or the motherboard SATA But all drives are connected via the 6gb/s Backplane.

 

[0:0:0:0]disk PNY Tech USB 2.0 FD 1100 /dev/sda 4.05GB                     ---- USB With unRAID

[2:0:0:0]disk ATA ST3500312CS SC13 /dev/sdi 500GB                          ---- Motherboard SATA

[4:0:0:0]disk ATA SAMSUNG HD204UI 0001 /dev/sdw 2.00TB                ---- Motherboard SATA

[6:0:0:0]disk ATA SAMSUNG HD204UI 0001 /dev/sdx 2.00TB                 ---- Motherboard SATA

[8:0:0:0]disk ATA TOSHIBA HDWD130 ACF0 /dev/sdy 3.00TB                 ---- Dell RES2SV240 Extender Port 2 of SAS3008

[11:0:0:0]disk HGST HUS726060AL5210 AD05 /dev/sdb 6.00TB             ---- Dell RES2SV240 Extender Port 1 of SAS3008

[11:0:1:0]disk SEAGATE ST6000NM0095 E004 /dev/sdc 6.00TB             ---- Dell RES2SV240 Extender Port 1 of SAS3008

[11:0:2:0]disk ATA ST6000NM0115-1YZ SN04 /dev/sdd 6.00TB                ---- Dell RES2SV240 Extender Port 1 of SAS3008

[11:0:3:0]disk HGST HUS726060AL5210 AD05 /dev/sde 6.00TB            ---- Dell RES2SV240 Extender Port 1 of SAS3008

[11:0:4:0]disk ATA ST6000VN0033-2EE SC60 /dev/sdf 6.00TB               ---- Dell RES2SV240 Extender Port 2 of SAS3008 

[11:0:5:0]disk ATA ST6000DM004-2EH1 DN03 /dev/sdg 6.00TB              ---- Dell RES2SV240 Extender Port 2 of SAS3008

[11:0:6:0]disk ATA ST6000DM003-2CY1 0001 /dev/sdh 6.00TB               ---- Dell RES2SV240 Extender Port 2 of SAS3008

[11:0:7:0]disk ATA ST2000DL004 HD20 0001 /dev/sdj 2.00TB                ---- Dell RES2SV240 Extender Port 2 of SAS3008

[11:0:8:0]disk ATA ST3000DM008-2DM1 CC26 /dev/sdk 3.00TB              ---- Dell RES2SV240 Extender Port 2 of SAS3008

[11:0:9:0]disk ATA TOSHIBA HDWD130 ACF0 /dev/sdl 3.00TB                  ---- Dell RES2SV240 Extender Port 2 of SAS3008

[11:0:10:0]disk ATA TOSHIBA HDWD130 ACF0 /dev/sdm 3.00TB              ---- Dell RES2SV240 Extender Port 2 of SAS3008

[11:0:11:0]disk ATA TOSHIBA HDWD130 ACF0 /dev/sdn 3.00TB               ---- Dell RES2SV240 Extender Port 2 of SAS3008

[11:0:12:0]disk ATA TOSHIBA HDWD130 ACF0 /dev/sdo 3.00TB               ---- Dell RES2SV240 Extender Port 2 of SAS3008

[11:0:13:0]disk ATA TOSHIBA HDWD130 ACF0 /dev/sdp 3.00TB               ---- Dell RES2SV240 Extender Port 2 of SAS3008

[11:0:14:0]disk ATA TOSHIBA HDWD130 ACF0 /dev/sdq 3.00TB               ---- Dell RES2SV240 Extender Port 2 of SAS3008

[11:0:15:0]disk ATA SAMSUNG HD204UI 0001 /dev/sdr 2.00TB                ---- Dell RES2SV240 Extender Port 2 of SAS3008

[11:0:16:0]disk ATA WDC WD30EFRX-68E 0A82 /dev/sds 3.00TB            ---- Dell RES2SV240 Extender Port 2 of SAS3008

[11:0:17:0]disk ATA ST1000DX001-1CM1 CC43 /dev/sdt 1.00TB                -NOT PART OF ARRAY

[11:0:18:0]disk ATA TOSHIBA HDWD110 A8J0 /dev/sdu 1.00TB                -NOT PART OF ARRAY

[11:0:19:0]disk ATA ST3000DM008-2DM1 CC26 /dev/sdv 3.00TB            ---- Dell RES2SV240 Extender Port 2 of SAS3008

[N:0:4:1]disk Samsung SSD 970 EVO Plus 1TB__1 /dev/nvme0n1 1.00TB  - CACHE DRIVE    

 

The parity disk is one of 4 drives connected to one of the ports of my sas3008 pci SAS controller

 

Would I be better to connect all drives on 1 port of the sas card going through the dell extender? My thinking was that one port to host the parity and 3 other drives would help speed?

 

Any advice greatly appreciated! 

 

 

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Hi just thought I would bump this as the parity took 4 days to complete and this used to take a day at most! I have seen my speeds drop from 150mb/s to 9-15mb/s for parity.

 

I have noticed my system is generally very sluggish, sometimes waiting 10 seconds or so for a response even thought the drives are all spun up and being on a 10gb/E fibre connection. 

 

Any recommendations please?

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thanks for your reply, "unfortunately" the parity rebuild has finished, it made my system so slow I do not want to start another rebuild for another 4 days, is there any other way I can provide something without rebuilding parity or can I just start a parity check, grab the diags and cancel?

 

Thank you

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1 hour ago, mbc0 said:

Can I ask what you think about the way I have connected things and if you think I can make any improvements there please?

Though that's not the issue here if you connected both cables from the HBA to the expander it would be better for performance, but it would limit you to 16 ports.

  • Like 1
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Thanks for the reply, 

 

I will reboot tonight but firstly connect both cables to the HBA as I do not require all 24 ports currently.  Also I use the mainboard sata ports through a reverse cable to the backplane to run SSD Drives, would that be ok or even neccassary? 

 

Thank you for your advice!

Edited by mbc0
spelling
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Hi @johnnie.black I have now connected both cables from the SAS3008 to the RES2SV240 as recommended and used 2 reverse breakout cables from the 8 on-board SATA motherboard ports to the other 8 bays on the backplane so all 24 bays are active 🙂 

 

Is there a way of ensuring that both connections are active from the SAS3008 as I only had 1 extra cable to connect from the SAS3008 to the RES2SV240 and was not 100% sure if it is functioning correctly and would order a new one if I could find a way of telling?

 

Many Thanks Again 🙂

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Hi @johnnie.black

 

I hope you, your friends and family are safe and well during this pandemic 😞 I like most of the world am in lockdown so finding more time to work on my server so I have attached some diagnostics when my server literally ground to a halt whilst copying some data and if you get a chance wonder if you can look through it to see what can be causing the issue.

 

Many Many Thanks

unraidserver-diagnostics-20200325-0116.zip

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Did you just un-pause it? Elapsed time is less than a minute, stats need to stabilized, according to diags it's going close to 50MB/s, which seems about right since it's reaching the slower inner sectors of the 2TB disks.

 

You can also try the diskspeed docker, there might be one more more disks under performing.

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Hi, yes I did just unpause it, I am keeping it paused as I started moving data from disk to disk yesterday morning to allow me to create some redundant disks but my disk to disk performance is painfully slow as well.  once this has completed I will restart the parity leave it for an hour and take another diag. 

 

Thank you

 

 

Annotation 2020-04-01 120027.jpg

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