Slower performance with newly added drive.

[mattm1121]

Greetings,

 

I currently have the following set up with UnRaid 6.10.3;

Parity    WDC_WD121KFBX-68EF5N0_5QK0K9KB - 12 TB (sdi)

Disk 1    TOSHIBA_HDWG11A_Z1L0A021FBDG - 10 TB (sdl)

Disk 2    WDC_WD102KFBX-68M95N0_VCKR49BP - 10 TB (sdj)

Disk 3    WDC_WD102KFBX-68M95N0_VCKW15MP - 10 TB (sdk)

 

During parity checks or certain other operations, the read/write values average around 230mb/s. Parity checks take around 18 hours to complete with an average of 180mb/s according to the history.

 

I purchased two 12tb drives. (Western Digital 12TB WD Red Plus NAS Internal Hard Drive HDD - 7200 RPM, SATA 6 GB/s, CMR, 512 MB Cache, 3.5" - WD120EFBX)

 

I pre-cleared one and added it to the raid. The other I use as to backup data. Once added the parity check took 30+ hours with an average of 114mb/s. 

 

So my question would be does it take longer the more drives you add? Is this type of performance change expected?

 

I appreciate any feedback anybody has. 

 

Thanks.

 

toph-diagnostics-20221004-0625.zip

Edited October 4, 2022 by mattm1121

[JorgeB]

Please post the diagnostics, mostly so we can the hardware.

[mattm1121]

Added. Sorry about that. 

[trurl]

 

[JorgeB]

Hardware seems capable enough, though there might be a bottleneck if you have the HBA installed in the bottom slot, running a diskspeed test is a good idea to test disk speed and controller bandwidth.

[jbartlett]

http://strangejourney.net/hddb/index.cfm?View=Drives&Vendor=Western Digital&Model=WD120EFBX

 

The tail end of the drive is kinda slow IMHO but the overall average is around 170mb/sec. Compare your graph to the ones in the link, the data sample is still small but out of 7 unique drives uploaded, the spread is pretty tight.