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crookedview

Poor SHR performance vs single-disk

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I'm running Xpenology in a VMWare 6 ESXi environment with an IBM m1015 RAID controller flashed to LSI firmware in IT (HBA) mode. I have 2 disks (4TB) attached to the controller that are running as Synology Hybrid Raid (SHR) and a single disk (5TB) also attached to the controller that is running in single-disk mode.

 

My read speeds from the SHR configuration are between 80-110MB/s, while the single disk read speeds are usually >110MB/s read speed.

 

Is there something in Xpenology that I can tweak to achieve better SHR read speeds? I thought RAID1 read speeds would be much higher than what I'm getting.

 

I should mention I'm using XPEnoboot 5592.2.

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Did you set up RAID1 (redundancy)? This doesn't give you any speed advantage compared to a single drive.

 

RAID1 = mirroring of 2 (or more disk)

 

There are only 2 choices for a RAID setup when you have 2 drives: RAID0 (striping, this is where you would get more speed at the risk of a total data loss if only one drive crashes) or RAID1.

 

Speed and safety would be RAID10 (which are two RAID0, mirrored) but you would need more disks (minimum 4).

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SHR with only 2 disks is in security mode similar to mirror

 

The speed is the same with only one disk

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crookedview, if you really need need higher speed for IO operation you can use PCI HBA controller like LSI 9211 or LSI 9207.

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hum ..

 

regardless whether the card controller disk speed remains unchanged

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SHR with only 2 disks is in security mode similar to mirror

 

The speed is the same with only one disk

 

My speeds aren't the same, though :sad:. The single disk is faster than the 2-disk SHR array.

 

crookedview, if you really need need higher speed for IO operation you can use PCI HBA controller like LSI 9211 or LSI 9207.

 

I am using a PCIe controller (m1015 flashed to LSI firmware). All 3 drives (2 SHR 1 single disk) are connected to this controller.

 

Did you set up RAID1 (redundancy)? This doesn't give you any speed advantage compared to a single drive.

 

RAID1 = mirroring of 2 (or more disk)

 

There are only 2 choices for a RAID setup when you have 2 drives: RAID0 (striping, this is where you would get more speed at the risk of a total data loss if only one drive crashes) or RAID1.

 

Speed and safety would be RAID10 (which are two RAID0, mirrored) but you would need more disks (minimum 4).

 

Yeah andale, I set up SHR for 2 disks, which from what I read sets the drives up in a RAID 1 array. I was hoping that SHR would perform striped reads between disks (ZFS will stripe reads across disks, writes are mirrored).

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crookedview, do you use passthrough for you controller? or RDM for disks? or you a using traditional VMDK?

How you check your speed? via LAN? or console?

 

Do you have data on your SHR? Can you delet it and create RAID-0 to check speed?

In RAID-0 you must have 200Mb/s and more, if no than controller can be a bottleneck due bad drivers. Or if you using VMDK it can be problems with ESXi.

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Please keep in mind that your HDDs will or may have different R/W speeds compared to the 5TB disk in single mode (don't know how different your HDDs are).

 

AFAIK Synology's SHR doesn't use ZFS (or I missed something).

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Synology uses mdadm for RAID, even for SHR. So you can google mdadm RAID1 read perfomance.

 

I made some test. RAID1 do not impruve single-threaded read.

 

Disk2 and Disk9 is SHR

 

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You will see speed boost in RAID1 only if you will read two or more different files simultaneously.

799d78c5d9ce.png

 

use RAID10 to boost your single-threaded read.

f56a6ae0804f.png

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