Poor Write Performance using Dell R540 with H330 ESXi 6.5

Question

On a new install of ESXi 6.5 on a new PowerEdge R540 using an H330 HBA, sustained write speeds to an SSD volume in RAID 1 and a SATA volume in RAID 5 are approximately 20 MB/sec. Symptoms are very similar to those described in this post: https://anthonyspiteri.net/esxi-6-5-storage-performance-issues-fix/. Unfortunately, the only driver available is a native lsi_mr3. After disabling that driver using the ESXi shell, the volumes connected to the H330 are no longer shown. I tried re-enabling the driver, but each time I reboot the driver is disabled, so the volumes are lost. But that is a problem for another day. The big question is:

What other options are available to improve performance under ESXi 6.5 to SSD and SATA volumes connected via the H330?

Is there a vmklinux driver that could be substituted in place of the native driver?

Daniel My · Accepted Answer

Hello

Based on your description, it does not sound like you are using an H330 HBA. If you have RAID 1 and RAID 5 virtual disks created on the H330 then it is the H330 RAID controller. We have an article about performance expectations on controllers without cache, especially when using parity. 20MB/s sustained writes with RAID 5, SATA spindle drives, and a controller without cache does not sound abnormal to me. The performance impact of the RAID 5 will be felt on the RAID 1 with SSDs because the controller has to pause all I/O to perform parity calculations once the queue is full.

https://www.dell.com/support/article/sln164091/

If you go to the R540 support page and select ESXi 6.5 in the OS drop-down there is a category called Enterprise Solutions. That has the custom images we provide. The important information section lists all of the VIBs that we change in the image. The VIB listed there is the one validated for the PERC in that OS version.

http://www.dell.com/support/

Thanks

mjtEF · Answer

Thank you for your response and for correctly identifying our case as using an H330 RAID controller.  If there was no ongoing disk activity on the RAID 5 array, would it still be expected that the RAID 1 SSD array would be limited to 20 MB/sec?

Daniel My · Answer

No, I would not expect two SSDs in RAID 1 to operate at 20MB/s, even under sustained writes.

Aside from checking to make sure you are using one of the drivers we have validated, you can also check to see if disk cache is enabled. I can't recall the default behavior on the H330, but if disk caching is disabled then enabling it could boost performance. Enabling disk cache could cause data corruption in the event of sudden power loss or hardware failure.

You may need to use a management program like OpenManage Server Administrator to enable disk caching. You can boot to our Support Live Image if you don't want to install OMSA in VMware.

https://www.dell.com/support/contents/article/product-support/self-support-knowledgebase/enterprise-resource-center/enterprise-tools/support-live-image

http://www.dell.com/storagecontrollermanuals/

mjtEF · Answer

Can you provide me the part number we need to purchase to replace the H330 in our servers with the H730P?

Daniel My · Answer

It looks like these are both available on dell.com, so you can enter the part number into the keyword search on our main site to get the sales page.

H730P - 405-AAMY, 5 digit part number J14DC
H740P - 405-AAMX, 5 digit part number DPNHJ

That is the kit part number. The kit contains the controller, mounting brackets, and some technical documentation. The 5 digit part number is what is typically used on the resale market. It is the part for just the controller.

mjtEF · Answer

With these part numbers, would we install them where the H330 is currently installed; that is, pull out the H330 and install the H730P in the same slot?

Daniel My · Answer

Yes, same slot and all of the cabling should be the same between an H330 and H730. It should be a fairly easy swap. The virtual disks should migrate as well. You can verify virtual disk migration in the H730 manual.

http://www.dell.com/storagecontrollermanuals/

mjtEF · Answer

I purchased brand new 405-AAOE (2) from Server Supply, since when I configured these servers originally at Dell.com, I did two versions, one with the H330 and the other with the H730P.  The part number shown in the details for the H730P was 405-AAOE.  However, now that they have arrived I've found that they do not fit in the case.  The SAS connector is closer to the edge such that it is pushing up against fan #4.  Does 405-AAOE have a different layout from 405-AAMY; that is, does 405-AAMY have the SAS connector in the same relative location as on the H330?

mjtEF · Answer

Alternatively, it appears that the PERC H730P could be installed vertically into the slot where the PERC riser connects, if the plastic piece that holds the plunger in place could be removed.  Is that possible?

Daniel My · Answer

The kit number I provided and the one you purchased both contain controller part number J14DC. The difference between the kits is the metal bracket that fastens them to the case. The kit you purchased is not listed for an R540, so the bracket in the kit will not likely to fit properly. You can try removing that bracket. The controller will not be secured in the system, but it may allow it to fit.

mjtEF · Answer

Thank you for your expert assistance throughout this inquiry.  Last question:  do 405-AAMY and J14DC include the cache battery and the cage to secure the battery to the controller card?

Daniel My · Answer

Yes, the battery should come preinstalled onto the controller.

PowerEdge Hardware General

Poor Write Performance using Dell R540 with H330 ESXi 6.5

Was this post helpful?