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January 13th, 2022 00:00
5 x R740 Nodes for vSAN with HBA330 and ALL-FLASH SSD - Terrible Performance
Hello, I am experiencing performance issues with our vSAN infrastructure
I own 5 DELL R740 nodes with DELL HBA330 controller
All machines have 256GB of RAM
Each host has 1 x Samsung PM883 480GB SATA SSD cache disk
and 4 x Samsung PM883 SATA 1.92 for tier capacity
All machines have DELL 7.0u2 custom ISO with lsi-msgpt3 17.00.10.00-2vmw.702.0.0.17867351 driver controller
The controller mounts the firmware 16.17.01.00 (latest available)
I configured the datastore policies in FTT1 - RAID 5 (Erasure Coding)
All vSAN compatibility checks are green and there are no errors in the cluster.
The Number of disk stripes per object is set to 1 (but I also tried other values)
I also tried disabling the checksum object
I get TERRIBLE performances, on the single VM the Randon write capacity does not exceed 250 MByte / sec
The sequential reading is about 280 MByte / sec
I tried to change the policies and put FTT1 - RAID 1 but the performances do not differ much ..
I come from a previous configuration (same servers, same network cards and hard disk) with Qnap NAS and I got about 1080 MByte / sec in writing and as many in reading ..
What can it depend on? I state that it is not a network problem, with iperf between the hosts I can saturate the 10 Gigabit connection without problems
If I put the test VM in FTT0 in order to exclude the network from the equation, the writing speed improves a bit and goes to 330 Mbyte / sec
The test with HCI shows a throughput of 70 Megabytes / sec and 14k Iops
DiegoLopez
6 Operator
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2.7K Posts
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January 13th, 2022 07:00
Hello @Connectlife,
It's difficult for us to get involved in performance issues because normally this require an in deep log and configuration study that normally is out of the Support scope. You can try, however to contact with Dell Support if the server is in warranty and ask to speak with VSAN department. They might confirm if the configuration is correct.
One thing in your message that does not sound ok to me is that you are using Samsung PM883 disks that, as far as I know they are not enterprise compatible disks. There is not a dell firmware available for this disks.
Regards.
Connectlife
11 Posts
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January 13th, 2022 09:00
Hi all updated, idrac bios and HBA to the same versions.
I update you, I did some tests by directly installing the operating system and the results are as follows:
FIO results - 4k RandWrite: 53056 IOPS (212227 KB / s) - 4k RandRead: 81593 IOPS (326374 KB / s)
I cannot understand why the HBA330 does not reach the maximum speed of the SATA protocol
If I put the disks on a normal consumer PC I get to read at 550 Megabytes and write at c.a 450, which is the maximum limit of the SSD
DELL-Chris H
7 Practitioner
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9.7K Posts
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January 13th, 2022 09:00
ConnectLife,
I would verify that the systems themselves are also all up to date on BIOS, iDrac, and also the HBAs themselves.
Connectlife
11 Posts
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January 13th, 2022 09:00
Hi, yes the server is under warranty .. I also tested with the DELL SSD 480GB Hard Disks supplied with the server and the performances are identical (they mount DELL FW)