Altecice

Low I/O performance with ESXi 6.0

151 posts in this topic

I disagree about the vibration compensation in Red drives. WD specifically say that Red drives incorporate dynamic vibration dampening. I watched a video about it where it showed active counter balancers in the drives. I don't recall where I saw the video, but I'll see if I can find a link.

As far as I know, the WD Reds are just a tweaked WD Green with better tolerances + firmware.

 

"3D Active Balance Plus – We’ve tightened specifications on our exclusive dual plane balance technology to further minimize emitted vibration, lower noise, improve the hard drive performance and reduce the potential for errors during read/write operations"

 

The RE drives however have active dampening tech and the spindle is attached at both ends to also reduce vibration.

 

"RAFF - Enhanced RAFF technology includes sophisticated electronics to monitor the drive and correct both linear and rotational vibration in real time. The result is a significant performance improvement in high vibration environments over the previous generation of drives."

 

"StableTrac - The motor shaft is secured at both ends to reduce system-induced vibration and stabilize platters for accurate tracking during read and write "

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The video I saw showed ball bearing counter weights that moved to compensate for vibration. Haven't found a link to it yet.

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WD Red drives aren't that much faster.

A 2TB WD Green drive has a sustained internal transfer rate of 147MB/s

http://www.wdc.com/wdproducts/library/SpecSheet/ENG/2879-800026.pdf

Toshiba MK5076GSX has an internal transfer rate range of 73MB/s to 149MB/s. I would guess its sustained internal transfer rate would be around 73MB/s.

http://wfcache.advantech.com/www/certified-peripherals/documents/96nd640g-st-to5k_Datasheet.pdf

 

So in streaming of big files I would say the WD Red or Green drives could be twice as fast.

 

 

Laptop drive - Toshiba MK5076GSX 500gb

Other Desktop Drive - Seagate ST3500418AS 500GB  (the one that can just keep 1gbit speeed for the Iso)

The Seagate has a sustained transfer rate of 125MB/s

http://www.seagate.com/staticfiles/support/disc/manuals/desktop/Barracuda%207200.12/100529369b.pdf

 

For big file copies, transfer rate is more important than RPM.

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A 2TB WD Green drive has a sustained internal transfer rate of 147MB/s

http://www.wdc.com/wdproducts/library/SpecSheet/ENG/2879-800026.pdf

Toshiba MK5076GSX has an internal transfer rate range of 73MB/s to 149MB/s. I would guess its sustained internal transfer rate would be around 73MB/s.

http://wfcache.advantech.com/www/certified-peripherals/documents/96nd640g-st-to5k_Datasheet.pdf

 

So in streaming of big files I would say the WD Red or Green drives could be twice as fast.

 

 

The Seagate has a sustained transfer rate of 125MB/s

http://www.seagate.com/staticfiles/support/disc/manuals/desktop/Barracuda%207200.12/100529369b.pdf

 

For big file copies, transfer rate is more important than RPM.

 

Thanks for the info! :)

 

Its strange then, I still don't see why my transfers are sent to RAM first and then wrote to disk if the disk can sustain the write speed. Thats whats slowing everything down, as soon as it hits its magical 'cap' of 1.6gb modified RAM my transfer speed slows to 3-15mb/s from 110mb/s... the mystery continues :(

 

I have tried various suggested fixes for it all with no changes, I wonder if there is a way to stop things being written to RAM first and just write stright to the disk.... Then again Im not sure if thats ESXi causing the guest OS to do that.

Edited by Altecice

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I'm not sure how stopping data being written to RAM would help. Normally, RAM buffers are used to help speed up data transfers.

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I'm not sure how stopping data being written to RAM would help. Normally, RAM buffers are used to help speed up data transfers.

 

It was just a suggestion as it seems to be once the Modified limit is reached my transfer speed drops like a stone.

 

I would assume this has been fixed in 2012, but have you looked at this issue at all?

http://support.microsoft.com/en-us/kb/976618/en-us

 

I have just tested that and my Metafile is within normal limits. Its my Mapped File (specifically modified RAM column) that confirms my issue.

 

Could it be a older firmware/driver causing the issue?

I have taken a picture of my current firmware here :

 

 http://i.imgur.com/Dwqan6M.png.

 

Except from running firmware update via intelligent provisioning (and im not 100% confident it done what I asked):

 

(picture inc)

 

then setting the system to use ACHI mode and not the inbuilt raid controller. Activating write caching and the back USB's both via the bios, that's all I have done to the system before using ESXi. Should I be upgrading/ changing anything else?

Edited by Altecice

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Ohh I cant edit the above post anymore so here is a picture of the firmware upgade page I was going to post above: 

 

http://i.imgur.com/9CczmUQ.png

 

As you can see the installed version of the Network is 1.34 but the latest is 2.13.5, I have tried 3 times to let it upgrade and it succeeds with a code 1, Then it tried to re scan again for more updates but cant connect and so I reset my server and its still at 1.34.

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