ONTAP Discussions

Mixed SAS/SATA/SSD stack limits?

aborzenkov
3,156 Views

Could someone point me to a document that clear states mixed stack limits? I know that pure SSD stack is restricted to 4 shelves, but at least one document claims 6 shelves in mixed stack (it is internal document so I'm happy to discuss it offline if appropriate). HWU shows limits for SAS/SATA/SSD separately, but again is silent about mixed usage.

 

I would say HWU should explicitly describe limits in this case.

7 REPLIES 7

Veldmaat
3,097 Views

Hello and good day,

 

Indeed, SSD stack is restricted to 4.

SSD is in fact the highest restrictive factor in these mixtures.

Therefore, if no SSD is involved, another max value  is shown.

 

I will see if there is an exact document describing this.

 

Would you be willing the share the internal document link with me, so i can check that document for reference?

 

Thanking you in advance!

aborzenkov
3,084 Views

@Veldmaat wrote:

Indeed, SSD stack is restricted to 4.


This can also be interpreted as "no more than 4 SSD shelves in a mixed stack".

 



Would you be willing the share the internal document link with me, so i can check that document for reference?


Sure. 6Gb SAS-2 SE Presentation, pages 47 which explicitly gives different limit for mixed stacks.

shuklas
3,093 Views

https://track.netapp.com/Ticket.aspx?pid=2

Please pass this feedback using above link and HWU team will reach out to you .

aborzenkov
3,083 Views

@shuklas wrote:

Please pass this feedback using above link and HWU team will reach out to you .


HWU is unclear about mixed SAS/SSD or SATA/SSD stack limits

andris
3,029 Views

The Field Portal document is accurate - the hybrid stack limits were recently relaxed to maximum 6 shelves (formerly 4 shelves).  Thank you for opening the HWU ticket.

AlexeyF
932 Views

Is there any performance penalty for the SSD Shelf if it's on the same stack as SATA(NL-SAS) shelf?

andris
918 Views

To avoid performance impacts for the SSDs, place the SSD shelves on the ends of the (MP-HA) stack. That minimizes the number of shelf hops to the SSDs from the controllers.

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