NL SAS for Vault drives (VNX)

It's always been suggested to not run demanding workloads on any LUN created on a Vault drive RAID Group, even when they are 15k SAS.

The context being that doing so may impact performance. When you consider the performance capability of NL-SAS, I wouldn't be doing it. In fact I generally try and make a point of excluding any available user space on Vault drives into the overall capacity figure of an array.

I'm not aware of any official documentation or guidance on this though.

Thanks for your response - I am not looking to use the vault drives for any data other then the OE. I am coming from the thought that if you have a system that handles many operations, will the OE on a NL SAS disks have any performance issues? 

I have seen VNX5300 installs with NL-SAS drives being used for OE, so it’s supported ..at least for that model.

Thanks dynamox - that is correct they are supported for all VNX models but are they any gotchas - as in things to watch out for etc

jrai wrote: Thanks dynamox - that is correct they are supported for all VNX models but are they any gotchas - as in things to watch out for etc

With no userdata loads I wouldn't expect any performance impact.

I don't think your info is correct. For VNX1, only the 5100, 5300 and 5500 support NL-SAS as vault drives, and for VNX2 only the 1TB drives are supported. Check the respective Storage Systems Disk and OE Matrix.

If you're not going to use the space, why are you considering the higher capacity drives....cost ?

https://support.emc.com/docu31714_VNX5100-and-VNX5300-Storage-Systems-Disk-and-OE-Matrix.pdf?language=en_US

https://support.emc.com/docu31715_VNX5500,-VNX5700-and-VNX7500-Storage-Systems-Disk-and-OE-Matrix.pdf?language=en_US

https://support.emc.com/docu48859_VNX5200,-VNX5400,-VNX5600-VNX5800,-VNX7600-and-VNX8000-Storage-Systems-Disk-and-OE-Mat…

That's cool.

..and Dynamox is on the money. When a Vault drive dies, you'll be thankful for shorter rebuild times

i have not seen anything in terms of documentation/discussion that would suggest when to use or not to use NL-SAS for OE. On a Unified box your datamover LUNs will reside on those drives but it's not like you are rebooting your datamovers on daily bases or they are swapping like crazy. I personally prefer to get the smallest SAS drives possible for OE,  fast rebuilds, smaller window of exposure.

Hi Bret,

Thanks for the information. Reason I ask is just curiosity

That is a good point - thanks for that

Once last thing to consider is when you get a lot of Pool LUNs on the array and there is a lot of activity occurring the vault drives can get pretty busy - I've seen cases where the NL-SAS used for Vault can start to have an impact on performance.

glen