Which model are you trying to configure. It sounds like a bug in CxP but it’s hard to tell. EFDs are only available in 3.5” at GA so you will need a 15x3.5” DAE for FASTCache regardless.
I see the same thing in DirectExpress. I found no notes in the VNX FAQs about this restriction so I expect that it is probably a configurator issue. If you are planning to use FASTCache it probably makes sense to use the 3.5” DPE. The 2.5” DPE is the same size in the rack and you’d need 3.5” DAEs anyway. 2.5” and 3.5” drives can hot spare for each other as well.
Thanks for your respons Richard, but...still it feels like we just speculate if it´s a configuration issue in DX/CX or if it is some real limitation having the first DPE as 2.5" x 25 disks even if we add a second 3.5" DAE regarding adding Fast Cache.
Hope someone can give me the facts about this topic.
I wouldn't be to happy to order a couple of flash disks and licenses my customers could't use anyway.
I confirmed with Engineering that it is not possible to configure FASTCache with a 2.5" DPE today. This will be changed in the mid-March update of DX/CX.
I would like to bring this topic back to life. I see that the VNX Capacity Calculator 3.5.1 allows you to add 2.5" drives as FAST Cache and so does ChannelXpress. Was this a cx/dx config issue or a OE issue that was fixed?
My understanding was that there was a DXP issue early on, but availability of 2.5” FASTCache configs was fixed a while ago I believe. There is a new DXP rule though that enforces the FASTCache drives to be the same formfactor as the vault drives. If Vault disks are 3.5”, only 3.5” FASTCache drives will be available, and vise-versa.
Storagesavvy
474 Posts
0
February 23rd, 2011 15:00
Which model are you trying to configure. It sounds like a bug in CxP but it’s hard to tell. EFDs are only available in 3.5” at GA so you will need a 15x3.5” DAE for FASTCache regardless.
Storagesavvy
474 Posts
0
February 23rd, 2011 16:00
Hmm,
I see the same thing in DirectExpress. I found no notes in the VNX FAQs about this restriction so I expect that it is probably a configurator issue. If you are planning to use FASTCache it probably makes sense to use the 3.5” DPE. The 2.5” DPE is the same size in the rack and you’d need 3.5” DAEs anyway. 2.5” and 3.5” drives can hot spare for each other as well.
johanvitsas
5 Posts
0
February 23rd, 2011 16:00
It's for all VNX models. Even if I add an 3,5" DAE after choosing 2,5" as DPE.
The only way to be able to add Fast Cache is choosing first DPE as 3,5".
Anyone?
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24 feb 2011 kl. 00:52 skrev "Richard Anderson" >:
EMC Community Network
Fast-Cache and 25 x 2.5" drive DPE not compatible?
reply from Richard Anderson in Unified Storage - View the full discussion
johanvitsas
5 Posts
0
February 24th, 2011 01:00
Thanks for your respons Richard, but...still it feels like we just speculate if it´s a configuration issue in DX/CX or if it is some real limitation having the first DPE as 2.5" x 25 disks even if we add a second 3.5" DAE regarding adding Fast Cache.
Hope someone can give me the facts about this topic.
I wouldn't be to happy to order a couple of flash disks and licenses my customers could't use anyway.
/Johan
Storagesavvy
474 Posts
0
February 24th, 2011 09:00
I’m talking to Engineering about this and will let you know what I find out, hopefully later today.
Storagesavvy
474 Posts
0
February 24th, 2011 10:00
I confirmed with Engineering that it is not possible to configure FASTCache with a 2.5" DPE today. This will be changed in the mid-March update of DX/CX.
johanvitsas
5 Posts
0
February 24th, 2011 23:00
Thanx for raelly digging in this question Richard!
It would be nice if you could find out (from engineering) if it´s:
1, a physical limitation
2, a cxp/dxp configuration limitation
3, If it's a limitation and not just a cxp/dxp issue, what´s causing that limitation?
/Johan
jcingle1
16 Posts
0
March 29th, 2012 14:00
I would like to bring this topic back to life. I see that the VNX Capacity Calculator 3.5.1 allows you to add 2.5" drives as FAST Cache and so does ChannelXpress. Was this a cx/dx config issue or a OE issue that was fixed?
Storagesavvy
474 Posts
0
March 29th, 2012 14:00
My understanding was that there was a DXP issue early on, but availability of 2.5” FASTCache configs was fixed a while ago I believe. There is a new DXP rule though that enforces the FASTCache drives to be the same formfactor as the vault drives. If Vault disks are 3.5”, only 3.5” FASTCache drives will be available, and vise-versa.
Richard J Anderson