FAST & Pool LUN limitation size

Question

Hi to all, I have a CX4-480 with FAST and FC and SATA disks. I need a single LUN in my server with about 60TB capacity. But I faced the capacity limitation of 14TB to create a pool LUN.

Please help me how can I have a 60TB LUN with FAST enabled.

Message was edited by: Mohammad-t5tDw The 60TB is media files which we need to store more access data to FC and the other in SATA

dynamox · Accepted Answer

if you want to take advantage of FAST , i don't see any other option.

Storagesavvy · Answer

60TB is an enormous amount of data to be stored in a single LUN. Remember that a single LUN only has a single IO queue at the host level, so you could bottleneck and queue IOs at the host if there is a decent amount of concurrency in the workload.

Additionally, that LUN is going to be owned by only one SP, so all of the IO load will be handled by that SP while the second SP is going to sit idle.(assuming you don’t have other 60TB LUNs you are creating.)

What is the OS you are presenting the LUN to? What is the application and filesystem?

You may be able to create 4 LUNs and then join them together in the host. If you have multiple LUNs you can set the LUN ownership to evenly distribute across the SPs as well.

Richard J Anderson

dynamox · Answer

16TB is the maximum capacity virtual pool LUN, i am afraid you might have to utilize traditional raid groups and MetaLUNs (and of course no FAST). What is this 60TB for ?

dynamox · Answer

what operating system ?

M.Hani · Answer

The OS is CentOS 6.0 and the FS is OCFS2. I want to know waht is the usefull of FAST with this 14TB capacity limitation ?

dynamox · Answer

it's a LUN limit, not a pool limit. Multiple LUNs in a pool can take advantage of FAST. You could create multiple 16TB LUNs and put them in one volume group and take advantage of FAST ?

M.Hani · Answer

So you mean the only solution is to create multiple 14TB LUN and join them in host using LVM ?

CLARiiON

FAST & Pool LUN limitation size

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