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How is device moving in FAST and FAST VP?
In FAST DP, move and swap takes place. If move, then target tier should have unconfigured space to make the move. Is it std device relocating from one tier to another or only data is moving from one tier to another as move creates hyper on unconfigured space in target tier.
While in swap, it is clear that device is relocating from one tier to another which means that RAID, technology and physical location of the device is also changing.
In FAST VP, it is clear that device movement is happening with movement of extents across the tiers. Tiers are made of Thin pools with data devices created from different disk groups of different technology. Is the physical location of the extents being moved and is technology also changing in this case.
Your advise will be highly appreciated.
BR
RK
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seancummins
226 Posts
1
September 25th, 2013 06:00
RK -- yes, the physical location of extents changes when FASTVP performs promotions and demotions of said extents. The underlying drive & RAID technology supporting those extents also changes as a result of the movement activity. You end up with TDEVs (LUNs) that have extents distributed across multiple tiers, so a given TDEV will have multiple underlying drive & RAID technology types.
Thanks,
- Sean
SYMCLIGuy
98 Posts
1
September 25th, 2013 07:00
The way in which data is moved by FAST DP is covered in this document
https://support.emc.com/docu9286_Implementing_Fully_Automated_Storage_Tiering_(FAST)_for_EMC_Symmetrix_VMAX_Series_Arrays_Technical_Note.pdf?language=en_US
While the way data is moved by FAST VP is covered in this document
https://support.emc.com/docu31003_FAST_VP_for_Symmetrix_VMAX_Theory_and_Best_Practices_for_Planning_and_Performance.pdf?language=en_US
RK_Storage
3 Posts
0
September 25th, 2013 09:00
Thank Sean,
I got it.
So in case of FAST DP, complete device will move or swap from one tier to another [source to target tier].
In case of FAST VP, extents will move from one tier to another.
Thanks,
RK
RK_Storage
3 Posts
0
September 25th, 2013 09:00
Thanks!
White paper is good.
Regards
Ram