What are three volume-level storage efficiency features of ONTAP? (Choose three.)
A.
deswizzle
B.
space reclamation
C.
compaction
D.
compression
E.
deduplication
Explanation:
DE: NetApp deduplication is an integral part of the NetApp Data ONTAP operating environment and the WAFL
file system, which manages all data on NetApp storage systems.
NetApp data compression, introduced in Data ONTAP 8.0.1, is highly complementary to deduplication.
A: Data within a FlexVol has both a logical location within the volume and a physical location within the
containing aggregate. When reading data from a FlexVol, the physical location of that data must be known to
perform the read. Under normal circumstances, reads use a fast-path to translate a logical address into a
physical address. When SnapMirror transfers a FlexVol to a different aggregate, however, the relationship
between logical and physical addresses is changed. The destination aggregate lays out the volume into
different physical blocks. Immediately after the SnapMirror transfer, reads to the destination volume will use a
different process to translate logical addresses into physical addresses. This slow-path is less efficient and may
require an additional disk read to access a block of data. As soon as a FlexVol SnapMirror update finishes, the
destination storage controller will launch a scanner to recreate the fast-path metadata. Once the scan finishes,
reads to the SnapMirror destination will use the normal fast-path. This process is known as deswizzling.http://community.netapp.com/t5/Tech-OnTap-Articles/Back-to-Basics-Deduplication/ta-p/84888
https://kb.netapp.com/support/s/article/ka21A0000000arxQAA/what-is-deswizzler-or-deswizzling?
language=en_US
For me it is not A. For me it must be CDE
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Compaction is an aggregate-level efficiency.
pg 18
http://www.netapp.com/us/media/tr-4476.pdf
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Hello
I’m agree with you
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Correct Answer is CDE, below is the exact reference for the three.
http://docs.netapp.com/ontap-9/index.jsp?topic=%2Fcom.netapp.doc.dot-cm-vsmg%2FGUID-9C88C1A6-990A-4826-83F8-0C8EAD6C3613.html
http://docs.netapp.com/ontap-9/index.jsp?topic=%2Fcom.netapp.doc.dot-cm-vsmg%2FGUID-9C88C1A6-990A-4826-83F8-0C8EAD6C3613.html
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Compaction is for AFF volume.
Deswizzling is more generic.
https://kb.netapp.com/support/s/article/ka21A0000000arxQAA/what-is-deswizzler-or-deswizzling?language=en_US
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I’ve never heard of deswizzle as a volume based storage efficiency! dewizzle is a low-pri back ground task used to move data around for shortest path… i.e. snapmirror from FC disk to SATA disk, deswizzle will rearrange blocks on the destination disk based to accommodate the different disk technology. It’s not like you can just deswizzle a volume at will (like a Windows defrag)… not without replicating it.
/snip
Enabling inline data compaction for FAS systems
You can control inline data compaction on FAS systems with Flash Pool (hybrid) aggregates or HDD aggregates at the volume or aggregate level by using the wafl compaction enable node shell command. Data compaction is disabled by default for FAS systems.
this snippet shows it’s at the VOL and AGGR level.
I would go with CDE
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I’d like to add that deswizzle isn’t taught as a storage efficiency feature and to be honest I thought it was a fake answer ’cause I’ve never heard of it before.
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