The following table provides the function specifications for the Deduplication/Compression.
Table 14
Deduplication/Compression Function Specifications
Model
ETERNUS AF250 S3
ETERNUS AF650 S3
Number of TPPs available for Deduplication/Compression settings
4
8
Maximum logical capacity that can be a deduplication/compression target
Up to ten times the DATA_CNTNR Volume (*1)
Maximum logical capacity of
the DATA_CNTNR Volume (*2)
If the chunk size is 21MB
384TB
1,536TB
If the chunk size is 336MB
6,144TB
24,576TB
Volume type
TPV
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Standard / FTV / WSV / SDV / SDPV / VVOL /
ODX
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*1:
If a Deduplication/Compression Volume is created or expanded, expand the DATA_CNTNR Volume according to the total capacity of
the Deduplication/Compression Volumes. If the efficiency of the Deduplication/Compression function cannot be estimated, the
recommended total capacity of Deduplication/Compression Volumes is a capacity smaller than the logical capacity of the
DATA_CNTNR Volume.
*2:
When the Deduplication/Compression function is used, the total capacity of the Deduplication/Compression Volumes can be greater
than or equal to the capacity of the DATA_CNTNR Volume. If deduplication/compression is not effective for this case, a write
operation to a Deduplication/Compression Volume may fail due to a capacity shortage of the DATA_CNTNR Volume. The default
logical capacity of the DATA_CNTNR Volume is 32TB.
In addition, if the DATA_CNTNR Volume capacity runs out or is close to running out, an SNMP Trap is sent.
●
Performance When Using the Deduplication/Compression Function
The ETERNUS AF performs data deduplication/compression in synchronization with the I/O from the server.
•
Using this function in environments where random access occurs is recommended. Data is intermittently
stored in Deduplication/Compression Volumes because data is appended.
•
I/O response may significantly degrade when compared to systems that do not use the Deduplication/
Compression function.
•
Using this function in environments where the I/O size is 32KB or smaller is recommended. The
performance is affected in environments where the I/O size is large because data is deduplicated and
compressed every 8KB.
•
If the I/O size or the boundaries of the I/O address are not 8KB, the performance is affected because the
parts less than 8KB are read in the ETERNUS AF.
•
If I/Os are issued to the Deduplication/Compression Volumes, the CPU usage rate increases. The
performance of non-Deduplication/Compression Volumes may also be affected.
•
The controller that controls the data reduction process of the Deduplication/Compression function is called
the data reduction CM. By replacing the data reduction CM assigned to the Deduplication/Compression
Volume, the memory and load of the CMs can be balanced during the data reduction process.
2. Basic Functions
Operations Optimization (Deduplication/Compression and Storage Virtualization)
44
Design Guide
Содержание ETERNUS AF S3 Series
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