Deduplication CS500 with NOS 5.0.5.0

[Roland Kudelic]

Hi

After NOS Upgrade to 5.0.5.0 i have enabled dedup on each volume. Select volume with checkbox, click on more (...) there you can enable deduplication.

The FDR ist 9%, minimum 4% required.

I have enabled deduplication on all volumes yesterday evening. Today the space consumtion is the same as before.
Is there anything more, what I must do?

Regards
Roland

[Seenivasan-XP]

Hi Roland Kudelic,

Dedupication on Hybrid Arrays

NimbleOS 5.0.1.0 and 5.0.2.0 added support for deduplication on HPE Nimble Storage CS7000, CS5000, and CS3000 hybrid arrays.

These restrictions apply to deduplication on hybrid arrays:

• To use deduplication on a hybrid array, it must include six or more SSD drives.
• Pinned volumes cannot be deduplicated.
• Deduplication cannot be enabled at the pool level or across striped pools.
• Replicated data is not deduplicated; the data is replicated without any deduplication savings.

Before you enable deduplication on hybrid arrays, review the product documentation for complete details.

The following tables provide information about the Maximum Dedupe Capacity (MDC) on supported hybrid arrays and the additional Flash to Disk Ratio (FDR) required to support MDC.

Note: You must have a four percent FDR to enable dedupe on these hybrid models. For MDC, you must have an additional four percent FDR for a total of eight percent FDR. To see the dedupe capacity (TiB), log in to the NimbleOS CLI as an administrator and run the

pool --info pool_name

command.

Effective Capacity and Additional Flash Required to Support MDC Platform Maximum Dedupe Capacity (MDC) Effective Capacity with 3x Dedupe Additional Flash Required to Support MDC CS3000 40 TiB 120 TiB 1.6 TiB CS5000 100 TiB 300 TiB 4 TiB CS7000 200 TiB 600 TiB 8 TiB

[Seenivasan-XP]

Hi Roland Kudelic,

You can enable deduplication for CS3000, CS5000, CS7000, CS700, and CS500 arrays on a volume only if the corresponding storage pool has a Flash to Disk Ratio (FDR) of 4% or higher. To calculate the FDR, obtain the "Total array capacity (MiB)" and "Total array cache capacity (MiB)" values by using the HPE Nimble Storage CLI command pool -- info pool_name. This commandreturns the Poolcapacity(MiB), which is the "Total array capacity (MiB)", and the Pool cache capacity (MiB), which is the "Total array cache capacity (MIB)". Then perform the following calculation: FDR = "Total array cache capacity (MiB)"/"Total array capacity (MiB)" * 100 If the array has sufficient capability for deduplication, the pool --info command will also show a value for dedupe capacity (MiB). Note On the HF20H, HF20, HF40, and HF60 platforms, pool --info displays "N/A" as the value for dedupe capacity (MiB). This because you can enable deduplication for the entire array.

[Nick_Dyer]

What the above hasn't said, is that deduplication is only on _new data_ written to your volumes, as dedupe is inline, not post process.

You'll need to migrate your data to new dedupe enabled volumes in order to see any space saved.

BTW - you need an extra 4% Flash to Disk in your array for dedupe to work without any performance impact. If you don't do this, then the array will take 4% away from your 9% for dedupe, meaning application data caching may suffer.