ECS 3.6.2 Data Access Guide

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Cold Storage

Describes cold storage archives.

Cold archives store objects that do not change frequently and do not require the robust default EC scheme. The EC scheme used for a cold archive is 10 data fragments plus two coding fragments (10/12). The efficiency is 1.2x.

You can specify a cold archive (Cold Storage) when creating a new storage pool. After the storage pool is created, the EC scheme cannot be changed. This scheme can support the loss of a single node. It also supports loss of one drive out of six or two drives out of 12 on two separate nodes.

EC requirements

Table 1. Requirements for regular and cold archives comparedThe table shows the description for regular and cold archives comparison
Use case	How enabled	Minimum required nodes	Minimum required disks	Recommended disks	EC efficiency	EC scheme
Regular archive	Default	4	16*	32	1.33x	12/16
Cold archive	Configured by System Administrator	8	12*	24	1.2x	10/12

NOTE: *Since the minimum deployable configuration for the C-Series appliance is two appliances with 12 disks each, 24 disks is the effective minimum.

Storage pool configuration

To establish a cold archive from the portal, Select Cold Storage when you create a storage pool. Once a storage pool has been created, this setting cannot be changed.