# MinIO Storage Class Quickstart Guide [![Slack](https://slack.min.io/slack?type=svg)](https://slack.min.io)

MinIO server supports storage class in erasure coding mode. This allows configurable data and parity drives per object.

This page is intended as a summary of MinIO Erasure Coding. For a more complete explanation, see <https://min.io/docs/minio/linux/operations/concepts/erasure-coding.html>.

## Overview

const (
	// browserCSPPolicy setting name for Content-Security-Policy response header value
	browserCSPPolicy = "csp_policy"
	// browserHSTSSeconds setting name for Strict-Transport-Security response header, amount of seconds for 'max-age'
	browserHSTSSeconds = "hsts_seconds"
	// browserHSTSIncludeSubdomains setting name for Strict-Transport-Security response header 'includeSubDomains' flag (true or false)
	browserHSTSIncludeSubdomains = "hsts_include_subdomains"

	}

	if lc != "" {
		args["LocationConstraint"] = []string{lc}
	}

	cloneHeader := r.Header.Clone()
	if v := cloneHeader.Get("x-amz-signature-age"); v != "" {
		args["signatureAge"] = []string{v}
		cloneHeader.Del("x-amz-signature-age")
	}

	if userTags := cloneHeader.Get(xhttp.AmzObjectTagging); userTags != "" {
		tag, _ := tags.ParseObjectTags(userTags)
		if tag != nil {
			tagMap := tag.ToMap()

	processIOWCharBytesMD             = NewCounterMD(processIOWCharBytes, "Total bytes written by the process to the underlying storage system including page cache, /proc/[pid]/io wchar")
	processIOWriteBytesMD             = NewCounterMD(processIOWriteBytes, "Total bytes written by the process to the underlying storage system, /proc/[pid]/io write_bytes")

//
//
// On illumos an explicit O_DIRECT flag is not necessary for two primary
// reasons. Note that ZFS is effectively the default filesystem on illumos
// systems.
//
// One benefit of using DirectIO on Linux is that the page cache will not be
// polluted with single-access data. The ZFS read cache (ARC) is scan-resistant
// so there is no risk of polluting the entire cache with data accessed once.

			Optional:    true,
			Type:        "string",
		},
		config.HelpKV{
			Key:         browserHSTSSeconds,
			Description: `set Strict-Transport-Security 'max-age' amount of seconds value` + defaultHelpPostfix(browserHSTSSeconds),
			Optional:    true,
			Type:        "number",
		},
		config.HelpKV{
			Key:         browserHSTSIncludeSubdomains,

// row. They have an output for each input row.
//
// Some types of a queries are not valid. For example, an aggregation
// function combined with a row function is meaningless ("AVG(s.Age) +
// s.Salary"). Analysis determines if such a scenario exists so an
// error can be returned.

var (
	// Fatal error for query processing.
	errNestedAggregation      = errors.New("Cannot nest aggregations")