3.1 KiB
Minio Storage Class Quickstart Guide
Minio server supports storage class in erasure coding mode. This allows configurable data and parity disks per object.
Overview
Minio supports two storage classes, Reduced Redundancy class and Standard class. These classes can be defined using environment variables
set before starting Minio server. After the data and parity disks for each storage class are defined using environment variables,
you can set the storage class of an object via request metadata field x-amz-storage-class
. Minio server then honors the storage class by
saving the object in specific number of data and parity disks.
Values for standard storage class (STANDARD)
STANDARD
storage class implies more parity than REDUCED_REDUNDANCY
class. So, STANDARD
parity disks should be
- Greater than or equal to 2, if
REDUCED_REDUNDANCY
parity is not set. - Greater than
REDUCED_REDUNDANCY
parity, if it is set.
Parity blocks can not be higher than data blocks, so STANDARD
storage class parity can not be higher than N/2. (N being total number of disks)
Default value for STANDARD
storage class is N/2
(N is the total number of drives).
Reduced redundancy storage class (REDUCED_REDUNDANCY)
REDUCED_REDUNDANCY
implies lesser parity than STANDARD
class. So,REDUCED_REDUNDANCY
parity disks should be
- Less than N/2, if
STANDARD
parity is not set. - Less than
STANDARD
Parity, if it is set.
As parity below 2 is not recommended, REDUCED_REDUNDANCY
storage class is not supported for 4 disks erasure coding setup.
Default value for REDUCED_REDUNDANCY
storage class is 2
.
Get started with Storage Class
Set storage class
The format to set storage class environment variables is as follows
MINIO_STORAGE_CLASS_STANDARD=EC:parity
MINIO_STORAGE_CLASS_RRS=EC:parity
For example, set MINIO_STORAGE_CLASS_RRS
parity 2 and MINIO_STORAGE_CLASS_STANDARD
parity 3
export MINIO_STORAGE_CLASS_STANDARD=EC:3
export MINIO_STORAGE_CLASS_RRS=EC:2
If storage class is not defined before starting Minio server, and subsequent PutObject metadata field has x-amz-storage-class
present
with values REDUCED_REDUNDANCY
or STANDARD
, Minio server uses default parity values.
Set metadata
In below example minio-go
is used to set the storage class to REDUCED_REDUNDANCY
. This means this object will be split across 6 data disks and 2 parity disks (as per the storage class set in previous step).
s3Client, err := minio.New("localhost:9000", "YOUR-ACCESSKEYID", "YOUR-SECRETACCESSKEY", true)
if err != nil {
log.Fatalln(err)
}
object, err := os.Open("my-testfile")
if err != nil {
log.Fatalln(err)
}
defer object.Close()
objectStat, err := object.Stat()
if err != nil {
log.Fatalln(err)
}
n, err := s3Client.PutObject("my-bucketname", "my-objectname", object, objectStat.Size(), minio.PutObjectOptions{ContentType: "application/octet-stream", StorageClass: "REDUCED_REDUNDANCY"})
if err != nil {
log.Fatalln(err)
}
log.Println("Uploaded", "my-objectname", " of size: ", n, "Successfully.")