AMASS Overview

Tape Streaming

Streaming tape IO provides a constant flow of data output to a

Improves Write

drive, which lessens start and stop operations. This feature

Performance

typically improves write performance but depends on file size,

 

number of files, and drive type.

 

During processing, a cache block has the following three states

 

described:

 

• Queued = Cache block of data waiting for IO to start

 

• Pending = Cache block of data in the drives’s buffer

 

• Done = Cache blocks that have been verified as written to

 

media

 

The following figure illustrates these three states:

QUEUEDPENDING

Drive

D

A

T

A

 

I

N

 

C

A

C

H

E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2. ... one block in the drive’s buffer is freed-up so data continues to be written to the drive.

DONE

1.As one block of data is written to media ...

Tape streaming is configured globally with the config_prod -oscript after you install AMASS. For more information about this script, refer to the Optional Parameters appendix in Installing AMASS.

Refer to the AMASS Release Notes for a list of valid drives for I/O tape streaming.

6-00026-01 Rev A

Online Archiving with AMASS

1-17