Simple, Scalable, Flash-Optimized and Amit Bothra Arvind Pruthi

12 Pages·2013·0.39 MB·English

by  Amit Bothra

SeFS
Simple, Scalable, Flash-Optimized and

Amit Bothra
Arvind Pruthi
Flash Memory Summit 2013
Santa Clara, CA 1
Efficiency at Every Level
§  Reads
§  Writes
§  Journaling
§  Block Allocation
§  Garbage Collection
§  Low Memory Overhead
§  Simple, yet scalable
Traditional File System Stack
NFS CIFS
VFS Layer
(Inode + Block Offset) (Lun + VBN)
Journal File System ->
Block Allocation Scheme
Block Layer
(Lun + VBN) (Device + LBA)
RAID Layer ->
LBA (Cyl + Track + Offset)
->
Traditional File System Stack w/
SSDs
NFS CIFS
Overhead
VFS Layer
(Inode + Block Offset) (Lun + VBN)
Journal File System ->
Block Allocation Scheme
Overhead
Block Layer
(Lun + VBN) (Device + LBA)
RAID Layer ->
Added Overhead -
(LBA) (PBA) Additional Map
->
GC & Block Allocation Scheme
Enterprise Log-Structured File
System Stack w/SSDs
NFS CIFS
(Inode + Block Offset) (Lun + VBN)
->
File System
Journal
Log structured layout overheads
Block Layer
(Lun + VBN) (Device + LBA)
RAID Layer ->
(LBA) (PBA)
->
GC + Block Allocation Scheme
Enter Skyhawk
Vertically
Integrated
File System
Stack
Benefits of SeFS
NFS CIFS
VFS Layer
Journal File System
Block
Allocation
Block Layer
RAID Layer
Benefits of SeFS
NFS CIFS
Journal File System
Block
Allocation
Block Layer
RAID Layer
Benefits of SeFS
NFS CIFS
Journal File System
Block
Allocation
RAID Layer
Benefits of SeFS
NFS CIFS
Journal File System
•  FTL with Global wear Levelling
•  Sparse VBN -> PBA Mapping
•  Block Allocation
•  GC