Introduction means of computer data storage Block storage File storage Object storage API used for storing computer data Introduction means of computer data storage Block storage 0 block 1 block ID: 913842
Download Presentation The PPT/PDF document "CEPH Introduction: means of computer dat..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
CEPH
Introduction: means of computer data storage
Slide2Introduction: means of computer data storage
Block storage
File storage
Object storage
API used for storing computer data
Slide3Introduction: means of computer data storage
Block storage:
0. block
1. block
2. block
3. block
4. block
5. block
Block read/write
Blocksize
(
eg
.
512b, 4KB)
Examples:
Most of physical data storage devicesHDD, SSD, pendriveSCSI, SATA, usb mass storage protocols are all block basedLBA scheme nowadays instead of a CHSLogical block devices made out of physical data storage devicesHardware/software RAID (pl. Linux md devices)Linux device mapper (/dev/dm-* devices)LVMEncrypted disks (dm-crypt)Also zvol (block device made out of a ZFS dataset)
Examples:
Variants of physical
data storage
device protocols that work over
IP/Ethernet
eg
.
iSCSI
Block API protocols of distributed data storage solutions
CEPH
RBD (RADOS block device)
Slide4Introduction: means of computer data storage
File storage:
Fájl
open, close, write, read, create, delete
Examples:
Filesystems
B
lock
, file, object storage
are often built on each other
Basic filesystems are based on blockBut in case of ZFS an object layer is placed between the file and block layer:
block -> object -> fileZFS zvol:
Block -> object -> blockExt4, xfs,
ntfs, fat, zfs, btrfs
IP based file access
SMB, NFS, WebDAVFile API of distributed data storage solutionscephFS, glusterfs
A lot of layers until we reach the block layer
Slide5Introduction: means of computer data storage
Object storage:
Unstructured data
In general object name is only a UUID
Flat namespace
Metadata
is key
To be able to search in the data
Metadata is indexed, object storage is optimized for searching based on metadata
Eg
. Searching pictures based on various properties
Background=blue, isThereAHuman=true, creationYear=2021 stb.
Example:AWS S3 API, OpenStack swift
There are API-s, lots of implementations
S3-at is also provided by Amazon as a serviceMost cloud storage solutions also use this in the
backgroudGoogle Drive (format of share links)Object API of distributed data storage solutions
CEPH librados, RGW (S3/swift)ZFS uses it internally, but it’s not accessible directly
Slide6CEPH
CEPH
Slide7CEPH
Distributed
data storage
solution
Free/open
source
Runs on “normal”
PC/server
machines
Open source alternative of vendor made, turnkey solutions4 API types
Object: LibradosObject: RGW
Block: RBDFile: CEPH FS
Slide8CEPH
Physical view
Daemons:
OSD.0
OSD.1
OSD.2
OSD.3
MON
MGR
OSD.4
OSD.5
MGR
MON
MGR
host1
host2
host3
CLIENT
CLIENT
Slide9CEPH
Logical view
Every daemon talks with each other
Those on the same host on loopback
Host boundaries have no role besides
optimalisation
Daemons:
OSD.0
OSD.1
OSD.2
OSD.3
MON
MGR
OSD.4
OSD.5
MGR
MONMGRCEPH clusterDaemon typesMON: monitorCentral configMGR: manager
OSD: object storage daemon
1
disk+cache
– 1 OSD
CLIENT: CEPH
client
Administration, data storage
CLIENT
CLIENT
Slide10CEPH
Every daemon talks with each other
No central node
The monitor only provides cluster information
Data storage
– RADOS object:
OSD.0
OSD.1
OSD.2
OSD.3
MON
MGR
OSD.4
OSD.5
MGR
MON
MGRCEPH clusterCLIENTCLIENT
Slide11CEPH
Replication
Erasure coding
Redundancy:
OSD.0
OSD.1
OSD.2
OSD.3
MON
MGR
OSD.4
OSD.5
MGR
MON
MGR
CEPH cluster
CLIENTCLIENT
Original
object
EC
blocks
Slide12CEPH
OSD.0
OSD.1
OSD.2
OSD.3
MON
MGR
OSD.4
OSD.5
MGR
MON
MGR
CEPH cluster
CLIENT
CLIENT
RBD:
Image file striped into multiple object client-side
RGW:
S3/swift object striped into multiple objects by RGW daemons
Slide13CEPH
OSD.0
OSD.1
OSD.2
OSD.3
MON
MGR
OSD.4
OSD.5
MGR
MON
MGR
CEPH cluster
iSCSI GW
iSCSI GW
iSCSI GW:
CEPH client
iSCSI target
iSCSI
initator
iSCSI
iSCSI