The document discusses the anatomy of file systems and how they are organized on hard disks. It explains that file systems organize scattered data using indexes containing metadata and data blocks containing file contents. File system blocks are mapped to disk blocks using logical block addressing. File systems use inodes to store file and directory metadata, with each file or directory having a corresponding inode containing attributes like owner, size, and pointers to data blocks. Block groups contain groups of inodes and data blocks to organize the file system layout on disk.
A fast file system for unix presentation by parang saraf (cs5204 VT)Parang Saraf
This is the presentation of the paper "A fast file system for unix"
In case if you need a copy of these slides feel free to contact me at parang[DOT]saraf[AT]gmail
A fast file system for unix presentation by parang saraf (cs5204 VT)Parang Saraf
This is the presentation of the paper "A fast file system for unix"
In case if you need a copy of these slides feel free to contact me at parang[DOT]saraf[AT]gmail
A Security Barrier Device That Can Protect Critical Data Regardless of OS or ...CODE BLUE
A Security Barrier Device protects PC and other control devices by relaying every port between the motherboard and the peripherals. The SBD is totally transparent from the PC and can be installed regardless of OS or application. At this presentation I will discuss the storage securing function achieved by the SBD relaying the SATA port.
The SBD has a security information disk only accessible to itself where it stores the access privilege information of the original disk in the PC. When the PC issues a data access request to the original disk, the SBD will reference the access privileges of that particular sector, if the sector is read-deny then returns dummy data of 0 , if the sector is write-deny then it won’t write to that sector. The SBD not only allows for sector based protection but also a file based protection. In case of a file write-deny, there were some issues with the disc related cache in memory not being synchronised or the pointer’s position to the file in regards to its directory being shifted , but I will show how it was solved.
I will also talk about the fact that a SBD is an effective protection against any malware that attempts to manipulate the boot data sector or system files, once it detects any access right violations it can shutdown the ethernet port remotely and thwart the spreading of malware.
Kenji Toda
At the National Institute of Advanced Industrial Science and Technology conducted research and development of 30 Gbps intrusion detection systems , 60 Gbps URL filtering systems and or network devices testing equipment for such systems. Currently co-developing security barrier devices with the Research and Development Control System Security Center. (Presented at international conferences regarding MST and real-time systems)
http://codeblue.jp/en-speaker.html#KenjiToda
Ch 17 disk storage, basic files structure, and hashingZainab Almugbel
Modified version of Chapter 17 of the book Fundamentals_of_Database_Systems,_6th_Edition with review questions
as part of database management system course
A Security Barrier Device That Can Protect Critical Data Regardless of OS or ...CODE BLUE
A Security Barrier Device protects PC and other control devices by relaying every port between the motherboard and the peripherals. The SBD is totally transparent from the PC and can be installed regardless of OS or application. At this presentation I will discuss the storage securing function achieved by the SBD relaying the SATA port.
The SBD has a security information disk only accessible to itself where it stores the access privilege information of the original disk in the PC. When the PC issues a data access request to the original disk, the SBD will reference the access privileges of that particular sector, if the sector is read-deny then returns dummy data of 0 , if the sector is write-deny then it won’t write to that sector. The SBD not only allows for sector based protection but also a file based protection. In case of a file write-deny, there were some issues with the disc related cache in memory not being synchronised or the pointer’s position to the file in regards to its directory being shifted , but I will show how it was solved.
I will also talk about the fact that a SBD is an effective protection against any malware that attempts to manipulate the boot data sector or system files, once it detects any access right violations it can shutdown the ethernet port remotely and thwart the spreading of malware.
Kenji Toda
At the National Institute of Advanced Industrial Science and Technology conducted research and development of 30 Gbps intrusion detection systems , 60 Gbps URL filtering systems and or network devices testing equipment for such systems. Currently co-developing security barrier devices with the Research and Development Control System Security Center. (Presented at international conferences regarding MST and real-time systems)
http://codeblue.jp/en-speaker.html#KenjiToda
Ch 17 disk storage, basic files structure, and hashingZainab Almugbel
Modified version of Chapter 17 of the book Fundamentals_of_Database_Systems,_6th_Edition with review questions
as part of database management system course
2. Anatomy of Hardisks
Track 1 “Platter” – A circular piece of
magnetic material
“Tracks” – Platters divided into
concentric circles
Track 0
Read/Write Head 0
Platter1,track0
Read/Write data from Hardisk ? Platter2,track0 Cylinder 0
Read Cylinder
0,head 0, Platter3,track0
sector 0.
Disk Controller.
CHS Addressing
bennojoy@gmail.com Does operations like read, write etc..
4. Communicating with your Hardisk
Various communication standards exist to talk to our Harddisks:
Communication Requirements SCSI Specification
Speaker/Listener Initiator/Target
Voice/Language SCSI Commands
Medium SCSI Bus
Addressing SCSI ID
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5. SCSI Overview
Target Host Bus Adapter(HBA)
ID: 0 8 Bit wide wires
Target SCSI Bus Converts: PCI -Bus
PCI -> SCSI CPU
ID: 1 Initiator
Target
ID: 7
Logical Block Addressing (LBA) – A Data Addressing Standardization:
Block 0/1 Block 2/3
Track 0 Track 1
Sector 0 Sector 1 Sector 0 Sector 1
SCSI Command
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6. SCSI Communication in Action
OS: CPU: Give me Block 1, from disk0
OS: your
data, ”Hello” CPU HBA: Give me Block 1, From Disk 0
CPU: Your data “Hello”
Bus Adapter:
Initiator Hey, Disk 0, I Need your attention
Thanks, READ LBA 2 for me
Ok Bus, You have my attention
Converts LBA 2 –> CHS 0/0/1 Target Disk0
Ok, Here is LBA 2 Data: “Hello” ID 0
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9. FileSystems – Contd…
Block Groups:
Block Group 0
Super Group Descriptor Inode
Data Blocks … N
Block Blocks.. Blocks
Inodes :
Every file or Directory will have a corresponding Inode, which contains information
corresponding to the file or directory Entries in an Inode :
Inode Block: Owner
Inode 1 Mode (permission/Directory/File)
128 bytes
TimeStamp
Inode 2
Address of 1st Data Block
Inode … Address of 2nd Data Block
Inode 32 Address of Direct and Indirect Data Block
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10. FileSystems – Contd…
Difference between file and directory Inode:
File Inode : Data Block 22:
Owner
Hello
Mode (File)
World !
TimeStamp
Data Block 22
Address of 2nd Data Block
Address of Direct and Indirect Data Block
Directory Inode : Data Block 50:
Owner
Mode (Directory) “File1” - 32
TimeStamp “File2” - 36
Data Block 50
Address of 2nd Data Block
Address of Direct and Indirect Data Block
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11. FileSystems – Contd…
SuperBlock :
Free Blocks
Free Inodes
Size
Block Size etc..
Group Descriptor :
Block Number of First Inode
No of free blocks in group
Revisit the FileSystem Layout in Disk:
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12. FileSystem in Action
Listing Contents of a file:
• Read the inode entry of / (Root
directory)
• The root inode is fixed, inode entry 2
in the first inode block of the first
blockgroup
Test Inode
Mode (Directory) “a” – Inode(5)
Data Block 2
Root Inode
Mode (Directory) A Inode “Test” – Inode(3) “hello world”
Mode (File)
“Bin” – Inode(4)
Data Block 1
Data Block 3
Inode1 Inode2 Inode3 Inode4 Inode5 Block1 Block2 Block3 Block4 Block5
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