This document discusses RAID (Redundant Array of Independent Disks) storage systems and LVM (Logical Volume Management). It describes various RAID types including RAID 0, 1, 3 and 5 and how they provide features like performance, fault tolerance and redundancy. It also explains how LVM allows combining multiple physical disks into larger logical volumes for flexibility in resizing file systems with reduced downtime. Key components of LVM like physical volumes, volume groups and logical volumes are defined.
Kernel Recipes 2015 - Hardened kernels for everyoneAnne Nicolas
Grsecurity is a Linux kernel hardening patch. The PaX patchset it includes pioneered some security features like ASLR which where later included in basically every operating system. But the patch itself is still standalone (not included mainline), so most Linux users don’t benefit its security features.
A lot of people only use binary distribution kernels, and this talk will present some challenges found when trying to provide a distribution kernel with Grsecurity included.
I’ll first quickly present the grsecurity patch, then the attempt to include it in the Debian distribution kernel as a featureset. Finally there will be some pointers on how to provide hardened kernels easily for as many people as possible.
Yves-Alexis Perez, ANSSI
Let's trace Linux Lernel with KGDB @ COSCUP 2021Jian-Hong Pan
https://coscup.org/2021/en/session/39M73K
https://www.youtube.com/watch?v=L_Gyvdl_d_k
Engineers have plenty of debug tools for user space programs development, code tracing, debugging and analyzing. Except “printk”, do we have any other debug tools for Linux kernel development? The “KGDB” mentioned in Linux kernel document provides another possibility.
Will share how to experiment with the KGDB in a virtual machine. And, use GDB + OpenOCD + JTAG + Raspberry Pi in the real environment as the demo in this talk.
開發 user space 軟體時,工程師們有方便的 debug 工具進行查找、分析、除錯。但在 Linux kernel 的開發,除了 printk 外,還可以有哪些工具可以使用呢?從 Linux kernel document 可以看到 KGDB 相關的資訊,提供了在 kernel 除錯時的另一個可能性。
本次將分享,從建立最簡單環境的虛擬機機開始,到實際使用 GDB + OpenOCD + JTAG + Raspberry Pi 當作展示範例。
Systemd: the modern Linux init system you will learn to loveAlison Chaiken
The talk combines a design overview of systemd with some tutorial incofrmation about how to configure it. Systemd's features and pitfalls are illustrated by short demos and real-life examples. Files used in the demos are listed under "Presentations" at http://she-devel.com/
Video of the live presentation will appear here:
http://www.meetup.com/Silicon-Valley-Linux-Technology/events/208133972/
While probably the most prominent, Docker is not the only tool for building and managing containers. Originally meant to be a "chroot on steroids" to help debug systemd, systemd-nspawn provides a fairly uncomplicated approach to work with containers. Being part of systemd, it is available on most recent distributions out-of-the-box and requires no additional dependencies.
This deck will introduce a few concepts involved in containers and will guide you through the steps of building a container from scratch. The payload will be a simple service, which will be automatically activated by systemd when the first request arrives.
Kernel Recipes 2015 - Hardened kernels for everyoneAnne Nicolas
Grsecurity is a Linux kernel hardening patch. The PaX patchset it includes pioneered some security features like ASLR which where later included in basically every operating system. But the patch itself is still standalone (not included mainline), so most Linux users don’t benefit its security features.
A lot of people only use binary distribution kernels, and this talk will present some challenges found when trying to provide a distribution kernel with Grsecurity included.
I’ll first quickly present the grsecurity patch, then the attempt to include it in the Debian distribution kernel as a featureset. Finally there will be some pointers on how to provide hardened kernels easily for as many people as possible.
Yves-Alexis Perez, ANSSI
Let's trace Linux Lernel with KGDB @ COSCUP 2021Jian-Hong Pan
https://coscup.org/2021/en/session/39M73K
https://www.youtube.com/watch?v=L_Gyvdl_d_k
Engineers have plenty of debug tools for user space programs development, code tracing, debugging and analyzing. Except “printk”, do we have any other debug tools for Linux kernel development? The “KGDB” mentioned in Linux kernel document provides another possibility.
Will share how to experiment with the KGDB in a virtual machine. And, use GDB + OpenOCD + JTAG + Raspberry Pi in the real environment as the demo in this talk.
開發 user space 軟體時,工程師們有方便的 debug 工具進行查找、分析、除錯。但在 Linux kernel 的開發,除了 printk 外,還可以有哪些工具可以使用呢?從 Linux kernel document 可以看到 KGDB 相關的資訊,提供了在 kernel 除錯時的另一個可能性。
本次將分享,從建立最簡單環境的虛擬機機開始,到實際使用 GDB + OpenOCD + JTAG + Raspberry Pi 當作展示範例。
Systemd: the modern Linux init system you will learn to loveAlison Chaiken
The talk combines a design overview of systemd with some tutorial incofrmation about how to configure it. Systemd's features and pitfalls are illustrated by short demos and real-life examples. Files used in the demos are listed under "Presentations" at http://she-devel.com/
Video of the live presentation will appear here:
http://www.meetup.com/Silicon-Valley-Linux-Technology/events/208133972/
While probably the most prominent, Docker is not the only tool for building and managing containers. Originally meant to be a "chroot on steroids" to help debug systemd, systemd-nspawn provides a fairly uncomplicated approach to work with containers. Being part of systemd, it is available on most recent distributions out-of-the-box and requires no additional dependencies.
This deck will introduce a few concepts involved in containers and will guide you through the steps of building a container from scratch. The payload will be a simple service, which will be automatically activated by systemd when the first request arrives.
This Presentation help you to start your first three programs on Linux. all the codes are taken from another book, and resources. I just make it together.
RAID (originally redundant array of inexpensive disks, now commonly redundant array of independent disks) is a data storage virtualization technology that combines multiple physical disk drive components into a single logical unit for the purposes of data redundancy, performance improvement, or both.
Data deduplication is a hot topic in storage and saves significant disk space for many environments, with some trade offs. We’ll discuss what deduplication is and where the Open Source solutions are versus commercial offerings. Presentation will lean towards the practical – where attendees can use it in their real world projects (what works, what doesn’t, should you use in production, etcetera).
The Unofficial VCAP / VCP VMware Study GuideVeeam Software
Veeam® is happy to provide the VMware community with new, unofficial study guides prepared by VMware certified professionals Jason Langer and Josh Coen.
Free VCP5-DCV Study Guide
In this 136-page study guide Jason and Josh cover all seven of the exam blueprint sections to help prepare you for the VCP exam.
Free VCAP5-DCA Study Guide
For those currently holding their VCP certification and want to take it up a notch, Jason and Josh have you covered with the 248-page VCAP5-DCA study guide. Using this study guide along with hands-on lab time will help you in the three and a half hours, lab-based VCAP5-DCA exam.
Redundant Arrays of independent disks is a family of techniques that use multiple disks that are organized to provide high performance and/or reliability
Performance evolution of raid is a presentation slide about RAID, Its classification, Importance,Concept about RAID,Standard Raid Level,Implementation of Raid, Performance and Advantages Comparison among RAID Levels.
Hope It will be helpfull..................
Demystifying Storage - Building large SANsDirecti Group
From http://wiki.directi.com/x/hQAa - This is a fairly detailed presentation I made at BarCamp Mumbai on building large storage networks and different SAN topologies. It covers fundamentals of selecting harddrives, RAID levels and performance of various storage architectures. This is Part I of a 3-part series
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
2. RAID Storage SystemRAID Storage System
●
Redundant Array of Inexpensive DisksRedundant Array of Inexpensive Disks
– Combine multiple small, inexpensive disk drivesCombine multiple small, inexpensive disk drives
to perform faster than a single physical diskto perform faster than a single physical disk
– Appear to the computer as a single virtual driveAppear to the computer as a single virtual drive
– Support fault-tolerance by redundantly storingSupport fault-tolerance by redundantly storing
information in various waysinformation in various ways
3. RAID TypesRAID Types
●
Many types of array architectures, RAID 1 ~ 6Many types of array architectures, RAID 1 ~ 6
– Different disk fault-toleranceDifferent disk fault-tolerance
– Different trade-offs in features and performanceDifferent trade-offs in features and performance
●
A non-redundant array of disk drives is oftenA non-redundant array of disk drives is often
referred to as RAID 0referred to as RAID 0
●
Only RAID 0, 1, 3 and 5 are commonly usedOnly RAID 0, 1, 3 and 5 are commonly used
– RAID 2 and 4 do not offer any significant advantages overRAID 2 and 4 do not offer any significant advantages over
these other typesthese other types
●
Certain combination is possible (10, 35 etc)Certain combination is possible (10, 35 etc)
– RAID 10 = RAID 1 + RAID 0RAID 10 = RAID 1 + RAID 0
4. RAID 0 - StripingRAID 0 - Striping
●
No redundancyNo redundancy
– No fault toleranceNo fault tolerance
●
High I/O performanceHigh I/O performance
– Parallel I/OParallel I/O
●
Require a minimum of 2 drives to implementRequire a minimum of 2 drives to implement
...
E
C
A
...
F
D
B
5. RAID 1 – MirroringRAID 1 – Mirroring
●
Provide good fault toleranceProvide good fault tolerance
– Works okay if one disk in a pair is downWorks okay if one disk in a pair is down
●
One write = a physical write on each diskOne write = a physical write on each disk
●
One read = either read both or read the less busy oneOne read = either read both or read the less busy one
– Could double the read rateCould double the read rate
●
Require a minimum of 2 drives to implementRequire a minimum of 2 drives to implement
...
C
B
A
...
C
B
A
6. RAID 3 - Parallel Array with ParityRAID 3 - Parallel Array with Parity
●
Fast read/writeFast read/write
●
All disk arms are synchronizedAll disk arms are synchronized
●
Speed is limited by the slowest diskSpeed is limited by the slowest disk
●
Require a minimum of 3 drives to implementRequire a minimum of 3 drives to implement
...
E
C
A
...
F
D
B
...
p
p
p
7. Parity Check - ConceptParity Check - Concept
●
An extra bit added to a byte to detect errors in storage orAn extra bit added to a byte to detect errors in storage or
transmissiontransmission
●
Even (odd) parity means that the parity bit is set so that thereEven (odd) parity means that the parity bit is set so that there
are an even (odd) number of one bits in the word, includingare an even (odd) number of one bits in the word, including
the parity bitthe parity bit
●
A single parity bit can only detect single bit errors since if anA single parity bit can only detect single bit errors since if an
even number of bits are wrong then the parity bit will noteven number of bits are wrong then the parity bit will not
changechange
●
It is not possible to tell which bit is wrongIt is not possible to tell which bit is wrong
...
11100010
01010011
11001100
...
00010111
11101010
00011001
...
11110101
10111001
11010101
8. RAID 5 – Parity CheckingRAID 5 – Parity Checking
●
For error detection, rather than full redundancyFor error detection, rather than full redundancy
●
Each stripe unit has an extra parity stripeEach stripe unit has an extra parity stripe
– Parity stripes are distributedParity stripes are distributed
●
Require a minimum of 3 drives to implementRequire a minimum of 3 drives to implement
...
p
C
A
...
E
p
B
...
F
D
p
9. Hardware vs. Software RAIDHardware vs. Software RAID
●
Software RAIDSoftware RAID
– Run on the server's CPURun on the server's CPU
– Directly dependent on server CPU performance and loadDirectly dependent on server CPU performance and load
– Occupies host system memory and CPU operation,Occupies host system memory and CPU operation,
degrading server performancedegrading server performance
●
Hardware RAIDHardware RAID
– Run on the RAID controller's CPURun on the RAID controller's CPU
– Does not occupy any host system memory. Is notDoes not occupy any host system memory. Is not
operating system dependentoperating system dependent
– Host CPU can execute applications while the arrayHost CPU can execute applications while the array
adapter's processor simultaneously executes arrayadapter's processor simultaneously executes array
functions: true hardware multi-taskingfunctions: true hardware multi-tasking
10. Array Creation withArray Creation with mdadmmdadm
●
mdadm h | helpmdadm h | help
●
An array can be created at install timeAn array can be created at install time
●
Create partitions with type FD (usingCreate partitions with type FD (using fdiskfdisk, or other, or other
partitioning software)partitioning software)
●
mdadm create helpmdadm create help
C | create /dev/mdXC | create /dev/mdX
l | level 0 | 1 | 4 | 5 | 6 | 10l | level 0 | 1 | 4 | 5 | 6 | 10
n | raiddevices # device [...]n | raiddevices # device [...]
x | sparedevices # device [...] x | sparedevices # device [...]
mdadm C /dev/md0 l 5 n 3 /dev/sdd1 /dev/sde1 mdadm C /dev/md0 l 5 n 3 /dev/sdd1 /dev/sde1
/dev/sdf1 x 1 /dev/sdg1/dev/sdf1 x 1 /dev/sdg1
●
Create filesystemCreate filesystem
11. Software RAID MonitoringSoftware RAID Monitoring
●
/etc/mdadm.conf /etc/mdadm.conf
– identify which devices are RAID devices and toidentify which devices are RAID devices and to
which ARRAY a specific device belongswhich ARRAY a specific device belongs
●
mdadm F | follow | monitormdadm F | follow | monitor
●
/proc/mdstat /proc/mdstat
– real-time information and status about softwarereal-time information and status about software
RAID arrays and devicesRAID arrays and devices
14. LVMLVM
●
Logical Volume ManagementLogical Volume Management
– Allow a single volume distributed across more thanAllow a single volume distributed across more than
one physical device, to form a larger file system sizeone physical device, to form a larger file system size
beyond device limitation.beyond device limitation.
– Flexibility on resizing or moving file systemFlexibility on resizing or moving file system, reduce, reduce
down time cost on file system migration.down time cost on file system migration.
●
All file systems exceptAll file systems except /boot//boot/ can live oncan live on
LVMLVM
– GRUB limitationGRUB limitation
– GRUB2 can handleGRUB2 can handle /boot/boot on LVMon LVM
15. LVM ComponentsLVM Components
●
Physical Volume (PV)Physical Volume (PV)
– A single device, like partition, disk, etc.A single device, like partition, disk, etc.
●
Volume Group (VG)Volume Group (VG)
– One or more PVs to form a VGOne or more PVs to form a VG
●
Physical Extend (PE)Physical Extend (PE)
– The basic consuming unit size divided from PVs whileThe basic consuming unit size divided from PVs while
joining a VGjoining a VG
●
Logical Volume (PV)Logical Volume (PV)
– Combination of PEs, can be used as block deviceCombination of PEs, can be used as block device
●
Logical Extend (LE)Logical Extend (LE)
– The PEs assigned to LVThe PEs assigned to LV
28. Device MapperDevice Mapper
●
In the Linux Kernel 2.6, the LVM2 is implemented inIn the Linux Kernel 2.6, the LVM2 is implemented in
terms of the device mapperterms of the device mapper
●
A simple block-level scheme for creating virtualA simple block-level scheme for creating virtual
block devices and mapping their contents onto otherblock devices and mapping their contents onto other
block devicesblock devices
●
Allows its I/O redirection services to be shared withAllows its I/O redirection services to be shared with
other volume managers (such as EVMS)other volume managers (such as EVMS)
●
SAN multipathing provides redundancy andSAN multipathing provides redundancy and
increased throughput, device-mapper providesincreased throughput, device-mapper provides
vendor-neutral multipathing configurationvendor-neutral multipathing configuration
●
Device files are located in /dev/mapperDevice files are located in /dev/mapper