IGNOU4U above all Team has Uploaded above all IGNOU MCA Free Solved Assignments (MCS-022) here especially respecting IGNOU MCA students… MCS-022 Operating System Concepts and Networking ManagementThis Assignment has five questions. Answer all questions. above all Rest 20 marks are respecting viva make known. above all You may functioning illustrations and diagrams to swell the explanations. (b) List and define the numerous features of Bridges with the arrogate of a diagram.
Question 1:(a) What is an IP whereabouts? How is it configured? Write all the steps. (10 Marks) above all abasing above all Answer above all. above all (a) An Internet Protocol (IP) whereabouts is a numerical ID card (logical address) that is assigned to devices participating in a computer network utilizing the Internet Protocol respecting communication between its nodes.
Planning Network Interface and IP Address Configuration above all abasing Follow these guidelines when planning the configuration of the interfaces to the clandestine network between nodes in a accumulate that can be familiar as a check network between nodes (this guaranty is familiar when you delineate the nodes): above all abasing ” Each interface has unhurt IP whereabouts. above all abasing above all ” An IP mode can be specified respecting each IP whereabouts in /etc/hosts. above all abasing above all ” The IP addresses familiar on each node respecting the interfaces to the clandestine network are on a embryonic subnet from the IP addresses familiar respecting every Tom networks.
above all abasing ” Choosing a naming unwritten law respecting these IP addresses that identifies them with the clandestine network can be accommodating. For regulatory, herald the hostname with priv- (for private), as in priv-xfs-ha1 and priv-xfs-ha2. Follow these guidelines when planning the configuration of the node interfaces in a accumulate to unhurt or more every Tom networks: above all abasing ” If re-MACing is required, each interface to be failed at an end requires a dedicated backup interface on the other node (an interface that does not fool a exceptionally mount IP address). above all abasing above all ” Each interface has a embryonic IP whereabouts. Thus, respecting each IP whereabouts on an interface that requires re-MACing, there should be unhurt interface in each node in the failover area dedicated respecting the interface.
The embryonic IP whereabouts does not join forces with disaster at an end. above all abasing above all ” The hostname of a node cannot be a exceptionally mount IP whereabouts. above all abasing above all ” All IP addresses familiar away clients to access exceptionally mount services requisite be as far as someone is concerned of the resource crowd to which the HA utility belongs. above all abasing above all ” Making quality choices respecting exceptionally mount IP addresses is important; these are the “hostnames” that intent be familiar away users of the exceptionally mount services, not the fast hostnames of the nodes. above all abasing above all ” If re-MACing is required, all of the exceptionally mount IP addresses requisite fool the having said that backup interface.
above all abasing ” Make a map out respecting publicizing the exceptionally mount IP addresses to the alcohol community, since users of exceptionally mount services requisite functioning exceptionally mount IP addresses as contrasted with of the create of the hostname fool a ball. above all abasing above all ” Do not configure exceptionally mount IP addresses in unmoving Linux configuration files. Follow the method here to space for on whether re-MACing is required (see Section 1.8.2, respecting guaranty to re-MACing). node1 and node2 can be nodes of a Linux FailSafe accumulate, but they need not be.
It requires the functioning of three nodes: node1, node2, and node3. They requisite be on the having said that subnet. node3 is a third node. If you need to validate that a router accepts unrequested for ARP packets (which means that re-MACing is not required), node3 requisite be on the other side of the router from node1 and node2.
ip_address is an IP whereabouts respecting node1. Configure an IP whereabouts on unhurt of the interfaces of node1:# /sbin/ifconfig interface inet ip_address netmask netmask upinterface is the interface to be familiar access the node. This IP whereabouts is familiar all the modus operandi through this method. netmask is the netmask of the IP whereabouts. From node3, ping the IP whereabouts familiar in Step 1 above all:# ping -c 2 ip_addressPING 190.0.2.1 (190.0.2.1): 56 details bytes64 bytes from 190.0.2.1: icmp_seq=0 ttl=255 time=29 ms64 bytes from 190.0.2.1: icmp_seq=1 ttl=255 time=1 ms–190.0.2.1 PING Statistics–2 packets transmitted, 2 packets received, 0% found apportion lossround-trip min/avg/max = 1/1/1 msEnter this fool a ball on node1 to keep out down the interface you configured in Step1 above all:# /sbin/ifconfig interface downOn node2, make an impression on this fool a ball to excite the IP whereabouts to node2:# /sbin/ifconfig interface inet ip_address netmask netmask upFrom node3, ping the IP whereabouts: # ping -c 2 ip_addressIf the ping fool a ball fails, unrequested for ARP packets are not being accepted and re-MACing is needed to join forces with disaster at an end the IP whereabouts. This whereabouts has a network prove of 255.255.255.0, a announce whereabouts of 192.26.50.255, and it is configured on interface eth0.
Example IP Address Configuration: you are configuring an IP whereabouts of 192.26.50.1. In this regulatory, you are also configuring an IP whereabouts of 192.26.50.2. This whereabouts also has a network prove of 255.255.255.0, a announce whereabouts of 192.26.50.255, and it is configured on interface eth1.shows the Linux FailSafe configuration parameters you denominate respecting these IP addresses. IP Address Configuration Parameters.
Answer (b)… Resource Attribute above all abasing above all Resource Name: 192.26.50.1 above all abasing above all Resource Name: 192.26.50.2network prove above all abasing above all abasing above all abasing above all abasing above all abasing above all 255.255.255.0 above all abasing above all abasing above all abasing above all abasing above all abasing above all abasing above all abasing above all 255.255.255.0broadcast whereabouts above all abasing above all abasing above all abasing above all 192.26.50.255 above all abasing above all abasing above all abasing above all abasing above all abasing above all abasing above all abasing above all 192.26.50.255interface above all abasing above all abasing above all abasing above all abasing above all abasing above all abasing above all abasing above all eth0 above all abasing above all abasing above all abasing above all abasing above all abasing above all abasing above all abasing above all abasing above all abasing above all eth1Local Failover of IP AddressesYou can configure your organized unhurt so that an IP whereabouts intent join forces with disaster at an end to a defective interface within the having said that multitude, respecting regulatory from eth0 to eth1 on a fasten on node. A period is a metal goods painting respecting linking two networks that space for with the having said that memorandum. Unlike a repeater, which works at the corporal even, a period works at the deductive even (on layer 2 in the OSI model), which means that it can strainer frames so that it solely lets biography details whose terminus whereabouts corresponds to a contrivance located on the other side of the period. The period is familiar to section a network, holding quid pro quo the frames intended respecting the nearest apportion network while transmitting those meant respecting other networks.
On the other employee, the filtering carried outside exhausted away the period can insult a perceptible moratorium when effective from unhurt network to another, and this is why bridges requisite be carefully placed within a network. This reduces freight (and above all collisions) on all networks, and increases the even of monasticism, as guaranty intended respecting unhurt network cannot be listened to on the other goal. A bridge’s discriminating capacity is to send packets between two networks of the having said that group. ConceptA period has two connections to two well-defined networks.
When the period receives a snare on unhurt of its interfaces, it analyses the MAC whereabouts of both the sender and heir. This modus operandi, the period can smudge outside exhausted if the sender and receiver are develop on the having said that side or contrasting sides of the period. If a period doesn’t recognise the sender, it stores its whereabouts in a provisions in fellowship to “remember” which side of the network the sender was on. If it’s the after, the period ignores the message; if it’s the latter, the period sends the snare along to the other network.
How to WorkA period works at the details communicate with layer of the OSI embryonic, assets that it operates using the corporal addresses of the machines. In actuality, the period is linked to not too nearest apportion networks, called segments. When details is transmitted, the period checks the space for as provisions respecting the section the sending and receiving computers confined to to (using their corporal whereabouts, called the MAC whereabouts, and not their IP address). The period creates a space for as provisions with the machines’ addresses and the segments they confined to to, and “listens” to the details continual in every modus operandi the segments. If they confined to to the having said that section, the period does nothing; below other circumstances, it switches the details at an end to the terminus computer’s section. What is the functioning of a bridgeThe period is familiar to section a network, assets that in the diagram shown on, communication between the three computers on lid intent not cessation up the lines continual between the three computers on the arse.
The guaranty intent solely pass in every modus operandi when a computer on unhurt side of the period sends details to a computer on the other side. Question 2:(a) Explain the mapping scenario of understood whereabouts to corporal whereabouts. What’s more, these bridges can be linked to a modem, so they can space for with a perceptible nearest apportion network as famously.
10 Marks. (b) Describe the page-boy replacement and page-boy allocation scenario in Linux.5 Marks.. Answer (a) 1. Each approach has a lean called “global directory” which maps the directory-field to a “page midway directory”. Virtual Addressing above all: Linux sees a understood whereabouts as consisting of four fields: The directory- middle- page- and offset-field.
The directory-field indexes the entrВe in this directory, which in resort to b advert to maps to another lean called “page table”, which when indexed away the value of the page-field, at the after substance maps to a page-boy in the corporal memory. The counteract specialization addresses the desired memory corner affiliated to the page-boy put. Why all the double-cross with triple indirection?, you may assemble inquire. BOTH ARE SAME ANS2. The functioning one’s judgement is, that the “page midway directories” and “page tables” are themselves memory pages, that need not to be kept in memory, unless they are in allude to of in allude to of fact needed.
Page AllocationWhen a approach requests memory, Linux allocates it the following modus operandi: It splits the full memory in halves, and splits unhurt half again and unhurt of that quarters again, and so on, until the chunk is justified consequential passably to keep going the amount the approach requested. If a approach relinquishes it’s memory chunk, these may be rejoined with another chunk, if they were split up put in penmanship over from. This is called the “buddy algorithm.”3. g. Page ReplacementThe Page Replacement Algorithm in Linux is a unstable of the Clock Algorithm, e. it iterates over again at an end the memory pages, like a clock employee iterating at an end the numbers on its be seen. In Linux, each memory page-boy as an epoch capricious which gets incremented when the page-boy is familiar.
When a page-boy appropriate respecting replacement is searched, the iteration starts, and decrements the epoch variables of the pages unhurt after another, until it encounters unhurt with epoch zero. PageReplacementDesignIn blunt, the commonest page-boy replacement contrivance in Linux (up to and including 2.6.24) has two problems: above all abasing ” Sometimes the nut evicts the defective pages, resulting in lugubriousness prove. This page-boy is then replaced. above all abasing above all ” The nut scans at an end pages that should not be evicted.
This results in increased CPU functioning on at quickly memory systems (several GB), but results in catastrophic CPU functioning and incarcerate contention on immense systems (>128GB of RAM). High even overview above all abasing ” Evicts pages with smallest scanning. above all abasing above all ” Most page-boy churn comes from reading at quickly files. Systems with 1TB RAM abide, the VM cannot fool the means to overview pages that should not be evicted.
Evict those pages to begin. above all abasing above all ” Evict other pages when we do not fool passably memory respecting readahead or we hold in check reading in the having said that guaranty details at an end and at an end again. above all abasing above all ” Filesystem IO is much more skimping than swap IO. above all abasing above all ” Use note and refault details to assess filesystem stockpile and anonymous (process) memory.
Only boot outside exhausted guaranty stockpile if we can. above all abasing above all ” Optimize the discriminating case; also optimize the worst encase. The VM requisite be powerful at all times, so the worst encase has to space for famously too. File stockpile above all abasing ” Contains disk and network filesystem details and metadata. above all abasing above all ” New pages start on the languid lean. above all abasing above all ” Page replacement entirely compare favourably with to the commonest 2.6 nut algorithm.
above all abasing ” Pages that advance familiar multiple times are promoted to the in extract lean. above all abasing above all ” Pages that got familiar now (or never) are reclaimed. above all abasing above all ” Sizing the in extract lean could be done enhance with details on recently evicted non-resident pages, which we lack respecting other purposes anyway. ” above all abasing above all Need to wizen page-boy scanning:” above all abasing above all Typically consumes a plaintiff of memory. Anonymous memory” above all abasing above all Contains memory from processes, shared memory segments and the swap backed filesystem (tmpfs). ” above all abasing above all Only swapped outside exhausted fixed on uncountable systems. ” above all abasing above all Every anonymous page-boy starts outside exhausted referenced.
” above all abasing above all Solution: SEQ replacement. ” above all abasing above all Referenced pages advance deactivated too. ” above all abasing above all Always excite pages from goal of in extract lean to languid lean and direct referenced improper. ” above all abasing above all Limits the highest plaintiff of pages that need to be scanned to twice the magnitude of the languid lean.
” above all abasing above all Inactive lean should be a within reason magnitude. ” above all abasing above all Large passably to employee outside exhausted pages a off the cuff to be reused. ” above all abasing above all Small passably to limit the highest amount of space for the VM needs to do. ” above all abasing above all Needs some unperceived aging, to scram starting fixed with FIFO replacement. ” above all abasing above all Maybe 30% of anonymous pages on a 1GB organized unhurt, but 1% of anonymous pages on a 1TB organized unhurt?” above all abasing above all Most of the in good time we boot outside exhausted guaranty pages, the anonymous pages advance scanned almost never. ” above all abasing above all When there is no unchain swap hiatus, do not overview.
Non reclaimable” above all abasing above all Contains mlocked processes and mlocked shared memory segments, as famously as ramfs and ramdisk pages. ” above all abasing above all At munlock in good time, it is moved to either the guaranty or anonymous lists. ” above all abasing above all When a page-boy gets mlocked, it is added to the non reclaimable pond. ” above all abasing above all Non reclaimable pages are not ever scanned. Recently evicted / nonresident” above all abasing above all Does not keep going realized pages, solely guaranty that the page-boy was recently evicted.
” above all abasing above all Implemented with entirely gross hiatus on high. OOM killer” above all abasing above all Currently, Linux has a definite in good time figuring outside exhausted accurately when it has be familiar up outside exhausted of memory. Can flush in the page-boy stockpile radix tree. ” above all abasing above all Knowing accurately how much memory is filesystem backed and how much is swap/ram backed intent arrogate us. ” above all abasing above all When swap is broad, memory is broad and the amount of filesystem backed memory is exceptionally gross, we need to OOM prey something. Merge plan” above all abasing above all Split up into a pad series (done, intent need some reshuffling). ” above all abasing above all Non reclaimable pond.
” above all abasing above all LRU array framework. ” above all abasing above all Split into file/anon with trivial balancing framework. ” above all abasing above all Non-resident (recently evicted) tracking. ” above all abasing above all SEQ replacement respecting anonymous pages. ” above all abasing above all Make the OOM assassin faster, using the exam on.
” above all abasing above all Clockpro-like replacement respecting guaranty pages. ” above all abasing above all Andrew and Linus can fill someone’s needs the least polemical bits to begin, with no need to advance the unhurt applied at now. ” above all abasing above all Improve the VM stride in keeping with away stride in keeping with, fixing more corner cases at each commingle. ” above all abasing above all Makes incremental testing away a at quickly community doable. This has a plaintiff of reasons:” above all abasing above all Pages are swapped outside exhausted in an LRU-like latest thing. Old page-boy contentsDesign tenets” above all abasing above all File IO is fundamentally more skimping than swap IO.
File cheerful as a rule is already on disk; we can permit to outside exhausted in a continue the page-boy without IO. ” above all abasing above all Multiple rounds of malloc and unchain can keep company up double-cross memory. File contents are as a rule interdependent, so we can do skimping readahead. ” above all abasing above all We fool to allot with systems where swap is insignificantly negligible, eg. ” above all abasing above all Swap administration in Linux is entirely uninvolved (also gross overhead). a database server with 128GB RAM, 2GB swap and an 80GB shared memory section.
” above all abasing above all We cannot rob our in good time scanning 100GB of anonymous memory, to advance at the 8GB freeable page-boy stockpile!” above all abasing above all We need analyse pageout extract lists respecting anonymous and guaranty backed pages. ” above all abasing above all Belady’s MIN “algorithm” needs to be modified. Instead, the aspiration is to wizen the plaintiff of IO operations required. A page-boy replacement algorithm does not fool as its embryonic aspiration to wizen the plaintiff of page-boy stockpile and anonymous memory misses. ” above all abasing above all If we hold in check some statistics, we can gage accurately how much more skimping guaranty IO and swap IO are, respecting the workload that the organized unhurt is currently continual.
” above all abasing above all Using those statistics, in compounding with other guaranty, we can efficiently magnitude the “LRU” pools respecting anonymous and guaranty backed memory. ” above all abasing above all If there is no swap hiatus we do not attempt to wizen the anonymous memory pond. ” above all abasing above all We need a overview impervious algorithm (see ” above all abasing above all AdvancedPageReplacement) to selected which pages to unchain. ” above all abasing above all Since the embryonic split is on “IO cost”, memory mapped pages (except shared memory segments) outside exhausted in a continue into the guaranty backed pond.
Design details” above all abasing above all One found of pageout extract lists (LRU, CLOCK-Pro,.) respecting anonymous pages and another unhurt respecting guaranty backed pages. ” above all abasing above all We assess the magnitude of the anonymous and guaranty backed pools according to these criteria:” above all abasing above all IO evaluation to put in penmanship over from and refill pages from each pond. ” above all abasing above all How actively familiar are the pages in each pond?” above all abasing above all Ie.