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CAM Target Layer

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CAM Target Layer
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functionality unit ones drivers part Bugs mathematics Hardware Rank framework CAMS Blocks provide smart drivers SCSI words emulations Render framework Right Video Blocks simulation modes
Free lines sources similar part energy product versions mathematics logic framework structure CAMS systems Silicon Graphics Inc. sources code stacks lines open subsets product similar logic topology system versions level
Context files views sources ones part digital communication number data management mechanisms Types memory different kernel Hardware queue matrix file system framework disk report platforms tasks Silicon Graphics Inc. Context multiple simulation Blocks high availability attributes instance processor SCSI Types words data management kernel emulations logic communication orders Right tasks modes
point bottom files directions drivers sets part Codes Stripe peripheral devices different memory file system level box testing normal CAMS tasks Blocks staff system call several theory caches kernel ISP processes case organization Right CDROM figure write data integration
SCSI injectives time unit ones sets Contracts part programs CAN-bus mathematics rates different file system box framework series descriptions exception systems injectives area generate Development completion Types configuration normal website testing Right sort Results track statistics functionality Free studies drivers raids prototype naturally bandwidth Hardware utilizes testing encoding CAMS form default distribution percolation SCSI residual kernel errors Hardware band Abstract
Terminal demo BUS
reading SCSI presentation injectives files ones functions virtual reality terms Direct testing HDDs information disk CAMS errors report Development Kit data types injectives Serialization unit Blocks transfer fields directories lines Continuation SCSI number specific message-based errors case input life testing conditions Right figure objects Blocks reading
injectives laptop Steuerwerk response bottom ones sets part SCSI errors conditions pattern CAMS errors systems
Mutual Blocks ones Continuation
reading write processes total utilizes total systems write reading systems training
pulse functionality statistics modules files time Flash unit formating machine drivers water The list part powerful Twitter training image goods framework processes model structure CAMS Allocation Arc multiple formating forces NET moment The list effects high availability staff drivers variables statistics multithreaded words processes communication buffer procedure simulation structure Arc
in Spectra Logic Corp. and were hiring if anybody's interested party efforts so what is the CTL CTL target
framework it can preserve renders or flower block devices part fights in one's a logical units only visible through a target capable so the only 1 that is fully 100 per cent functional right now starts bugs that pretty well there is I asked the driver so the word specifically for DAQ like arbitral cards work pretty well of anything else is the same it it has started modes where there's some lighter can't API changes gone so in this drivers probably need the usual ones are also available through an internal CT also at the economy a device driver and that allows you to use it show that actual hardware so
originally I wrote overcoat pen system starting 2003 it was really written for Linux in because I helped write him a city or actually have a lot of similarities him as a lot of structural commonality there in and actually put thousands of lines of can inside the fuel in the Linux version in Richland that Cook and Pople with this topic the I stack and later a change that's Akopian part where it made more sense and it's been shipping since 2005 incomplete products and when they ported they're stacked if reduced in 2008 a port city along with it as it will rip out a bunch of the Concord Texas was no longer necessary at this used it directly and it's actually currently shipping and co-parents SGI or 30 and 404 energy products of look on the website see as in previous debates products they're using to kill
in ways he still get source was copious assets were bought by SGI in 2010 and spectral Logic my current emitted deal with best GIT source under a BSD style licenses and the intent behind the agreement was that spectra would work together Si-cheol in the 4 years the so thanks to SGI and Spectra Logic we have a more full-featured part framework in in the tree the when it's in previously had several minus of several earlier this year so some of the features of that has
just been processed advice simulation a tag queuing pass-catcher which support so you can do crack support for automated usable tags as the implicit minoring in what I mean by that is a so you have a mode select followed by right well you won't block the right Toeplitz select completes because the mode select may do something better affects the execution of right and so you have to implicitly treatment selectively word commands this stack and so it has a whole matrix of the 1st and 2nd command types of fines in a 1 command of type X in the queue and there's another command type y following it them controls whether you the following command will to able to keep going whether get what as full task management work for all different because cast contributes abort 1 reset part reset button reset everything like that that's pretty full-featured in that regard for multiple ports so you can have any number of front in ports you can 10-Q logic caja any other kind of part 1 from the multiple initiators logging in a multiple 1 street pretty much as many ones you like so many of you have memory for the multiple back and types of right now we have a RAMdisk a block and file back and you can have ones from a B. the back types all in their simultaneously it also has a
persistent reservation support and this is a very handy for the multiple initiator scenarios only and in a very necessary for that remote sensing what's like support and all I was handled inside the kernel so there no usually context switches I even though copying another kernel that that's pretty quick in that regard and there is basic high-availability support and the reason it is not complete It's because when we got the CTL sourced from SGI we did not get the source of the whole HA framework and even if we had it would have been very but of all the freest in general it's very specific to their hardware platform so in order to make a high-availability useful what we would need to do is actually put in a framework a communication mechanism in place that would in report probably replace the stubs of whatever our view oligopoly communication framework it's got that set up essentially to do of active active high-availability between 2 nodes that doesn't really do more than 2 nodes right now it has the ability to do the data transfers in between 2 sit CTO instances directly or implicitly so if say you're on top of a clustered file system and clustered file system is doing the memory mirroring in between instances and held that as well so the 2 different HA modes in there and you can see that i in the custody go stick around so this is
the structural way out of him in a show how it relates to see geologists 2nd but so up at the top in a have usually only have read write narcosis calls is it going to be the DEA direct access to CD-ROM in Essays sequential-access for K crowds stripes so this that's the peripheral driver levels 1st layer inside the kernel and then down below that as the Canucks beat your transport layer and that's the main players can that wraps all commands through from the top to the bottom down the bottom level is somewhere or the device driver layer here and I see that I aced Hinnant yes drivers there the others just to a ton of different device drivers here so this is the basic can structural way out there when he had CTL the picture
here's what it turns into so there's a lot more staff in so at the top you see the CTL peripheral driver just side say don't wanna hear of don't look at other point I make this thing work but anyway by of the side of the essay drivers CTO peripheral driver and that's where most of the commands can but there's also an internal initiator some driver down at the bottom CCT him that's that CTL has hit the top there are 4 front imports so there are several front and ports there's the main command execution part of it that decodes AlDS because it means does all the basic processing in the bottom the back alike the block and file back in which is what you use to us so on top of that deal in any DOS device any file file system and around us the RAM this is the take in the sense that of it just that passes the data the idea is that you can have a red this committee size you want it only has a megabyte of memory backing it and I would just go straight through and so it doesn't really stated so it's not for data integrity testing mainly for battle that's OK it's secure it is how and normal command would come and see younger acts here and organ assuming in this case that it's coming and by other like driver or a private show that starts off in the sand bottom left and then goes in the ISP driver then comes in can transport layer and then comes and CTO all of peripheral driver was the target prayerful drivers in any can have initiator peripheral drivers like DA in see an essay and past a driver making it part of peripheral drivers like this and so this is the chart prayerful driver him then from there it goes into C kill itself and this is where the task as he commenced get coded figures out as a it ready reader write an inquiry you know what is it that's where figures about but also codes of which 1 it is and therefore which back and goes to is in this case it's going to the block and file back and from there it goes out to whatever your backing store is the figure 1 this is the normal command and so for the internal initiator and this is what you use if you don't have any actual physical part in your box due to use the CGO here's what happens so you start often user when or in a file system due to read write and were impossible in our what really reader right and will go into the DA driver just like any normal I would and then you go to the camp transport layer but that and then it gets routed belong to the set which is right here the CT also which it's a Friday work in in this the and then from there it's rotten to the main parts each over the and it's coated in Benigno's the block and file back in in this case can get around us so to get executed at the debts the interesting thing is you actually wonder going back through so in this case you go back into the DA driver probably mean it's in your own can device in through the transport layer and then say out through the MPs driver and down onto the desks so the next couple trips through him in this particular case so this
is usually so that CTO lady and talks to an IOC see Killian as the primary configuration utility for that CTO results also statistics program called he kill stack see Killian as the primary wait in configure ones in kind of it's got a whole bunch of different functions there's all kinds of things only the newest robins utility and get through the eye Apple for import to separate from the port in the CTO then you under the command decoding and and say it's a reader right you go walking fall back so how can you see kill
there are a lot of different ways to use it the predator 3 D is the box and the natural rate box and this is used it originally in they're still using it and anybody can do this I need 5 Achille part right now and a year later on hopefully other types parts but that's gazillions of Serie so you can do the injection testing so last fall and implemented descriptive study descriptor said support for can in previous the this was precipitated by the we found so 3 terabytes Seagate's abstracts by default had a scuzzy descriptor sets enables and stricter sense for those of you not familiar with it is just a newer form of error reporting for Scuzz it's you know I got a more modular approach this is a different way of reporting errors and so we had to support this because the devices have turned my fault and so because of that actually wrote all this until supports all the target sites were prescriptive for generating distributions 1st so I wrote my tests 1st and then I wrote all the support and can itself on initiator side how to interact with the target side in San Jose will write a complete set of tests for descriptor sets and verified everything works correctly at the same time also affects the lot of sense residual handling the kernel was not modest struggle and the in a fixed a lotta drivers that were not properly handling since residuals in all this I was able to prototype and test is with CTL in ways that would not have really been possible if I had had a a regular distracted just can't get all those areas out of normal distress and so you can do you know with the scuzzy testing without actual scuzzy hardware so if you wanna do it on your laptop and at the you can totally do you get a full scuzzy decoding thing in there I HPA's band with testing with around us back in and prototype new OS features previous developers under contract with the foundation track as this done some interesting work with growth fast and he's been using CTL as it was test framework as you can go and here he wrote the changes to increase the size of a 1 and then generate unit attention the DA driver notices and it's all percolates up the stack and then is able to go grow the file system after the that this device increased the size that is able you see kills of prototype prototyping system work so there's a lot of stuff you can do even if you're not trying to build an extra or a box that you can use it for testing all sorts of other stuff so a little
demonstration of how you configure it means a little but what you can do with it see it
so right here and but little wide terminal here on a small screen so I have a free BSD and it's a running 9 and what was the devices in you see the CTO at him bus the
the see the CTO can there and that's the internal so so if you are going to create a new 1 and the created with Ramdass back in and what's I created with a very large size has been so that's 1048 576 a lot of zeros in terms of but that's why 2 megabytes kit which 1 but anyways the adding zeros it doesn't really matter you just do that an atomic earlier bytes OK it's I created around this there and now going you of create only but what about it's block back the various and in this case I have the 1 terabyte file 1 gigabyte file I think the sitting in my home directory that I just used to create that the test this files right there OK so now I can now take a look at my the ones said CTO all using the Devils commit and I can see that 1 but remember this of black and 1 by the block back and and now what I need used that my ports along normally a new figure CTL it doesn't come up with reports online it comes up with offline because you don't want to preserve all your lungs you know what presenter lines and until your work and until they're all that you know incrementally as the initiator usually does 1 read the report what's so a trend on and there there it is and chemical that was you can do in the in the the off around us I do things like that inquiry in produced kill does tending its speaker megabytes segment I can do things like error injection OK so this is a kind of complicated their objection that set using descriptor sense this is 1 of the things I used just a descriptor sets so OK and then I get this interesting error message here and you never see anything like this in real life this is all custom infected scuzzy sense data that I just shut down there only another thing you can do so this particular test will say OK on a read I want you to return a medium there and I'll want you to return the medium there for certain LBA right and that's what an injector and then OK so get input output here after reading from the device and do the message m
and what you see here but mediator so that was kind of of OK so you can
see the meaning weird and bottom so you can set patterns than responses in error ejection so that's an example error injection in this is all the laptop but when we show
you actual part were so this is a previously system talking to produce the target back in Colorado and other connected by the like Fibre Channel have got a bunch of ones a here previously once you
consider tons of then these are all virtual ones are some of the RAM and some of you actually block devices one's 23 24 hour of the 1st night user 319 your block devices so you can do
things like you but as you said to the first
one that in this read off of this
is reading offered us than the other and 1 and then we show you what looks like the target Sabathia budget by so we have
training 13 15 wanted the going on around here OK so I just started a bunch of beauty processes and then over here see comes the CTL stacked utility and you can see I'm getting in a occurred in something megabytes a 2nd and out of it so anyway you can see the read write total throughput was CTL step and that gives you an idea of what your overall system was this way and it's
back over here their own so go
for broke worked at the list if he thinks we need to do a procedural thing there's prophylactic could do that and is the Goldwasser model right now it's got some issues with on-load retain the doesn't fully clean everything that he's effects we are used of staff or statistics collection right now that uses of of successive collection set up that I invented myself like I said this was originally written for Linux so I had to kind of reinvent the wheel turned and that's that of other things that are just in other words there and Linux as the EFS or back in force he and that would allow us to do not have to copy data into the Ark if we're will this allocate arc buffers India may directly into and out of the price the things that will that will more efficient so use can see see these instead of a city or a structure that would keep from having allocate another unit of I IO as we go down through the stack the flesh out high-availability support part but that earlier allow sending status back with data the final data on reads and at speeds that lowers the latency getting higher I hops of reader multithreaded CGO joke command processing again it's about higher I hearts I end users more standard SG was format and more driver support so questions but on the power follow it down that would be good to do yeah Witten it's been interviewers I got to put that in there but yes we should be the sorry the question was how are we going to do what scares the unmapped support for CTL and answer is yes we should and vowed enter somebody wants to do right now you know I have kind of variable amounts of time and work on it just depends on what in my water has been doing at the moment sometimes I their work on its offense but working on something else but this talk yeah yeah so what's out there that are out there talking about those that he and I discussed a putting CTL on top of fusion I words in the fusion of words do support from or on that same idea and so we would want to be a will pass the Triborough Netcom in all the weight and the fusion works very important for flash devices they have that but work correctly and and we have a training run that coming as a fast so in hopefully we can get it through our entire highest externality indispensable good work on that idea driver of women get through the whole sex at all in when yeah so there that is why pulse of the benefits to having trend through the entire stack and if we can get trim going all the way up and down and then we can free up files on virtual machine images as well because of so why doesn't work or to what yes yeah I communicate between well the problem is there's no communication framework so we got its start there's a stud ied API is defined the nothing was sent essentially what I did is I took the Akopian HA collapse and I made them you know note functions in a justifying about nothing all it could be I I have up to date the true that haven't looked in past to see if it if it would map well know so but past maybe 2 maybe the solution it may be that we in that the CTL put CTO and do communication between I don't know I haven't looked at it so I'm not sure other questions thank you very much at
pH I can freely