The following is the modified chat log portion of a live demo for an IBM BladeCenter and DS4000 Question and Answer session. JonathanD led the session.
[@JonathanD] I’m a certified expert in IBM bladecenter.
[@JonathanD] I’ve installed several dozen DS4000 units.
[Attendee2] JonathanD: mind if sidetrack some of your DS4000 time torward the DS3200 ?
[@JonathanD] Attendee2: I’d prefer to do that one next week, after I’ve installed one
[@JonathanD] I’d really need Brian here, if we want to do it today
[@JonathanD] and I don’t think he’s available right now.
[Attendee2] but most of my questions about LUNs and arrays would be the same anyway right ?
[@JonathanD] Attendee2: yeah, they should be.
[@JonathanD] everyone in VNC?
[@JonathanD] So, does anyone need to know more about the basics… what a SAN is?
[Attendee3] I don’t, mostly.
[@JonathanD] I’ll go over some of the very basic stuff anyway, just as a refresh and in case anyone needs it.
[Attendee2] JonathanD: is this sotrage software the same, regardless of the model ?
[@JonathanD] Attendee2: for the 4000 series, yes.
[@JonathanD] this is what you would see.
[Attendee2] ok it looks very similar to the DS3400 software doc
[@JonathanD] so, what makes a SAN different from a NAS…
[@JonathanD] Attendee2: it is
[@JonathanD] a NAS is a network share, basically, like a windows network share. different machines can use it, and store things there. You can use it with normal networking hardware, nothing special.
[Attendee3] SAN attaches via high speed fiber to a server, whereas a NAS connects via Ethernet?
[@JonathanD] A SAN, generally, is seperate, on it’s own network, and doesn’t have shares.
[@JonathanD] It has LUNs
[@JonathanD] which are assigned to hosts.
[@JonathanD] a LUN is a Logical unit number. to a server, a LUN is a physical disk.
[@JonathanD] on a scsi bus, each drive is a LUN.
[Attendee2] can any one disk (or array ) be split into multiple LUNs ?
[@JonathanD] Attendee2: yes. We’ll take a look at how that works in a moment.
[@JonathanD] so, a LUN, presented to a host, is functionally the same as a physical scsi disk installed IN that host.
[@JonathanD] thats the single biggest difference between SAN and NAS.
[@JonathanD] so, lets take a look at our san here.
[Attendee1] JonathanD: Try not to click around without giving at least a sec or two.
[Attendee1] We won’t be able to follow the screen updates.
[Attendee3] but the ds4k series doesn’t use scsi, it uses SATA?
[@JonathanD] this is a demo system. It has 2 drawers, one with 16 SATA drives, one with 10 FC drives.
[@JonathanD] Attendee3: it uses SATA or FC. FC is funtionally equiv to SCSI
[@JonathanD] from a performance perspective
[@JonathanD] but all these disks are connected to the 4000 via fiber
[@JonathanD] so, you can “see” the disks right now, right?
[Attendee2] and to the hosts via …. ?
[@JonathanD] Attendee2: fiber
[@JonathanD] on the right, we have luns.
[@JonathanD] we’re going to look at how you create a LUN and where it comes from
[@JonathanD] everyone ready?
[@JonathanD] I have about 600GB of unconfigured Fibre disk space.
[@JonathanD] as you can see.
[@JonathanD] thats those 7 drives which currently have little purple things under them.
[@JonathanD] you can see here the drive selection and raid options.
[@JonathanD] we’re going to create a 3 disk raid 5, right now.
[@JonathanD] which will give us 135GB, after parity.
[Attendee1] What’s enclosure loss protection ?
[@JonathanD] someone let me know if I’m going to fast for updates.
[@JonathanD] Attendee1: consider the following.
[@JonathanD] You have a DS4000 with 8 enclosures.
[@JonathanD] (that is, disk cabinets)
[Attendee2] like expansion units ?
[@JonathanD] you build your arrays, as 8 disk raid 5 arrays, going vertically down the cabinets
[@JonathanD] yes, Attendee2
[@JonathanD] so disk 1 in each is part of array 1, disk 2, array 2, and so on.
[@JonathanD] if you lose an entire enclosure, somehow, you still are online.
[@JonathanD] as you have lost only one disk from each array.
[@JonathanD] that is enclosure loss protection
[@JonathanD] losing an enclosure is a RARE thing, but if a customer does have enough enclosures to do this, we will do it.
[@JonathanD] otherwise, it’s considered minor.
[Attendee3] Ah. So that little notification is telling you if those drives are located on different enclosures?
[@JonathanD] Attendee3: well, it’s telling me that TOO many drives from this array are in the same enclosures.
[@JonathanD] you can do loss protection with only 2 enclosures, too.
[@JonathanD] with raid 10
[Attendee3] makes sense. You’d need three enclosures to do raid 5
[@JonathanD] so now,wwe’re looking at the next screen. here, we define the lun size and name.
[@JonathanD] Attendee3: correct.
[@JonathanD] enclosures failing is pretty unlikely, anyway.
[@JonathanD] each has redundant power, and 2 ESMs, which are the devices that connect the drives to the controllers
[Attendee1] Okay, so here you are defining logical/virtual disks carved out of the array you just created?
[@JonathanD] Attendee1: exactly.
[@JonathanD] lets make 2
[@JonathanD] so, an array can be used by more than one host.
[Attendee2] thats perfect
[Attendee1] So you could if you wanted, make the whole thing 1 giant RAID 5 + hot spares, and carve luns out for various uses, right?
[@JonathanD] Attendee1: yes, but that would be a bad idea for more than say, 8 drives.
[@JonathanD] Attendee1: raid 5 rebuild time increase rapidly past 8 drives.
[@JonathanD] a rebuild that took 2 hours on 8 disks could take 8 hours on 10
[Attendee1] So like a 20 drive RAID 50, or RAID 10 would be okay right?
[Attendee2] thats really what i wanted to do was 2 RAID5 arrays and split out 3 LUNs per array to take care of my 6 blades
[@JonathanD] Attendee1: both would probably be fine.
[Attendee3] seems it’d be a better idea to create multiple raid 5 arrays and carve them out as needed.
[@JonathanD] so what were looking at now is LUN characteristics
[@JonathanD] the segment size, cache prefetch, etc.
[Attendee1] The radio buttons do what? Auto suggest geometry?
[@JonathanD] Attendee1: yes.
[@JonathanD] we generally go with cache read prefetch on, and 256 for segment size for mixed workloads
[@JonathanD] unless you have an app making small writes, it’s a good fit
[Attendee1] So like a webserver, you might use smaller segments, right?
[@JonathanD] controller ownership defines which controller owns that lun.
[@JonathanD] Attendee1: a webserver with lots of small files, sure.
[@JonathanD] 64K might be good
[Attendee1] Where webpages are typically under 20k.
[Attendee2] ok well what about something like an exchange DB ? that writes a lot of small things but large things consistantly too
[@JonathanD] 256, Attendee2
[@JonathanD] best for mixed loads like that
[@JonathanD] 128 would be acceptable too
[Attendee2] so i dont really want to use the DB radio ?
[@JonathanD] you can change it, after install
[@JonathanD] you can, Attendee2
[@JonathanD] it picks 128, which would be fine
[@JonathanD] generally you want “map later” here.
[@JonathanD] mapping to default only applies on DS4000 connected to a single server or cluster
[Attendee1] What’s a storage partition?
[@JonathanD] Attendee1: a storage parition is a segmentation of the storage system.
[@JonathanD] without ANY, all hosts see all luns.
[Attendee1] So, it’s used to divvy up luns for connecting computers?
[@JonathanD] the 4000 supports up to 64
[@JonathanD] a cluster with shared disk uses 1, not 1 per node.
[@JonathanD] since all nodes need the shared disk
[@JonathanD] so, we have 2 luns now
[Attendee2] Did you mean to put that on a diff controller ?
[Attendee2] I think you used A for the first one.
[@JonathanD] it automates back and forth
[@JonathanD] ideally, you want to balance between them.
[@JonathanD] you want equal load on each controller
[Attendee2] so if i have 4 LUNs in an array i want 2 of them to be on one controller and 2 on the other
[Attendee2] well i think ill end up with the single controller 3200 so i shouldnt have to worry about that !
[@JonathanD] (this is the san switch)
[Attendee3] Ok, what are you doing here?
[@JonathanD] well, typically we would do zoning here.
[@JonathanD] we don’t need to, because they are already there.
[Attendee3] define zoning for me, please.
[@JonathanD] zoning determines which blades and servers are allowed to see which storage systems, and tapes, and other FC things.
[@JonathanD] it’s similar to VLANs, in ethernet networking.
[Attendee1] If I remember correctly fiber channel is an explicitly defined network if you will.
[Attendee1] Not automatic like normal TCP/IP networks.
[@JonathanD] as you can see here, our HS21 blade can see DS4700_A1
[@JonathanD] which is port 1 on controller A of the 4700
[@JonathanD] here we have the masks.
[Attendee1] Can you also do RADIUS or other authentication?
[@JonathanD] no, theres no provision for that in fiber channel
[Attendee1] Is each blade in a chassis an available endpoint?
[@JonathanD] you can see here, we have an HS21 and an LS21 blade, each with it’s own ports defined
[Attendee2] and the hosts will autodetect from the chssis to the SAN switch ?
[@JonathanD] Attendee2: basically. once the zone is in place.
[@JonathanD] the 4000 sees the ports, you tell the 4000 which ports belong to which host
[Attendee1] Okay, what are we doing now?
[@JonathanD] note: this blade has NO internal disks
[@JonathanD] now, we’re going to put our new luns on a blade 🙂
[@JonathanD] and a windows boot lun, as well
[@JonathanD] I’m just taking off the existing linux boot lun and shared lun
[@JonathanD] so, we just added the lun “HS21_Lun0”
[Attendee1] gvstg01 is what kind of device?
[@JonathanD] as LUN0
[Attendee1] Is that the switch?
[@JonathanD] a ds4700
[@JonathanD] no, it’s the storage system.
[Attendee1] Okay, so it’s the FC controller we configured earlier?
[@JonathanD] right, we’re still on it now
[Attendee1] Host HS21 is the chassis w/ the blade we are trying to setup right?
[@JonathanD] so, I’m adding the 2 luns we created earlier
[@JonathanD] HS21 is the specific blade, in the chassis
[@JonathanD] in this case, blade 2
[Attendee1] Okay, so the specific blade.
[@JonathanD] I just added the 2 luns we created, as luns 1 and 2
[@JonathanD] and you can see them in the list here.
[@JonathanD] except I added them to the wrong host 🙂
[Attendee3] changing them seems easy enough.
[Attendee3] did you do that on purpose? 🙂
[@JonathanD] hehe, catch on quick, Attendee3 🙂
[@JonathanD] so here is our HS21
[Attendee3] I’m wise to the sneaky demo guy tricks..
[@JonathanD] and we’re going to hope that nobody changed whats installed on that Lun0
[@JonathanD] cause if they did we’ll have to install windows 🙂
[@JonathanD] tis the danger of an open lab 🙂
[Attendee1] So, does this device support snapshots of luns?
[@JonathanD] you can see we have 3 luns, the 3 we just added.
[@JonathanD] Attendee1: you can make a flashcopy, yes.
[@JonathanD] it’s 100% space though.
[@JonathanD] and it’s a cost option
[Attendee3] What is a flashcopy?
[@JonathanD] duplicates a lun, Attendee3
[@JonathanD] you can duplicate it to a DS4000 elsewhere, too
[@JonathanD] I just configured us to boot from lun 0
[@JonathanD] if all is well, we should be able to reboot into windows.
[Attendee2] so say i have a LUN with server 2k3 on it, i can just copy that to another LUN that i intend on using for another host for the same reason
[@JonathanD] you wouldn’t copy to a lun, a new one would be crated by the copy process
[Attendee1] You’ll need to sysprep.
[Attendee3] generate new ssids and all that, but yes.
[@JonathanD] Attendee2: there are better ways of doing it, in any event.
[@JonathanD] it’s primarily a DR feature
[Attendee2] well it would be killer if i could use 1 LUN for all hosts’ boot partition !
[@JonathanD] Attendee2: can’t do that, windows doesn’t support sharing disks like that.
[Attendee2] JonathanD: i didnt think i could, just for registry issues alonew
[@JonathanD] yet, anyway
[@JonathanD] (This is the switch in the chassis)
[@JonathanD] you’ll notice the interface is nearly identical
[Attendee3] So, things blinked past sorta quickly for me. To set up the LUN as a bootable disk, you used the utility on the blade?
[Attendee1] shrink the top console bar too.
[@JonathanD] can’t change it without kicking everyone out.
[@JonathanD] Attendee3: yes.
[@JonathanD] Attendee3: basically like setting boot order.
[@JonathanD] you can say “use this, then use this”
[@JonathanD] as you would with an addon raid card.
[Attendee1] That was part of the setup function in the QLogic controller attached to the chassis for the blades right?
[@JonathanD] the qlogic is the HBA, in the blade.
[@JonathanD] and theres our disks.
[Attendee1] So, diskless blades.
[Attendee3] Cool, so from this point, you just treat it like a normal disk.
[Attendee1] Now, let’s say this Blade #2 kicks the bucket.
[Attendee1] How do you fix it?
[@JonathanD] yeah, I just formatted
[@JonathanD] Attendee1: remember when I moved it from the LS21 to the HS21?
[Attendee3] can you just slide in a new blade, reassign the luns and run with it?
[@JonathanD] Attendee3: exactly.
[Attendee1] Nice, so how much to buy this technology?
[@JonathanD] a DS4700 is gonna cost you around 40k, usually
[Attendee1] And the bladecenter + blades is how much?
[@JonathanD] the expensive part there is the SAN switches.
[@JonathanD] they’re 15k. each. for 2.
[@JonathanD] which is more than the chassis itself.
[@JonathanD] so it’s not cheap 😛
[Attendee2] Attendee1: the chassis is like $5k and the blades range from $1000 – $20,000 (for that 4x dual core AMD)
[@JonathanD] right, Attendee2
[Attendee3] So, odds are good I’ll have to stick with my HP Storageworks SA1000
[@JonathanD] how does that connect, Attendee3?
[Attendee3] It was already set up when I got here, the idea was to have centralized storage for a pair of production servers, however, it never worked out that way, so now it’s just being used as a glorified external drive.
[Attendee3] It’s got four 72gig U320 drives in it.
[@JonathanD] 47K for a DS4700 with 14 500GB sata.
[@JonathanD] 7K of that was for an AIX kit for it
[@JonathanD] so 40k, yup
[@JonathanD] Now, 3400 which can get you about 3TB of storage can be had for around 15K, WITH the 3TB in it.
[@JonathanD] thats 3TB usable, after parity, hot spare, etc.
[Attendee1] Does IBM sell equipment without support contracts, or do they require support contracts?
[@JonathanD] almost anything you can get without support.
[@JonathanD] I’m pretty sure you can’t get a zSeries without it, though.
[@JonathanD] keep in mind, this is in an array that is still building 🙂
[Attendee3] Well, thanks for the demo, that was really informative. 🙂
[@JonathanD] Attendee1: what performance did you get pre-build?
[Attendee1] Like 8MB/sec or something.
[@JonathanD] so, pretty competative ehh? 😉
[@JonathanD] no problem, Attendee3
[@JonathanD] hope everyone enjoyed it.
[@JonathanD] oh, one more thing.
[@JonathanD] Attendee1: there is your perf, on just 3 drives, degraded.
[Attendee3] good demo. I’m assuming the LUN concepts will translate to other SAN devices?
[Attendee1] JonathanD: Thanks, I think I learned a bunch.
POSTED ON2007-04-11EDIT "IBM BLADECENTER GENERAL DISCUSSION" IBM BladeCenter General Discussion The following is a chat with JonathanD regarding IBM Bladecenter technology. He is a certified IBM BladeCenter expert
[Attendee1] So, how can I get one for $10/mo?
[@JonathanD] Attendee1: become an ibm business partner doing more than $100,000 a year in IBM sales, then apply for a development lease.
[Attendee2] Well, blade centers look interesting, but some of the information is moderately, er, confusing?
[@JonathanD] Anything in particular, Attendee2?
[Attendee2] Like, specifically how networking works with the backplane
[@JonathanD] I’ll summarize briefly, then you can ask questions, ok?
[@JonathanD] in a normal configuration, we’ll put 2 switch modules in a chassis.
[@JonathanD] These switches go in bays 1 and 2
[@JonathanD] regardless of the chassis
[@JonathanD] bays 1 and 2 are essentially hard wired to a network connection on each blade
[@JonathanD] each blade has to built in NICs
[@JonathanD] it’s actually a single dual port NIC, physically
[@JonathanD] first port goes to bay 1
[@JonathanD] second port goes to bay 2
[@JonathanD] so thats the baseline. Each blade connects to bay 1 and 2 at least once.
[Attendee2] So, the switch in the bay determines the speed of networking between blades, not the speed of the backplane?
[@JonathanD] Attendee2: yes. The backplane is basically just wiretraces.
[@JonathanD] theoretical limit is 10GB
[@JonathanD] however, all blades, to date, have only 1GB nics built in
[@JonathanD] now, I said at least once, because a 2 slot blade has at least the potential for 2 connections to each switch
[@JonathanD] depending on the blade, how it’s configured, and a few other things, you’ll have 1 or 2, to each
[Attendee2] So, if you wanted to add 10gb or infiniband or whatever you’d have to put in a switch for it and a module in every blade
[@JonathanD] Attendee2: essentially yes
[@JonathanD] I’m going to speak briefly on infiniband and what it can offer in a moment
[@JonathanD] just high level.
[@JonathanD] now, the enterprise chassis (just called bladecenter) has 4 IO module slots
[@JonathanD] as we discussed , 1 and 2 are dedicated to ethernet
[@JonathanD] externally, they can be fiber or copper.
[@JonathanD] the other 2 can be a wide variety of things
[@JonathanD] fiber channel, SAS, more ethernet, infiniband
[@JonathanD] in the newer H chassis, there are all-told 10 slots for different IO options.
[@JonathanD] one of these is a high speed infiniband switch.
[@JonathanD] with the infiniband switch, you can do some interesting things…
[@JonathanD] not much support exists yet for infiniband, so what we have is a special adapter that sits in the blade and talks to the infiniband switch (preferably, 2 of them for redundancy, same as ethernet)
[@JonathanD] this gives us, on top of our 2 built in GBE connections, 6 additional “virtual” connections on infiniband fabric, to each blade.
[@JonathanD] with the infiniband switch, each of these 6 can be either Fiber channel OR 10GBE
[@JonathanD] and it can vary by blade.
[@JonathanD] Attendee2: does that answer your question, and do you have any more?
[Attendee1] Do cross-blade ethernet communications exit the ethernet I/O ports or does it handle ethernet requests between blades internally?
[Attendee1] Basically, can the ethernet be unplugged external to the bladecenter and still have ethernet between the blades themselves?
[@JonathanD] Attendee1: absolutely
[@JonathanD] the switches in a blade chassis are real switches, most of them with vlan capability
[Attendee3] Why do blades talk to each other? do they all pool into one server or something? like one blade can be a file server, one an email server, one a Web server, etc? sorry for a n00b question
[@JonathanD] but yes, often folks will put a substantial infrastructure inside a single chassis
[Attendee2] er, yeah it did (sorry thought I answered)
[@JonathanD] that doesn’t need to exit the chassis at all except for the end user responses
[@JonathanD] so your web server, app server, and db server (or cluster) can live inside the chassis.
[Attendee3] So I could have like 20 blades, all doing different things, but it looks like one server to an end user? Wow.
[Attendee4] when i look at photos of the H Chassis it looks closed off from the back, so if i put an expansion module on a blade to put in a PCI card or something, where will the connection sit for that card ?
[@JonathanD] furthermore, several of the switches are capable of load balancing with no additional hardware.
[@JonathanD] Attendee4: there are fillers on the back of a BC H, you take them out to install a switch module
[@JonathanD] that switch module has external ports
[Attendee1] JonathanD: What’s the network interconnection speed between blades?
[Attendee4] perfect !
[@JonathanD] the number and type of ports vary, based on what you choose.
[@JonathanD] Attendee1: up to 40Gbit per blade, depends entirely on the switches installed.
[Attendee4] i would just love, for redudnancy, to have my PBX sit on a blade, so i would need to add my T-1 interface card to the blade
[Attendee1] JonathanD: Does it only depend on the switch, or does the blade have to support that speed too?
[@JonathanD] Attendee1: the adapter in the blade does, yes.
[Attendee3] 40Gbit/sec… wows
[@JonathanD] much like a 1Gb switch does no good if you have a 10Mbit nic
[Attendee1] JonathanD: What’s the oldest that still supports 40Gbit?
[Attendee1] (stock from IBM)
[ttender3 still has 100Mbit network…with some nodes only 10Mbit
[@JonathanD] the HS21s, almost all of them, have support for infiniband to bays 7-10 which supports that 40GBit
[Attendee1] Also, does that interconnect show as a separate network card?
[Attendee3] Infiniband = unlimited speed?
[Attendee3] i.e. “infini”band?
[@JonathanD] Attendee1: that would be an infiniband connect, which in this case you would probably configure as virtual 10GbE adapters.
[@JonathanD] you can actually exceed that 40Gbit in some cases
[@JonathanD] and as the midplane is basically just traces, thats not a hard value.
[@JonathanD] it could increase as new switching technology becomes available.
[Attendee1] The 40Gbit is per blade or overall?
[@JonathanD] Attendee1: thats the current max that can be delivered to a single blade
[@JonathanD] within the chassis, that would be point to point.
[Attendee1] Is that full duplex or half duplex speed?
[@JonathanD] which makes it excellent for vmotion, for example.
[Attendee1] (as in utilizing both send/receive to get 40Gbps, or are both @ 40Gbps) ?
[@JonathanD] thats half, so you can push 40 in both directions.
[@JonathanD] across 4 interfaces or virtual interfaces.
[@JonathanD] in short, particuarly with infiniband, you have lots of bandwidth.
[Attendee3] I used to think of Mbits like mph…10 is slow and sucky and 100 was really fast.
[Attendee3] Now we have 40Gbit!?
[Attendee3] Is this available for regular non-blade servers?
[Attendee3] the most I’ve seen is 1Gbit, honestly.
[@JonathanD] Attendee3: infiniband is, yes. I don’t know if the virtual IO tech is.
[Attendee1] So the virtual network adapter you mentioned. How is this configured?
[Attendee3] “the virtual IO tech” means what?
[Attendee1] You install a driver in Windows, and configure this on the blade center level?
[@JonathanD] Attendee1: my understanding is that it’s configured in the cards BIOS
[@JonathanD] so you can do it pre-install
[Attendee1] I see.
[@JonathanD] and much like the qlogics, once the machine is up you can install software to manage it without a reboot.
[@JonathanD] it can also be assigned from within the managemnet module, and even scripted.
[Attendee1] So you could have upto 4 of these virtual cards or can you over allocate the bandwidth, and it’ll do best effort routing?
[Attendee1] (Per blade)
[@JonathanD] it will drive to the limit of the infiniband, yes.
[@JonathanD] you can configure 10GbE interfaces, and 4GB FC interface.
[Attendee1] So other than OS limits, how many network interfaces can you create?
[Attendee1] Per blade.
[@JonathanD] includeing the 2 built in
[@JonathanD] 6, within infiniband
[Attendee3] and what pretel do you do with 6 virtual NICs?
[Attendee1] So, each blade has 2 which are connected to the external ethernet I/O ?
[Attendee3] Attendee1: sounds like it
[@JonathanD] Attendee1: to switch bays 1 and 2, yes.
[@JonathanD] the “default” ethernet.
[@JonathanD] those are part of the system board and non-removable.
[Attendee1] What’s the max interconnect speed of HS20’s ?
[@JonathanD] akin to the built in nics on an xseries.
[@JonathanD] Attendee1: depends 🙂
[Attendee3] do these suckers have PCIe or AGP support?
[@JonathanD] if you have fiber channel, you’ll be using your 1 and only expansion slot for that.
[@JonathanD] Attendee3: as they don’t have slots like that, no. But at a technical level, yes.
[Attendee1] Attendee3: It’s not designed for high-speed graphics cards.
[Attendee1] (for games).
[@JonathanD] the adapters in them are PCI-X or PCI express, in the newer
[@JonathanD] to answer Attendee4’s question
[Attendee3] JonathanD: ahh okay
[@JonathanD] you can purchase a sidecar, that takes a slot
[@JonathanD] which allows you to install 1 or 2 PCI cards.
[@JonathanD] these would be accesible at the front of the blade chassis.
[@JonathanD] Attendee4: it’s an uncommon need, only there for rare uses.
[Attendee4] i dont know if i want this nice “all-in-one” enclosure to have 2 cables running off the front of the chassis
[@JonathanD] I have to wind this up in the next few minutes.
[@JonathanD] any more questions, right now?
[Attendee1] JonathanD: Okay, so HS20, I’m still not sure what the interconnect speed is between blades.
[@JonathanD] Attendee1: ahh, sorry.
[@JonathanD] if you forgo fiber, you can put a 10GbE in modules 3 and 4
[Attendee1] Does the HS20 still do the virtual network thing too?
[@JonathanD] for 20GbE, + the 2 base.
[@JonathanD] Attendee1: afraid not, it does not have the slots for it.
[Attendee1] So modules 3 & 4 would be used internally, or what?
[@JonathanD] Attendee1: internally and externally
[@JonathanD] with 1 or more 10GbE connections to external
[Attendee1] Okay, a module services how many blades? All of them?
[@JonathanD] or has the potential to
[@JonathanD] if, for example, you have san, and one doesn’t need san
[Attendee1] So redundancy aside, you could just do one module for network, right?
[@JonathanD] you don’t have to put an adapter in it.
[@JonathanD] Attendee1: yes, and some do.
[Attendee4] JonathanD: i think i need to know more about the storage, so for your next get together we should do that !!
[Attendee1] Yes, what’s the recommended way to add storage to these things?
[Attendee3] I’m still 100% confused about virtual networking.
[@JonathanD] there was some talk of a hybrid card that would fit the existing slot in an hs20 and attach to the infiniband fabric.
[Attendee3] SCSI, I’d assume.
[@JonathanD] but there was not enough customer interest in it, unfortunatly.
[@JonathanD] Attendee3: doubtful.
[@JonathanD] Attendee1: I think we’ll have to revisit storage.
[Attendee3] IEEE 1394?
[@JonathanD] I’m gonna have to get on a customer call.
[Attendee1] JonathanD: K.
[@JonathanD] Attendee3: FC or SAS
[Attendee4] well theres no way i could afford the fibre, so i will definately be going with the SAS
[Attendee1] JonathanD: Thanks.
[Attendee3] Yes, thank you JonathanD.
[@JonathanD] no problem.
[@JonathanD] hope this was helpful for all involved.