Hi I am currently trying to put together a proposal to upgrade our rather ancient Access Grid servers. I have looked through this list and gleaned various bits of useful information about possible configurations. I would be grateful for comments about any aspect below - apologies in advance for the length of this mail.
Background: we installed a pretty traditional room-based node about 6 years ago - a two-box HP workstation system running AG Toolkit under Linux, XAP800, Sony EVI-D100 cameras using s-video into Osprey capture cards, and using a NVidia quad-head display card. The aim is to update the servers, but keep the XAP and the existing Sony cameras for standard definition video feeds. If possible we also want to add two HD feeds for future use, from the Tandberg Precision HD cameras we also have in the room for H.323 videoconferencing (these can output simultaneously on HD-SDI, as well as the HDMI connection we use for the H.323 videoconferencing). As well as Access Grid, we want to use this infrastructure with other collaborative software such as EVO, or even to use Skype in a room-based environment. Although we have a strong preference to run things under Linux (Fedora or RHEL), we will probably want to make the new server(s) dual-boot to some flavour of Windows too so we can cope with any eventuality. We¹ve found our current hardware to be very reliable, so for starters I¹ve looked for updated versions of what we¹ve got rather than changing everything in sight. I¹m still undecided about the one box / two box question. In support of the two-box approach, I can understand the complication of the operator seeing multiple VIC instances on a one-box system, rather than just having a single instance on the display machine. Also, I do still wonder about the wisdom of expecting one box to cope with (say) capture of two HD streams and 2 SD streams, plus audio, plus quad-head graphics output and networking. That seems an awful lot of i/o (translating to CPU load). However, for use with EVO, both capture and display would need to be on the same machine (unless you signed in on two boxes, I guess). In the end of course it will probably come down to money. Your current opinions are solicited on this issue. New server(s): The HP z800 looks a pretty good spec, particularly when it comes to i/o in the form of the number and type of PCIe slots it would seem to give some options for future growth, even on a one-box solution. Also we mostly use HP for our other servers, so are generally comfortable with their support. Processors: I would prefer dual quad-core processors, but would welcome advice as to whether this would be overkill, particularly in a two-box solution. Memory: I¹m assuming that memory requirements are not particularly great, and that something like 12GB per box would be ample (memory is triple channel on the z800, so for dual processors needs to be installed in sixes, hence 6 x 2GB) Disk: Similarly the disk requirements should be modest we¹d probably keep the Linux and Windows installs on separate drives for simplicity ideally I¹d like to mirror each OS on a pair of drives. There seemed to be some references to Linux on the z800 needing SAS rather than SATA drives for any RAID config, but whether that applies to a straight RAID1 mirror I¹m not sure. At a pinch we could live dangerously and just have a single drive (146 or160GB) per OS I guess. SD video and audio capture: The initial need is to be able to support the current 4 s-video feeds, and I was looking to use the Osprey 450e if possible (though there seemed to be some doubt as to whether this was supported under Linux or VIC yet). A second best might be the Osprey 440 (normal PCI). Either should be able to do the audio capture too. HD video capture The Blackmagic cards seem to be the popular option, both for AG and EVO. The ŒDecklink Duo¹ takes two HD-SDI inputs, which would seem ideal for our system., and it seems to have a Linux driver. It isn¹t crucial for it to be supported Œright now¹ in AG Toolkit / VIC, but it would be nice to know it¹s on the horizon. Graphics card: One quad-head card supported in the z800 seems to be the Nvidia Quadro NVS 450 we¹ve previously used the similar PCI card with good results. The current PCIe model outputs on DisplayPort connectors, which we would have to convert to VGA. An alternative could be two NVidia Quadro FX580 cards, as suggested here: http://www.arcs.org.au/index.php/tturnkey-video-collaboration/318-room-based -turnkey-vc-system but I am not sure what the benefits would be compared with the single card. There¹s probably something else obvious I¹ve missed but this is long enough already. Thanks in advance for any comments Phil Stanford National Oceanography Centre Southampton, UK
