Bicster

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Everything posted by Bicster

  1. My 24-port Dell PowerConnect 2724 arrived yesterday. I paid about $290 after tax/shipping. My first impression was that the thing is heavy for its size. It comes with 19" rackmount brackets and wall-mount brackets. The switch is substantially narrower than 19" -- maybe 14-15". It has an integrated 100-240V power supply and one 4cm cooling fan. The 8 and 16-port models lack the fan. The 8-port model does not support Jumbo Frames. Inside the unit, the processor and switch chips all have hefty heatsinks. I opted to disconnect the cooling fan since the noise was intrusive and the unit doesn't seem to especially need the active cooling. It took me a while to get the managed features to work. When the switch is first powered up, it behaves like a dumb switch without any management features. There is a recessed button on the front of the unit that can be poked with the end of a paper clip. Pressing that button is supposed to enable the management features. Once enabled, the switch stays in managed mode until disabled again (even if the switch is powered off.) Also, switching between managed and unmanaged modes wipes out the configuration. The manual mentions a "Ready" LED which is supposed to indicate that the switch has successfully completed it's POST procedures. Unfortunately the switch has no such LED. Instead, it appears that Dell opted to make the "Managed Mode" LED blink until the POST is completed. The switch takes several minutes to complete the POST, but appears to switch traffic almost immediately after power is applied. Changing the IP address of the switch requies a reboot, as does enablng jumbo frames. Upgrading the firmware requires a TFTP server. It is a painless but slow process. My switch shipped with pre-release firmware, which I upgraded to the "initial release" firmware obtained via the Dell website. I had to manually reset the switch via the web management GUI after downloading new firmware via TFTP. The flash process then took 4-5 minutes. Overall, the process might have taken 10 minutes. The VLAN support works well. I haven't tested jumbo frames yet -- setting my e1000's MTU to 9000 caused my Linux server to reboot after a few seconds. Port mirroring is supported. A mirrored port can mirror all ports, or just one, with the option of Rx or Tx mirroring only. The web management GUI is slow, but acceptable. It would be nice to have telnet or serial administration as well. There is no SNMP support, which is a disappointment, but I knew that before ordering. The web GUI does have ample statistics available for every port. It can even auto-refresh the information. The 2724 went bonkers when I connected two of its ports together. That disappointed me. I have a few cheap switches that are immune to that problem. For me, the switch has one deal-breaker so far: there is no way to back up or restore the configuration. That means that complicated configurations must be documented carefully by hand, and in the event the switch fails and needs replacing, it's going to take a long time to get the new one fully configured. That's all I can think of for the moment!
  2. Bicster

    SSD's = Defrag is a thing of the past?

    Fragmentation will still slow down an SSD, but it would be a lot harder to notice / measure. By way of example, it's faster to request one 64KB block of data than eight 8KB blocks. That said, I doubt I'd bother to defrag any SSD's I own.
  3. Bicster

    Sandisk 32GB 2.5" SATA SSD drive...

    Oops, that is correct. A handful of CF cards support DMA modes 1, 2 or 4. The new cards are the first that support UDMA. Sandisk Extreme IV uses UDMA 4. Unfortunately the cheaper 120X CF cards suck at non-sequential small writes. Cardbus is a derivative of PCI, so Cardbus to CF adapters would need to have a PCI/IDE controller chip. That Delkin card is pretty cool. I forget who makes it. Delkin just slaps their name on it. Most of the cheaper adapters are PCMCIA, not Cardbus. I'm not sure if they are completely passive but they are definitely much simpler.
  4. Bicster

    Sandisk 32GB 2.5" SATA SSD drive...

    CF to IDE adapters are completely passive devices. CF cards are native IDE in the first place. (They also support other modes, but that's of no consequence to us.) The adapters just give you a way to plug them in. There are no bridge chips for CF-IDE. CF-SATA would use the same bridge chip (i.e., Marvell) that early-generation SATA drives used. There is little to no performance loss with such a bridge chip. The catch is that nearly all existing CF cards only support PIO transfers, and that is a huge bottleneck. The other problem is that Flash has always been a slow technology, but it's been gaining speed quickly. That's why the new UDMA cards are a big deal. They eliminate the PIO bottleneck, use multi-channel flash controllers, write buffers, etc., and should outperform magnetic discs on just about any real workload (not on sequential transfer rate tests).
  5. Bicster

    Sandisk 32GB 2.5" SATA SSD drive...

    You can get fast SSDs already - Lexar and Sandisk have already launched CF cards that support UDMA. Sandisk's is shipping; Lexar's is a paper launch. The speeds are very good. Lexar is claiming sustained writes of 45MB/sec and a launch capacity of 8GB. The Sandisk Extreme IV 8GB CF card claims 40MB/sec read/write. I found it in stock for $229 and there is even a $20 rebate being offered, for $209 delivered. It's nowhere near the $/GB of the SSDs they just announced, but you can actually get your hands on one. The beauty of the UDMA CF cards is that you can stick them in dirt cheap CF/IDE adapters and use them to their full potential. I've even seen a CF/SATA adapter for sale. I wish I could replace the agonizing 1.8" HDD in my Sony laptop with a CF card!
  6. I'm ready to buy drives for home RAID use. I'm considering the T7K500 320GB and the WD3200AAKS. I know the AAKS is a new series (and still hard to find), but it would seem that overall WD is one of the more reliable brands. The reliability survey doesn't have the T7K500 in it. Any anecdotal evidence on how reliable the T7K500's are would be appreciated. Thanks!
  7. Has anyone been using a significant number of either drive in a production system, say, a SAN or NAS?
  8. Bicster

    Sandisk 32GB 2.5" SATA SSD drive...

    IIRC the write speed was 42 or 45 MB/sec. Not bad at all! Sandisk has a PDF spec sheet with all the details. I just have one question: When can I buy one?
  9. On the Athlon 64/Opteron platform it has nothing at all to do with the chipset. The memory controller is in the processor. If you look at the processor spec sheets, they state what type of memory is supported. Registered memory support requires that the BIOS be able to properly program the memory controller for it. Likewise, enabling ECC support. I have seen extremely few systems that would not accept ECC memory. It does not take anything special to support ECC as regular memory. ECC DIMMs just have an extra 8 bits of memory width, typically one extra memory chip per side of the DIMM unless it's a very unusual DIMM.
  10. Goo-Gone usually works pretty well. So far I've not seen it damage anything. Rubbing alcohol also helps remove many adhesives. It evaporates quickly and doesn't leave any residue.
  11. Socket 939 does support ECC, but I did not think it was possible to use registered/buffered memory with it. Interesting. As far as the ECC goes, the memory won't be used in ECC mode unless you can somehow enable that in the BIOS.
  12. Bicster

    Raid without a Raid controller?

    You can do that, but you won't be able to boot from disk 1 if disk 0 fails. Have you considered simply using the extra disk for backups? That way you're also covered in the event that you accidentally delete some files, etc. Performance depends on implementation, but in theory RAID 1 offers faster reads and slower writes. That is FUD. It was true in the past ... but many of today's PC's have far more I/O bandwidth, memory bandwidth, and CPU power than most RAID controllers could hope for. I'm not knocking hardware RAID -- but it's important to keep things in proper perspective.
  13. Bicster

    Rack Mount SATA Case

    Coraid ( http://www.coraid.com/ ) makes a rack shelf that lets you plug SATA drives directly into a gigabit network, using ATA over Ethernet. It's said to be very fast and flexible, but I think they only support Linux at the moment.
  14. Bicster

    Boot network image? iSCSI?

    Personally I'd rather see ATAoE (ATA over Ethernet) than iSCSI. iSCSI is complated and slow. ATAoE is simple and elegant, and doesn't need a network stack. Booting from it should be a piece of cake using something like Etherboot as a code base. And Etherboot can be embedded into the BIOS... Unfortunately, ATAoE is new, and currently supported by only one vendor (Coraid). Linux has an ATAoE initiator but there is currently no free ATAoE target. It would be very easy to make one, though! If someone extended Etherboot to provide BIOS disk services, then it would still take a Windows storage driver. That driver would have to provide both the Ethernet support and ATA support. (You'd use another NIC for your LAN.) Just thinking outside my ass...
  15. Give it at least 5 minutes after powering it up. The managed mode LED will stop blinking at some point. You should be able to get in soon after that. You did enable the managed mode, didn't you?
  16. Bicster

    Video Surveillance with pc.

    Another thing to consider is wiring. You can get inexpensive baluns that will let you run video & power over cat5 cable to your cameras -- much easier to wire than RG6. Most "real" surveillance cameras use AC power supplies too. That accomplishes 2 things: 1) much lower voltage loss over long runs of power cable, and 2) keeps the video refresh sync'd to the powerline somehow. You should be able to get a nice B&W AC powered camera for $60-80 from one of the many online CCTV shops. They use interchangable lenses, too. Remember the tradeoffs between wide apertures (excellent light sensitivity) and medium ones (good depth of field). One of my cameras has an F/1.0 lens, and it has basically no depth of field. It's useless for generall scene surveillance.
  17. Bicster

    Video Surveillance with pc.

    There are some cheap (under $100) bttv cards that can capture 4 channels of video in a single PCI slot. They won't capture all channels at once @ 30fps, but you can still get more than adequate frame rates for security. I wish I could comment on the ATI cards, but I've never touched one. (And I use mostly Linux anyway.)
  18. Bicster

    Video Surveillance with pc.

    Network cameras tend to be expensive for home users -- good ones anyway. Also, beware that most network cameras use CMOS sensors that will likely fry in direct sunlight. For outdoor use you should stick with CCD sensors. As far as "night vision" goes, any B&W surveillance camera can do night vision if you have a source of infrared illumination. IR illuminators are available all over the cost spectrum. B&W cameras are also more light sensitive to begin with than color. There are even color/B&W cameras that do night vision by switching to B&W at night and cutting out the IR filter.
  19. Bicster

    Video Surveillance with pc.

    ZoneMinder ( http://www.zoneminder.com/ ) is an astounding piece of freeware that runs on Linux. It does require a dedicated server, but a cheap one will do, and the extremely cheap bttv capture boards work with it. The front end is web-based and it is very powerful! It captures all the time, but doesn't save video unless motion is detected. Then it creates video streams, lets you do frame by frame analysis, and so on. And I'm just scratching the surface...
  20. I want to upgrade my workstation. Right now I have a fanless AGP Quadro board with dual DVI out. I have two DVI monitors on my desk. All the new motherboards have dispensed with AGP in favor of PCI-e. Although there are several dual-DVI PCI-e boards on the market, they are expensive, and they are not fanless. I don't give a whit about 3D performance and I hate the noise and unreliability of typical video card fans. So I would like to get an SLI-enabled motherboard and run two cheap PCI-e video cards in it, but without SLI. I assume this can be done, but assumptions are dangerous. Does anyone know for sure?
  21. Bicster

    Boot network image? iSCSI?

    It's only hard because Microsoft doesn't support it. I've been booting diskless Linux boxes for years using Etherboot and PXE. I've even booted some diskless workstations into DOS.
  22. Bicster

    Boot network image? iSCSI?

    Wow, I'd really like to play with that too. I've wanted diskless WinXP boxen for quite some time.
  23. Intel and AMD are adding hardware virtualization instructions to their CPU's next year. That means that someone will write a wedge layer (or patch Xen) and boot Mac OS X on commodity x86 hardware ... probably running in parallel with Linux or BSD, and without much of a performance hit. Sign me up
  24. Bicster

    DVDDecrypter is Dead

    Those bastards.
  25. Bicster

    Hi Eugene, using HTTP compression

    What I am doing is essentially set up without much regard for performance. I use it for sandboxes, testing, and security. Although I guess it might be possible to use it as a performance tweak, it could easily end up being a masochistic exercise in futility. Xen works very well but there is overhead, about 5-10%, plus additional latency. It works a lot better than UML. If you haven't played with it, download the Xen 2.0.6 Demo CD. It's a bootable live demo with a high coolness factor. My Apache2 reverse proxy is primarily there to allow all my virtualized machines to use name-based virtual hosting on a single IP address.