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Re: Super-Newbie question

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  • mbanditt
    ... with USB support for $39 USD. It only supports 200W at 115V, and that only for a few minutes, but it should suffice for an NSLU2 and few drives. Great.
    Message 1 of 11 , Oct 2, 2005
      --- In nslu2-general@yahoogroups.com, "Mike Westerhof" <mwester@d...>
      wrote:
      > A local chain here (Compusa) is selling an APC UPS (shoebox size)
      with USB support for $39 USD. It only supports 200W at 115V, and that
      only for a few minutes, but it should suffice for an NSLU2 and few
      drives.

      Great. These really seem usable and, what's even better, there seem to
      be at least two driver projects that work with APC: NUT and apcupsd.
      The latter is also in debian repositories, so that should be eady to
      install on an OpenDebianSlug.

      Unfortunately, here in Switzerland the APC ES series in not available.
      But I could get one in Germany and use a power adapter. The price is,
      however, close to 100$ for the cheapest one.

      > In any case, the software is the NUT
      (http://www.networkupstools.org/) software - it seems architecturally
      well-suited to the slug. It supports both USB and serial UPS devices.
      On the NSLU2 the serial devices will require a USB->serial adaptor.
      Since those are almost as much $$ as the UPS, I can't see many folks
      going that route, but I happen to have a couple of old serial units
      lying about, so that's what I'm testing on right now. The software
      builds easily; and once I figured out that the USB/serial driver for
      the adaptor I'm using requires a patch, it got a lot easier to test!
      :-) It's fairly simple to respond to a "low battery" event by
      initiating a shutdown, which is all I've tested and got working so
      far.
      >

      As mentioned above, have also a look at the apcupsd project.

      > The big challenges I see are these:
      >
      > a) Lack of USB ports. Nothing to be done about that for the normal
      user, I'm afraid. A USB port is required to interface to the UPS,
      which cuts in half the amount of storage the slug can handle. There
      are some who have found USB hubs that work with the slug, but this is
      probably the biggest problem I see in making the software useful. If
      support for hubs can be added into Unslung 6, that would be great!
      Otherwise, if there were some way to characterize those hubs that DO
      work with the slug, there would at least be a repeatable solution for
      those who wish dual drives AND an interface to a UPS.
      >

      Hmm, I'd try a hub. At least with OpenSlug or OpenDebianSlug the
      chances should be good that it will work.

      > b) Lack of automatic power-on. The traditional way to handle a UPS
      low-battery alert is for the equipment to perform an orderly shutdown,
      then signal the UPS to turn off. Doing this leaves the equipment in
      the "on" state, the UPS in the "off" state, and since the overwhelming
      majority of UPSs will restore power to the load side when the line
      power is restored, results in the protected equipment automatically
      powering up when the power returns. The NSLU2, however, doesn't do
      this (unless, of course, hardware modifications are performed -- see
      the howto in the wiki). So it will simply wait for someone to notice
      that it's not running, and push the little "power" button. This could
      be a real bummer for some, or just no big deal for others. I'd
      appreciate feedback from folks to guage just how big a problem this
      is.
      >

      That's true, but I guess I'd go for the power-on hardware mod. It
      seems to be quite easy.

      > I'd personally like to see the resolution to item "b" handled a
      little differently. My situation may be unusual, though. I'd like the
      NSLU2 to go "quiet" after only a few minutes on battery, thus
      preserving most of my UPS for the rest of the gear it supports - my
      router/firewall and my VOIP. While it might be nice to have my NSLU2
      ride out a power failure, it would be even nicer to make sure I have
      telephone service!
      >
      > I'm not sure how to implement a technique such as this, but this is
      what I'd like to be able to do:
      > - Upon powerfail, notify interested systems on the network in the
      normal "NUT" fashion.
      > - After some period of time (5 minutes), put the NSLU2 to "sleep"
      > + shutdown all daemons except the NUT processes
      > + umount all drives (hopefully permitting them to spin-down and
      save power)
      > + sleep until the UPS either shuts off power, or signals return
      of line power
      > + if line power remains up for some short period (2 minutes),
      begin reboot
      >
      > I suspect this will be much harder than it sounds, especially the
      umount of the drives (I doubt that's even possible). Hopefully they
      can be put in a mode where they will be read-only (ensuring data
      integrity), and where they will be "quiet" so they can spin down. Of
      course it would also be nice if the "spin-down" features were
      implemented in the kernel so the drives could be ordered to do so, but
      if wishes were horses...

      Nice idea, but not very easy. So you would do a killall to all
      processes, then make a ramdisk, cp a minisystem into the ram and
      chroot into it. Then it might be possible to umount all drives, and
      afterwards use scsi-spin to manually spin them down ???

      Maybe it's easier to really shutdown...

      >
      > Anyway, that's the idea - feedback is gratefully accepted,
      especially if what I'm outlining is totally wrong!
      >
      > Thanks,
      > wester
      >

      Thanks for your suggestions. I guess, I get one of these. (Although,
      to be honest, power outages are very rare here; maybe once or twice a
      year, and mostly for just a minute or two...)

      Cheers,

      Michael
    • tollewerbung
      ... can t do bootp) ... Ghost to backup my work laptop and my wife s business laptops across the network. When working on a system I don t need a CD drive or
      Message 2 of 11 , Sep 6, 2007
        --- In nslu2-general@yahoogroups.com, "Mike Westerhof" <mwester@...>
        wrote:
        >
        > - DHCP services with bootp (replaces DHCP from my firewall which
        can't do bootp)
        > + bootp allows me to boot systems from the network. I use Norton
        Ghost to backup my work laptop and my wife's business laptops across
        the network. When working on a system I don't need a CD drive or a
        floppy; I can boot up IBM's disktest, Dell's diagnostics, or an
        assortment of other tools right from the network.

        Hello Mike,

        could you please give me some insight what you did to enable bootp
        (netboot protocol) on your NSLU2? Is there a bootp daemon running?
        Would it be possible to get this also on a NSLU2 which runs OpenSlug
        3.10b (instead of Unslung)? Did you compile the daemon yourself or are
        there packages around which I have not yet found?

        I plan to make backups of my Macbook (OS X 10.4.10) which is known to
        be able to boot from e.g. Mac OS X Server via bootp (netboot
        protocol). If it is possible to put a backup image on a NSLU2-HDD and
        boot the Macbook from there, it would be fantastic.

        Thanks for your hints!

        Best regards,
        AlphaOmega
      • Mike (mwester)
        ... In the original incarnation, I used a variety of separate bits of code, but now everything can be done by a single package - dnsmasq. The latest versions
        Message 3 of 11 , Sep 8, 2007
          > could you please give me some insight what you did to enable bootp
          > (netboot protocol) on your NSLU2? Is there a bootp daemon running?

          In the original incarnation, I used a variety of separate bits of code, but
          now everything can be done by a single package - dnsmasq. The latest
          versions even include support for the tftpd protocol.

          > Would it be possible to get this also on a NSLU2 which runs OpenSlug
          > 3.10b (instead of Unslung)?

          Dnsmasq is available in both the Unslung as well as the SlugOS feeds.

          Mike (mwester)
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