Re: [time-nuts] Best OS for small time server
Quoth Hal Murray at 2008-02-24 08:45... If I was going to run a NTP server out of flash, I'd put the log files in RAM and back them up occasionally (ballpark, 1 hour) to flash. Do you mean a RAM disc? And how about using NFS for backing up the logs? I may still use an old laptop hard disc that I have kicking around rather than struggling with the Flash route. I've never used OpenBSD before nor have I tried running a system of Flash, so I see a regular hard disc install as the path of least resistance. Probably stick the disc in a desktop machine, do the install, then transfer to the SBC and carry on via telnet or SSH. (I don't have a keyboard adapter for the SBC, nor have I built the serial adapters yet.) Doing it with Flash can be an option when I have some familiarity with installing the OS (only really familiar with Linux when it comes to weird installations). Cheers M -- Matthew Smith Smiffytech - Technology Consulting Web Application Development Business: http://www.smiffytech.com/ Personal: http://www.smiffysplace.com/ LinkedIn: http://www.linkedin.com/in/smiffy ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Best OS for small time server
On Sat, Feb 23, 2008 at 2:29 PM, Matthew Smith [EMAIL PROTECTED] wrote: I may still use an old laptop hard disc that I have kicking around rather than struggling with the Flash route. I've never used OpenBSD before nor have I tried running a system of Flash, so I see a regular hard disc install as the path of least resistance. Probably stick the disc in a desktop machine, do the install, then transfer to the SBC and carry on via telnet or SSH. (I don't have a keyboard adapter for the SBC, nor have I built the serial adapters yet.) I can think of two options for minimizing log writes to disk: either move the contents of /var/log to /var/log.proto and mount a ramdisk on /var/log swap /var/log mfs rw,-s=65000,nodev,noatime,nosuid,-P=/var/log.proto 0 0 or use syslogd's circular memory buffer and pull the logs every so often with syslogc the -P flag allows you to prepopulate a ramdisk with contents from an prototype directory. In this case you'd have all of the logfiles, but empty, otherwise syslogd will be unable to log since it doesn't create logfiles, it just appends them. Don't worry about swap - that's just a dummy placeholder to make the call to mount_mfs line up properly. CK -- GDB has a 'break' feature; why doesn't it have 'fix' too? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Best OS for small time server
Hi Rob I live in Texas, so I have something more than a passing familiarity with oppressive heat. In essence, every watt imported into my den has to be forcibly removed 9 months of the year, if not more. Yup - sounds like here, probably just shifted by six months. ... I picked up a Linksys NSLU2 network storage widget and hacked into it. It runs a minimal Linux system on a very low power ARM processor, and uses USB attach disk storage. Hmm - interesting. I know of these 'slugs' being used as the heart of 1-Wire (R) weather systems. Think there is a way of fitting a serial port, with a little hardware hacking, but will have to check on that. ...But I thought you'd fine the flash disk results interesting. And was my concern, but the atime thing mentioned in other posts may be a way around it. Beyond this, Dave Mills, the author of NTP has a great paper on high resolution timekeeping in Unix kernels. It's a bit dated, circa 1994, but it might be worth a read. I thank you - I'll have a look at this. Cheers M -- Matthew Smith Smiffytech - Technology Consulting Web Application Development Business: http://www.smiffytech.com/ Personal: http://www.smiffysplace.com/ LinkedIn: http://www.linkedin.com/in/smiffy ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Best OS for small time server
Quoth Chris Kuethe at 2008-02-22 11:45... i usually mount my timeserver's filesystems async,noatime - the only thing i'm going to lose is logs, and those aren't terribly valuable. If this means I can run of Compact Flash without running into the (very) finite rewrite limit, this would be good. Cheers M -- Matthew Smith Smiffytech - Technology Consulting Web Application Development Business: http://www.smiffytech.com/ Personal: http://www.smiffysplace.com/ LinkedIn: http://www.linkedin.com/in/smiffy ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Best OS for small time server
On Fri, Feb 22, 2008 at 12:57 AM, Matthew Smith [EMAIL PROTECTED] wrote: Quoth Chris Kuethe at 2008-02-22 11:45... i usually mount my timeserver's filesystems async,noatime - the only thing i'm going to lose is logs, and those aren't terribly valuable. If this means I can run of Compact Flash without running into the (very) finite rewrite limit, this would be good. I've run quite a number of firewalls built around SBCs, running off CF... they've been in production over 5yrs without a problem. Plus, I don't think CF is quite as fragile as it used to be. CK -- GDB has a 'break' feature; why doesn't it have 'fix' too? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Best OS for small time server
Quoth Jason Rabel at 2008-02-21 14:14... ... FreeBSD will support a PPS signal natively. If you have a hard drive you could just run a plain install, if you want to run off a CompactFlash module then I would suggest building a NanoBSD image. It took me a few tries to get it right but I'm very happy with the performance. I was going to use an old laptop disc for this as I have absolutely no experience with 'small' Un*x implementations - like what happens to /swap, etc. However, I would prefer a system that uses as little power as possible and has no moving parts, so should probably investigate the CompactFlash option - I'll Google for NanoBSD. Just had a quick look on eBay - seems like I can get a CF to 44 pin laptop IDE adapter for $AUD 12 delivered and a 1Gb CF card for $AUD 30 delivered (I'm assuming that 1Gb should be more than adequate for a system like this). So, not expensive, probably worth a go. ntpns currently only supports the Oncore dcf77 receivers, so its not for everyone. I have it running on my net4501 w/Oncore UT+ and it has been happily humming away. I've got a couple of Oncores in my desk somewhere, but they are just the GT model. I think that the Trimble ACE II has better PPS accuracy than these, although I'd have to check. Besides a time server what other features are you looking for? If you mean what else do I want this box to do, haven't really decided. As I have the components kicking around, I thought that it would be nice to run my own Stratum I time server, rather than having to rely on the local Stratum II pool (may keep this for sanity checking though). As our power is not all that reliable here (on the end of a LONG Single Wire, Earth Return 19kV line), I wanted something that could run off a trickle-charged sealed lead acid battery, rather than further burdening my main UPS - which only runs for an hour anyway. I have been giving some thought to having an external USB hard disc on the thing for my server backups. Currently, I have a Sun Blade 100 doing this job - uses a bit more power than is really necessary. (And adds to the heat problem in my office in the cruel South Australian Summer. But keeps it nice and warm in Winter.) I've thought of building some radio-controlled (434MHz Aussie ISM band) slave clocks, but don't know if I'll use this as the master, or use a separate receiver. More on that another time - I have some ideas for some rather 'different' clocks that I'd like to build. Cheers M -- Matthew Smith Smiffytech - Technology Consulting Web Application Development Business: http://www.smiffytech.com/ Personal: http://www.smiffysplace.com/ LinkedIn: http://www.linkedin.com/in/smiffy ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Best OS for small time server
Matthew, I live in Texas, so I have something more than a passing familiarity with oppressive heat. In essence, every watt imported into my den has to be forcibly removed 9 months of the year, if not more. I maintain a low stratum NTP server at home, sadly not stratum 1 (yet!) on a small machine that runs 24x7. In addition to NTP duty, it hosts some network filesystems, DHCP, periodic batch jobs via cron (rsync, etc...), and provides a ssh landing pad. I used to run this on an old SPARC IPX, later a Pentium-1, followed by a Pentium Pro PC, etc... The heat noise started getting to me. I picked up a Linksys NSLU2 network storage widget and hacked into it. It runs a minimal Linux system on a very low power ARM processor, and uses USB attach disk storage. I successfully ran these network services sans network filesystems on a 1Gb USB memory stick for about 8 months. It was completely silent, and the total power draw was roughly 5 watts. The problem I ran into is that Linux implements a POSIX compliant filesystem. Even taking steps to eliminate swap, the never ending filesystem metadata updates burned up my little flash drive in less than a year. BSD will not escape this problem. It will be true on any system that records file access/modify timestamps. There might be a way to turn them off, or you might be able to mount certain partitions read-only. I've since gone back to a full size (~90mm) USB attach disk. It takes a bit more power, and makes a bit more noise, but it gets the job done, and should have a 5 year life span. I don't think a NSLU2 could be adapted for stratum 1 NTP use without some serious hacking, as a serial port would be a USB dongle. But I thought you'd fine the flash disk results interesting. Beyond this, Dave Mills, the author of NTP has a great paper on high resolution timekeeping in Unix kernels. It's a bit dated, circa 1994, but it might be worth a read. I'm not sure if Linux follows his guidelines or not. I believe Solaris and several of the BSD's do. http://www.eecis.udel.edu/~mills/papers.html Rob On Feb 21, 2008, at 4:36 PM, Matthew Smith wrote: Quoth Jason Rabel at 2008-02-21 14:14... ... FreeBSD will support a PPS signal natively. If you have a hard drive you could just run a plain install, if you want to run off a CompactFlash module then I would suggest building a NanoBSD image. It took me a few tries to get it right but I'm very happy with the performance. I was going to use an old laptop disc for this as I have absolutely no experience with 'small' Un*x implementations - like what happens to /swap, etc. However, I would prefer a system that uses as little power as possible and has no moving parts, so should probably investigate the CompactFlash option - I'll Google for NanoBSD. Just had a quick look on eBay - seems like I can get a CF to 44 pin laptop IDE adapter for $AUD 12 delivered and a 1Gb CF card for $AUD 30 delivered (I'm assuming that 1Gb should be more than adequate for a system like this). So, not expensive, probably worth a go. ntpns currently only supports the Oncore dcf77 receivers, so its not for everyone. I have it running on my net4501 w/Oncore UT+ and it has been happily humming away. I've got a couple of Oncores in my desk somewhere, but they are just the GT model. I think that the Trimble ACE II has better PPS accuracy than these, although I'd have to check. Besides a time server what other features are you looking for? If you mean what else do I want this box to do, haven't really decided. As I have the components kicking around, I thought that it would be nice to run my own Stratum I time server, rather than having to rely on the local Stratum II pool (may keep this for sanity checking though). As our power is not all that reliable here (on the end of a LONG Single Wire, Earth Return 19kV line), I wanted something that could run off a trickle-charged sealed lead acid battery, rather than further burdening my main UPS - which only runs for an hour anyway. I have been giving some thought to having an external USB hard disc on the thing for my server backups. Currently, I have a Sun Blade 100 doing this job - uses a bit more power than is really necessary. (And adds to the heat problem in my office in the cruel South Australian Summer. But keeps it nice and warm in Winter.) I've thought of building some radio-controlled (434MHz Aussie ISM band) slave clocks, but don't know if I'll use this as the master, or use a separate receiver. More on that another time - I have some ideas for some rather 'different' clocks that I'd like to build. Cheers M -- Matthew Smith Smiffytech - Technology Consulting Web Application Development Business: http://www.smiffytech.com/ Personal: http://www.smiffysplace.com/ LinkedIn: http://www.linkedin.com/in/smiffy
Re: [time-nuts] Best OS for small time server
In message: [EMAIL PROTECTED] Robert Vassar [EMAIL PROTECTED] writes: : I successfully ran these network services sans network filesystems on : a 1Gb USB memory stick for about 8 months. It was completely silent, : and the total power draw was roughly 5 watts. The problem I ran into : is that Linux implements a POSIX compliant filesystem. Even taking : steps to eliminate swap, the never ending filesystem metadata updates : burned up my little flash drive in less than a year. BSD will not : escape this problem. It will be true on any system that records file : access/modify timestamps. There might be a way to turn them off, or : you might be able to mount certain partitions read-only. mount -o noatime will fix this on BSD. I've deployed 32MB CF with this in the field that have survived for 6 years now. I did have two partitions: the binaries were in a read only file system. The modified data went into a separate partition mounted -o noatime. I thought linux also had a noatime option... Warner ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Best OS for small time server
On Thu, Feb 21, 2008 at 4:49 PM, Didier Juges [EMAIL PROTECTED] wrote: In the mean time, -o noatime is a nice option when available, I suspect it will improve performance even on systems with fast hard drives. Setting noatime requires a reboot (or a remount). remount is cheap and easy linux: mount -o remount,noatime... bsd: mount -uo noatime ... i usually mount my timeserver's filesystems async,noatime - the only thing i'm going to lose is logs, and those aren't terribly valuable. CK -- GDB has a 'break' feature; why doesn't it have 'fix' too? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Best OS for small time server
Atime implementation on Linux (and I suspect maybe other *nix as well) was, well, bad, maybe still is. Even if files are in the cache, the OS will update atime on the disk. There were talks of fixing that on Linux a while back, I am not sure if it has been done. I lost track. In the mean time, -o noatime is a nice option when available, I suspect it will improve performance even on systems with fast hard drives. Setting noatime requires a reboot (or a remount). Didier KO4BB -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of M. Warner Losh Sent: Thursday, February 21, 2008 5:39 PM To: time-nuts@febo.com; [EMAIL PROTECTED] Subject: Re: [time-nuts] Best OS for small time server mount -o noatime will fix this on BSD. I've deployed 32MB CF with this in the field that have survived for 6 years now. I did have two partitions: the binaries were in a read only file system. The modified data went into a separate partition mounted -o noatime. I thought linux also had a noatime option... Warner No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.20.9 - Release Date: 2/20/2008 12:00 AM ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Best OS for small time server
Hi Folks I am about to put together a little time server for my office network based on a Trimble ACE II GPS unit and a single-board computer with a Pentium MMX CPU. Assuming that the main function of this computer is to run ntpd with PPS, what is the current best choice of OS - also taking into consideration the fact that it is a computer with limited resources in todays terms. Linux or one of the BSDs? Cheers M -- Matthew Smith Smiffytech - Technology Consulting Web Application Development Business: http://www.smiffytech.com/ Personal: http://www.smiffysplace.com/ LinkedIn: http://www.linkedin.com/in/smiffy ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Best OS for small time server
On Wed, Feb 20, 2008 at 1:43 PM, Matthew Smith [EMAIL PROTECTED] wrote: Hi Folks I am about to put together a little time server for my office network based on a Trimble ACE II GPS unit and a single-board computer with a Pentium MMX CPU. Assuming that the main function of this computer is to run ntpd with PPS, what is the current best choice of OS - also taking into consideration the fact that it is a computer with limited resources in todays terms. Linux or one of the BSDs? I've built a few little time servers based on OpenBSD. The kernel can grab a timestamp of the 1PPS signal and can extract time data from the NMEA stream and feed those to ntpd. My home time server is a gps18/lvc hanging off serial port 2 on a soekris net4801. it's adequate, considering i have to use home powerline network to bring net to the soekris. I'm sure there are are much higher precision installations, but this was quick, easy, and basically good enough. PHK's ntpns looks neat too... CK -- GDB has a 'break' feature; why doesn't it have 'fix' too? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Best OS for small time server
I am about to put together a little time server for my office network based on a Trimble ACE II GPS unit and a single-board computer with a Pentium MMX CPU. Assuming that the main function of this computer is to run ntpd with PPS, what is the current best choice of OS - also taking into consideration the fact that it is a computer with limited resources in todays terms. Linux or one of the BSDs? I've built a few little time servers based on OpenBSD. The kernel can grab a timestamp of the 1PPS signal and can extract time data from the NMEA stream and feed those to ntpd. My home time server is a gps18/lvc hanging off serial port 2 on a soekris net4801. it's adequate, considering i have to use home powerline network to bring net to the soekris. I'm sure there are are much higher precision installations, but this was quick, easy, and basically good enough. PHK's ntpns looks neat too... Linux would require some work to get a PPS signal to work... Either using a custom patched kernel, shmpps, or gpsd (the last two are probably the easiest to implement methods). Also while I'm sure there are CompactFlash type distro's, I'm not familiar with any. FreeBSD will support a PPS signal natively. If you have a hard drive you could just run a plain install, if you want to run off a CompactFlash module then I would suggest building a NanoBSD image. It took me a few tries to get it right but I'm very happy with the performance. ntpns currently only supports the Oncore dcf77 receivers, so its not for everyone. I have it running on my net4501 w/Oncore UT+ and it has been happily humming away. Besides a time server what other features are you looking for? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
