It's nice to hear I'm on the right track. Thanks for the answers. Anthony D'Atri <anthony.datri@xxxxxxxxx>, 8 Ara 2021 Çar, 12:13 tarihinde şunu yazdı: > > I’ve had good success with this strategy, have the mons chime each other, and perhaps have OSD / other nodes against the mons too. > Chrony >> ntpd > With modern interval backoff / iburst there’s no reason to not have a robust set of peers. > > The public NTP pools rotate DNS on some period, so when the quality / jitter varies a lot among a given pool you can experience swings. So depending on the scale of one’s organization, it often makes sense to have a set of internal stratum 2 servers that servers chime against, which mesh among themselves and against both geo-local public servers and a few hand-picked quality *distant* servers. Jitter matters more than latency AIUI. > > Local stratum 1 servers are cool, though getting coax to a DC roof and an antenna mounted can be an expensive hassle. > > Success includes a variety of time sources, so that it doesn’t all go to hell when some specific server goes weird or disappears, both of which happen. Eg, if there’s a window with sky access, even in an office area, add a couple of these (or similar) to the mix, as a source for the workhorse server stratum : > > https://www.netburner.com/products/network-time-server/pk70-ex-ntp-network-time-server/# > > Not a DC grade item, or a sole solution, but the bang for the buck is unbeatable. > > > Unless things have changed in the last few years, don’t run NTP servers on VMs. Some network gear can run a server, but be careful with the load it presents and how many clients can be supported without impacting the primary roles. > > > On Dec 8, 2021, at 12:14 AM, Janne Johansson <icepic.dz@xxxxxxxxx> wrote: > > Den ons 8 dec. 2021 kl 02:35 skrev mhnx <morphinwithyou@xxxxxxxxx>: > > I've been building Ceph clusters since 2014 and the most annoying and > > worst failure is the NTP server faults and having different times on > > Ceph nodes. > > > I've fixed few clusters because of the ntp failure. > > - Sometimes NTP servers can be unavailable, > > - Sometimes NTP servers can go crazy. > > - Sometimes NTP servers can respond but systemd-timesyncd can not sync > > the time without manual help. > > > I don't want to deal with another ntp problem and because of that I've > > decided to build internal ntp servers for the cluster. > > > I'm thinking of creating 3 NTP servers on the 3 monitor nodes to get > > an internal ntp server cluster. > > I will use the internal NTP cluster for the OSD nodes and other services. > > With this way, I believe that I'll always have a stable and fast time server. > > > We do something like this. mons gather "calendar time" from outside > ntp servers, but also peer against eachother, so if/when they drift > away the mons drift away equal amounts, then all OSDs/RGWs and ceph > clients pull time from the mons who serve internal ntp based on their > idea of what time it is. > > Not using systemd, but both chronyd and ntpd allow you to set peers > for which you sync "sideways" just to keep the pace in-between hosts. > > -- > May the most significant bit of your life be positive. > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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