DHCP restart with bulk lease data

[Sten Carlsen]

> On 29 Oct 2019, at 13.49, Surya Teja <suryateja042 at gmail.com> wrote:
> 
> Could there be issues with file permissions?
> My guess is that the temporary file written can not be renamed because dhcpd does not have write permissions?   ------>
> Hi Sten, I don't think it is with permission because after few minutes dhcpd is restarting and granting lease, the issue is it is taking long time,

I was thinking that since it leaves the .<time> file present, it may have problems doing the file operations. 
I did some experimenting, whatever way I make the files write protected, dhcpd manages to change them back. The only thing I did not test is SELinux.

> In the isc dhcp forum I observed few options like  dont-use-fsync but it also suggest not recommended until thorough understanding OS 
> I have installed the dhcpd on centos7, does any one have used this option? Any experience with it would be much helpful for me     
> 
> Thanks in advance
> 
> On Tue, Oct 29, 2019 at 6:12 PM Surya Teja <suryateja042 at gmail.com <mailto:suryateja042 at gmail.com>> wrote:
> you're doing something wrong. With a decent disk subsystem this is expected to take a few *seconds* (5 - 10 seconds would be my estimate ) ---->
> Hi  sthaug I don't see any disk subsystem issues, may be I am missing the cases, can you please suggest the areas or commands to cross check if possible?
> 
> 
> Thanks Teja
> 
> On Tue, Oct 29, 2019 at 5:13 PM Sten Carlsen <stenc at s-carlsen.dk <mailto:stenc at s-carlsen.dk>> wrote:
> 
> 
> > On 29 Oct 2019, at 11.20, sthaug at nethelp.no <mailto:sthaug at nethelp.no> wrote:
> > 
> >> The main thing I am facing the issue is when the data is too high like
> >> 50-60k leases in the file, the dhcpd service restart is taking more time
> >> (nearly 5-6 minutes) some times nearly 10-11 mins
> > 
> > If a dhcpd restart with 50 - 60k leases takes 5-6 minutes or more,
> > you're doing something wrong. With a decent disk subsystem this is
> > expected to take a few *seconds* (5 - 10 seconds would be my estimate
> > based on what we see here with a larger leases file).
> 
> Could there be issues with file permissions?
> 
> My guess is that the temporary file written can not be renamed because dhcpd does not have write permissions?
> 
> > 
> > Steinar Haug, Nethelp consulting, sthaug at nethelp.no <mailto:sthaug at nethelp.no>
> > _______________________________________________
> > dhcp-users mailing list
> > dhcp-users at lists.isc.org <mailto:dhcp-users at lists.isc.org>
> > https://lists.isc.org/mailman/listinfo/dhcp-users <https://lists.isc.org/mailman/listinfo/dhcp-users>
> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.isc.org/pipermail/dhcp-users/attachments/20191029/0985beda/attachment.htm>