We did last fall (ISC DHCP on Dell Servers running RedHat Enterprise Linux). Although the CPU load was fine, we were having disk I/O issues resulting in the server not responding to requests.
- Quick Fix was to bring up DHCP on additional boxes and spread the scopes out. - Long term fix consisted of two parts: - Enabled asynchronous logging on the syslog process - On the DHCP servers for wireless subnets (which use a 20 minute lease time) we put the DHCP lease file on a RAM disk (not quite in the spirit of the DHCP RFC's, but greatly improved performance). -Neil -- Neil Johnson Network Engineer The University of Iowa Phone: 319 384-0938 Fax: 319 335-2951 Mobile: 319 540-2081 E-Mail: neil-john...@uiowa.edu On 8/27/12 1:19 PM, "Hanset, Philippe C" <phan...@utk.edu> wrote: >All, > >(trying to help our systems group by asking this list) > >Have any of you experienced DHCP issues due to too many machines >requesting leases? > >We run two ISC DHCP servers (in Active-Active mode) with 30 minutes lease >time >Running on SUN V440, no unusual I/O load, no unusual CPU load and >ethernet is fine. > >DHCP is literally not responding to lease requests, on wired and on >wireless. > >We were fine during the summer (with 5000 concurrent users), but we are >not now with 14,000 concurrent users. > >Thanks, > >Philippe > >Philippe Hanset >University of Tennessee, Knoxville >www.eduroamus.org >********** >Participation and subscription information for this EDUCAUSE Constituent >Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
