Date: Sat, 25 Mar 2000 17:39:01 -0600 (CST) From: Kevin Day <toasty@dragondata.com> To: dgilbert@velocet.ca (David Gilbert) Cc: freebsd-current@FreeBSD.ORG, freebsd-scsi@FreeBSD.ORG Subject: Re: MegaRAID jiggles clock? Message-ID: <200003252339.RAA55426@celery.dragondata.com> In-Reply-To: <14557.18178.239025.747850@trooper.velocet.net> from "David Gilbert" at Mar 25, 2000 06:08:50 PM
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> > I'm wondering if the AMI MegaRAID controller/driver might be the > reason that I'm getting a large number of clock resets from ntpd. > About every half hour, ntpd seems to feel the need to reset the clock > on the server by about 1/3 of a second. The server has a moderate NFS > load (going out through 12 dc interfaces) and an AMI MegaRAID 1400 > controller with 8 disks in a RAID-5 config. > > I have other servers with 12 dc ports, and havn't seen any > particularly bad time performance from them, which is why I'm > suspicious of the megaraid. This machine is also using a motherboard > common to many of our other machines. None of our other servers (we > have a "ring" of 5 time servers to which all our internal hosts > connect) or clients appear to have any issues. > > I have considered setting the option on ntpd to only adjust time by > adjusting the frequency ... to see if this is just a bogon clock chip > or somesuch. > > ideas? > > Dave. > Granted, this is an old 4.0-current machine(from around September), but.... I've seen heavy NFS server load affect the clocks on all three of my NFS servers. The heavier the load, the faster the clock seems to run. Mar 25 10:00:01 nfs ntpdate[75363]: adjust time server 192.160.127.90 offset -0.028636 Mar 25 11:00:02 nfs ntpdate[75406]: adjust time server 192.160.127.90 offset -0.033046 Mar 25 12:00:01 nfs ntpdate[75448]: adjust time server 192.160.127.90 offset -0.031371 Mar 25 13:00:01 nfs ntpdate[75490]: adjust time server 192.160.127.90 offset -0.030030 Mar 25 14:00:01 nfs ntpdate[75532]: adjust time server 192.160.127.90 offset -0.031346 Mar 25 15:00:00 nfs ntpdate[75573]: adjust time server 192.160.127.90 offset -0.030992 Mar 25 16:00:00 nfs ntpdate[75616]: adjust time server 192.160.127.90 offset -0.031654 Mar 25 17:00:00 nfs ntpdate[75657]: adjust time server 192.160.127.90 offset -0.031354 Because my NFS load isn't consistant throughout the day, xntpd seems to really freak out about trying to keep it balanced. Relevant info: Timecounter "i8254" frequency 1193182 Hz Timecounter "TSC" frequency 337194185 Hz CPU: AMD-K6(tm) 3D processor (337.19-MHz 586-class CPU) Origin = "AuthenticAMD" Id = 0x580 Stepping = 0 Features=0x8001bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8,MMX> AMD Features=0x80000800<SYSCALL,3DNow!> real memory = 134217728 (131072K bytes) avail memory = 126246912 (123288K bytes) vinum: loaded npx0: <math processor> on motherboard npx0: INT 16 interface pcib0: <AcerLabs M1541 (Aladdin-V) PCI host bridge> on motherboard pci0: <PCI bus> on pcib0 pcib1: <AcerLabs M5243 PCI-PCI bridge> at device 1.0 on pci0 pci1: <PCI bus> on pcib1 isab0: <AcerLabs M1533 portable PCI-ISA bridge> at device 7.0 on pci0 isa0: <ISA bus> on isab0 fxp0: <Intel EtherExpress Pro 10/100B Ethernet> irq 11 at device 14.0 on pci0 fxp0: Ethernet address 00:90:27:34:c1:ec ata-pci0: <AcerLabs Aladdin IDE controller> irq 0 at device 15.0 on pci0 ata-pci0: Busmastering DMA supported ata0 at 0x01f0 irq 14 on ata-pci0 ata1 at 0x0170 irq 15 on ata-pci0 vga-pci0: <ATI model 4750 graphics accelerator> at device 16.0 on pci0 pn0: <82c169 PNIC 10/100BaseTX> irq 10 at device 18.0 on pci0 pn0: Ethernet address: 00:a0:cc:3e:c6:3d pn0: autoneg complete, link status good (full-duplex, 100Mbps) ahc0: <Adaptec 2940A Ultra SCSI adapter> irq 9 at device 20.0 on pci0 ahc0: aic7860 Single Channel A, SCSI Id=7, 3/255 SCBs ata0: master: setting up UDMA2 mode on Aladdin chip OK -- Kevin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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