<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:st1="urn:schemas-microsoft-com:office:smarttags" xmlns="http://www.w3.org/TR/REC-html40"> <head> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 11 (filtered medium)"> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PersonName"/>  <style>  </style> </head> <body lang=EN-US link=blue vlink=blue> <div class=Section1> Tina,<o:p></o:p> <o:p> </o:p> Could you run a vmstat output while under load to see how much memory is swapping and how quickly context switching is occurring? “vmstat 5 20”<o:p></o:p> Also, what kernel is running? “uname –a”<o:p></o:p> <o:p> </o:p> <div> <div class=MsoNormal align=center style='text-align:center'> <hr size=2 width="100%" align=center tabindex=-1> </div> From: redhat-sysadmin-list-bounces@redhat.com [mailto:redhat-sysadmin-list-bounces@redhat.com] On Behalf Of Tina Tian Sent: Monday, May 12, 2008 1:37 PM To: <st1:PersonName w:st="on">redhat-sysadmin-list@redhat.com</st1:PersonName> Subject: RE: Different performance<o:p></o:p> </div> <o:p> </o:p> Thank you, Joseph. Let me explain it. On both host 1 and host2, sybase software is in /sybase and sybase database is in /sybasedata. On host 2, we have amada backup software in /dev/sdc and I believe some amada demon was running when I ran iostat. (> From the output of host 2 you provided, the first stat shows sdc is taking some of the load). Host 2 do have additional higher performance drivers which are not being used by sybase database (/sybasedata) at all. Will database be benefit from their quicker swap? Belows are results from fdisk/mount/dmesg(swap) on host1 and host2. Host 1, fdisk -l: ----------------- Disk /dev/sda: 72.7 GB, 72746008576 bytes 255 heads, 63 sectors/track, 8844 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 1 4 32098+ de Dell Utility /dev/sda2 5 1279 10241437+ 83 Linux /dev/sda3 * 1280 1406 1020127+ 83 Linux /dev/sda4 1407 8844 59745735 5 Extended /dev/sda5 1407 8844 59745703+ 8e Linux LVM Disk /dev/sdb: 598.8 GB, 598879502336 bytes 255 heads, 63 sectors/track, 72809 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdb1 1 66868 537117178+ 83 Linux /dev/sdb2 66869 72809 47721082+ 5 Extended host 1, mount: --------------- /dev/mapper/VolGroup_ID_27777-LogVol2 on / type ext3 (rw) none on /proc type proc (rw) none on /sys type sysfs (rw) none on /dev/pts type devpts (rw,gid=5,mode=620) usbfs on /proc/bus/usb type usbfs (rw) /dev/sda3 on /boot type ext3 (rw) none on /dev/shm type tmpfs (rw) /dev/mapper/VolGroup_ID_27777-LogVol3 on /tmp type ext3 (rw) /dev/mapper/VolGroup_ID_27777-LogVol6 on /usr type ext3 (rw) /dev/mapper/VolGroup_ID_27777-LogVol5 on /var type ext3 (rw) /dev/mapper/VolGroup_ID_27777-LogVolHome on /home type ext3 (rw) /dev/mapper/VolGroup_ID_27777-LogVolSybase on /sybase type ext3 (rw) /dev/mapper/VolGroup_ID_27777-LogVolTranLog on /tranlog type ext3 (rw) /dev/sdb1 on /sybasedata type ext3 (rw) none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw) sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw) Host 1, dmesg|grep swap ------------------------ Adding 1998840k swap on /dev/VolGroup_ID_27777/LogVol1. Priority:-1 extents:1 Adding 2097144k swap on /dev/VolGroup_ID_27777/LogVol0. Priority:-2 extents:1 Host 2, fdisk -l ---------------- Disk /dev/sda: 72.7 GB, 72746008576 bytes 255 heads, 63 sectors/track, 8844 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 1 4 32098+ de Dell Utility /dev/sda2 5 1534 12289725 83 Linux /dev/sda3 * 1535 1661 1020127+ 83 Linux /dev/sda4 1662 8844 57697447+ 5 Extended /dev/sda5 1662 8844 57697416 8e Linux LVM Disk /dev/sdb: 598.8 GB, 598879502336 bytes 255 heads, 63 sectors/track, 72809 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdb1 * 1 72809 584838261 83 Linux Disk /dev/sdc: 299.4 GB, 299439751168 bytes 255 heads, 63 sectors/track, 36404 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdc1 1 4370 35101993+ 83 Linux /dev/sdc2 4371 36404 257313105 83 Linux Disk /dev/sdd: 320.0 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdd1 1 38913 312568641 83 Linux host 2, mount: --------------- /dev/mapper/VolGroup_ID_787-LogVol1 on / type ext3 (rw) none on /proc type proc (rw) none on /sys type sysfs (rw) none on /dev/pts type devpts (rw,gid=5,mode=620) usbfs on /proc/bus/usb type usbfs (rw) /dev/sda3 on /boot type ext3 (rw) none on /dev/shm type tmpfs (rw) /dev/mapper/VolGroup_ID_787-LogVol2 on /tmp type ext3 (rw) /dev/mapper/VolGroup_ID_787-LogVol5 on /usr type ext3 (rw) /dev/mapper/VolGroup_ID_787-LogVol4 on /var type ext3 (rw) /dev/mapper/VolGroup_ID_787-LogVolHome on /home type ext3 (rw) /dev/mapper/VolGroup_ID_787-LogVolSybase on /sybase type ext3 (rw) /dev/mapper/VolGroup_ID_787-LogVolTranlog on /tranlog type ext3 (rw) /dev/sdb1 on /sybasedata type ext3 (rw) /dev/sdc1 on /pkgs type ext3 (rw) /dev/sdc2 on /amanda-data type ext3 (rw) none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw) sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw) host 2 dmesg |grep swap: ------------------------ host 1 : dmesg |grep swap Adding 1769464k swap on /dev/VolGroup_ID_787/LogVol0. Priority:-1 extents:1 Best Regards, Tina<o:p></o:p> <div class=MsoNormal align=center style='text-align:center'> <hr size=2 width="100%" align=center> </div> Date: Mon, 12 May 2008 07:11:12 -0500 From: jolt@ti.com To: <st1:PersonName w:st="on">redhat-sysadmin-list@redhat.com</st1:PersonName> Subject: RE: Different performance<o:p></o:p> <div> Tina,<o:p></o:p> <o:p></o:p> How are the partitions laid out on the two systems? It is likely that something OS related is accessing sda and sdb or host 1 while being spread across more disks in host 2. From the output of host 2 you provided, the first stat shows sdc is taking some of the load. Regardless of the RAM being the same in both systems, is there much swapping? Swapping on higher performance drives will be quicker.<o:p></o:p> <o:p></o:p> Regards,<o:p></o:p> <o:p></o:p> Joseph<o:p></o:p> <o:p></o:p> <div> <div class=MsoNormal align=center style='text-align:center'> <hr size=2 width="100%" align=center> </div> From: redhat-sysadmin-list-bounces@redhat.com [mailto:redhat-sysadmin-list-bounces@redhat.com] On Behalf Of Tina Tian Sent: Friday, May 09, 2008 10:42 PM To: <st1:PersonName w:st="on">redhat-sysadmin-list@redhat.com</st1:PersonName> Subject: RE: Different performance<o:p></o:p> </div> <o:p></o:p> The DB is Sybase ASE 15.0.2. Identical configuration on two hosts. My SA also confirmed that two hosts are almost identical except host2(faster DB load) has extra two disks sdc and sdd, sdc and sdd are with higer RPM=15k. The rest of disks sda and adb are identical on two hosts, with RPM=7k. On both host 1 and host 2, DBs are on /dev/sdb only. Best Regards, Tina<o:p></o:p> <div class=MsoNormal align=center style='text-align:center'> <hr size=2 width="100%" align=center> </div> To: <st1:PersonName w:st="on">redhat-sysadmin-list@redhat.com</st1:PersonName> Date: Fri, 9 May 2008 16:58:19 -0600 From: larry.sorensen@juno.com Subject: Re: Different performance<o:p></o:p> <div> Please include information on the databases including versions. It could just be different configurations on the databases. Are the patches up to date and equal on both servers?<o:p></o:p> </div> <div> <o:p></o:p> </div> <div> On Fri, 9 May 2008 14:11:25 -0700 Tina Tian <<a href="mailto:tinatianxia@hotmail.com">tinatianxia@hotmail.com</a>> writes:<o:p></o:p> </div> <blockquote style='border:none;border-left:solid black 1.5pt;padding:0in 0in 0in 8.0pt; margin-left:7.5pt;margin-top:5.0pt;margin-bottom:5.0pt'> <div> I am a DBA. I have identical database servers running on two Linux redhat 4, host 1 and host 2. When I was running the same bulk load to database (load a data file to database), host 2 was much faster than host 1. On both host1 and host2, database are using file system mount on /dev/sda and /dev/sdb. I checked with my SA, host1 and host2 have same CPU, RAM, file system configuration. The only different is that host 2 has extra HD capacity with higher 15k RPM. But the extra 2 HDs(sdc and sdd) are dedicated to other applications, not used by database at all. My questions are: ----------------- 1. On host2 (faster), the extra faster HDs(/dev/sdc and sdd) are not used by database. Does it still affect IO performance of /dev/sda and /dev/sdb ? 2. During database bulk load testing, host 1(slower) shows longer service IO time (svctm) and longer IO waiting time(await). What other possible reason can cause this problem? Any idea? I did post the same issue to database discussion group and they suggested me to check OS performance(svctm). Below is the result from iostat on host1(slower) and host2(faster) during bulk load: Host 1: iostat -x 2 =====================<o:p></o:p> </div> <o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 0.15 0.00 0.07 0.28 99.49<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> sda 0.01 0.59 0.24 0.19 29.22 6.17 14.61 3.08 83.49 0.01 21.71 3.84 0.16<o:p></o:p> sdb 0.04 10.05 0.89 3.74 117.37 110.34 58.69 55.17 49.13 0.10 21.76 4.48 2.08<o:p></o:p> <o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 15.74 0.00 8.99 0.31 74.95<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> sda 1.99 0.00 57.71 0.00 14025.87 0.00 7012.94 0.00 243.03 0.21 3.58 3.53 20.35<o:p></o:p> sdb 0.00 0.00 11.94 0.00 95.52 0.00 47.76 0.00 8.00 0.02 2.04 2.04 2.44<o:p></o:p> <o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 6.18 0.00 2.37 9.24 82.20<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> sda 0.50 0.50 23.00 1.00 5732.00 12.00 2866.00 6.00 239.33 0.07 3.08 3.02 7.25<o:p></o:p> sdb 0.00 129.00 7.00 130.00 56.00 2076.00 28.00 1038.00 15.56 0.75 5.49 5.40 73.95<o:p></o:p> <o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 0.06 0.00 0.12 12.44 87.38<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> sda 0.00 3.50 0.00 3.00 0.00 52.00 0.00 26.00 17.33 0.03 10.00 3.67 1.10<o:p></o:p> sdb 0.00 182.50 0.00 182.50 0.00 2920.00 0.00 1460.00 16.00 0.99 5.44 5.44 99.30<o:p></o:p> <o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 0.00 0.00 0.12 12.49 87.38<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> sda 0.00 0.50 0.00 1.01 0.00 12.06 0.00 6.03 12.00 0.01 6.00 6.00 0.60<o:p></o:p> sdb 0.00 184.92 0.00 185.43 0.00 2962.81 0.00 1481.41 15.98 1.01 5.45 5.38 99.70<o:p></o:p> <o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 0.00 0.00 0.06 12.43 87.51<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> sda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00<o:p></o:p> sdb 0.00 184.08 0.00 184.08 0.00 2945.27 0.00 1472.64 16.00 0.99 5.39 5.38 99.00<o:p></o:p> <o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 0.00 0.00 0.12 12.31 87.56<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> sda 0.00 1.00 0.00 1.50 0.00 20.00 0.00 10.00 13.33 0.02 15.33 6.67 1.00<o:p></o:p> sdb 0.00 181.00 0.00 181.00 0.00 2896.00 0.00 1448.00 16.00 0.99 5.48 5.49 99.40<o:p></o:p> <o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 0.00 0.00 0.19 12.37 87.45<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> sda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00<o:p></o:p> sdb 0.00 178.00 0.00 178.50 0.00 2852.00 0.00 1426.00 15.98 1.00 5.61 5.55 99.10<o:p></o:p> <o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 0.00 0.00 0.12 12.37 87.51<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> sda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00<o:p></o:p> sdb 0.00 179.50 0.00 179.50 0.00 2872.00 0.00 1436.00 16.00 0.99 5.52 5.53 99.25<o:p></o:p> <o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 0.00 0.00 0.06 12.44 87.50<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> sda 0.00 1.50 0.00 3.50 0.00 40.00 0.00 20.00 11.43 0.07 20.00 4.00 1.40<o:p></o:p> sdb 0.00 179.00 0.00 179.50 0.00 2868.00 0.00 1434.00 15.98 1.02 5.68 5.53 99.30<o:p></o:p> <o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 0.06 0.00 0.19 12.41 87.34<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> sda 0.00 0.50 0.00 1.00 0.00 12.00 0.00 6.00 12.00 0.01 6.50 6.50 0.65<o:p></o:p> sdb 0.00 183.50 0.00 183.50 0.00 2936.00 0.00 1468.00 16.00 0.99 5.40 5.41 99.25<o:p></o:p> <o:p></o:p> <o:p></o:p> Host 2: iostat -x 2<o:p></o:p> ==================<o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 0.96 0.00 0.69 0.21 98.15<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> hda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 48.00 0.00 1.33 1.33 0.00<o:p></o:p> sda 0.01 5.31 0.23 1.55 17.96 54.93 8.98 27.47 40.76 0.07 41.59 1.21 0.22<o:p></o:p> sdb 0.03 3.99 0.84 0.47 113.52 35.67 56.76 17.83 114.36 0.03 23.00 2.55 0.33<o:p></o:p> sdc 0.05 37.80 0.58 1.50 131.96 314.37 65.98 157.19 214.93 0.43 205.85 2.84 0.59<o:p></o:p> sdd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 40.35 0.00 3.52 3.52 0.00<o:p></o:p> <o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 16.03 0.00 8.61 0.44 74.92<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> hda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00<o:p></o:p> sda 1.99 14.43 57.71 6.97 13775.12 171.14 6887.56 85.57 215.63 0.22 3.43 3.36 21.74<o:p></o:p> sdb 0.00 357.71 7.96 358.71 63.68 5731.34 31.84 2865.67 15.80 0.04 0.10 0.10 3.83<o:p></o:p> sdc 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00<o:p></o:p> sdd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00<o:p></o:p> <o:p></o:p> avg-cpu: %user %nice %sys %iowait %idle<o:p></o:p> 15.62 0.00 8.81 0.56 75.00<o:p></o:p> <o:p></o:p> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util<o:p></o:p> hda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00<o:p></o:p> sda 1.50 0.00 56.00 0.00 13964.00 0.00 6982.00 0.00 249.36 0.22 3.90 3.89 21.80<o:p></o:p> sdb 0.00 635.00 7.00 635.00 64.00 10160.00 32.00 5080.00 15.93 0.06 0.09 0.09 5.55<o:p></o:p> sdc 0.00 1.00 0.00 1.50 0.00 20.00 0.00 10.00 13.33 0.00 0.00 0.00 0.00<o:p></o:p> sdd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00<o:p></o:p> <o:p></o:p> <o:p></o:p> Thanks,<o:p></o:p> Tina<o:p></o:p> <o:p></o:p> <div class=MsoNormal align=center style='text-align:center'> <hr size=2 width="100%" align=center> </div> Sign in and you could WIN! 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