Different performance

Tina Tian tinatianxia at hotmail.com
Mon May 12 17:36:47 UTC 2008


 
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 bytes255 heads, 63 sectors/track, 8844 cylindersUnits = 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 bytes255 heads, 63 sectors/track, 72809 cylindersUnits = 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:1Adding 2097144k swap on /dev/VolGroup_ID_27777/LogVol0.  Priority:-2 extents:1
 
Host 2, fdisk -l
----------------
Disk /dev/sda: 72.7 GB, 72746008576 bytes255 heads, 63 sectors/track, 8844 cylindersUnits = 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 bytes255 heads, 63 sectors/track, 72809 cylindersUnits = 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 bytes255 heads, 63 sectors/track, 36404 cylindersUnits = 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 bytes255 heads, 63 sectors/track, 38913 cylindersUnits = 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 swapAdding 1769464k swap on /dev/VolGroup_ID_787/LogVol0.  Priority:-1 extents:1
 
Best Regards,
Tina


Date: Mon, 12 May 2008 07:11:12 -0500From: jolt at ti.comTo: redhat-sysadmin-list at redhat.comSubject: RE: Different performance






Tina,
 
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.
 
Regards,
 
Joseph
 




From: redhat-sysadmin-list-bounces at redhat.com [mailto:redhat-sysadmin-list-bounces at redhat.com] On Behalf Of Tina TianSent: Friday, May 09, 2008 10:42 PMTo: redhat-sysadmin-list at redhat.comSubject: RE: Different performance
 
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



To: redhat-sysadmin-list at redhat.comDate: Fri, 9 May 2008 16:58:19 -0600From: larry.sorensen at juno.comSubject: Re: Different performance

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?

 

On Fri, 9 May 2008 14:11:25 -0700 Tina Tian <tinatianxia at hotmail.com> writes:


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=====================
 
avg-cpu:  %user   %nice    %sys %iowait   %idle
           0.15    0.00    0.07    0.28   99.49
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
 
avg-cpu:  %user   %nice    %sys %iowait   %idle
          15.74    0.00    8.99    0.31   74.95
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
 
avg-cpu:  %user   %nice    %sys %iowait   %idle
           6.18    0.00    2.37    9.24   82.20
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
 
avg-cpu:  %user   %nice    %sys %iowait   %idle
           0.06    0.00    0.12   12.44   87.38
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
 
avg-cpu:  %user   %nice    %sys %iowait   %idle
           0.00    0.00    0.12   12.49   87.38
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
 
avg-cpu:  %user   %nice    %sys %iowait   %idle
           0.00    0.00    0.06   12.43   87.51
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
 
avg-cpu:  %user   %nice    %sys %iowait   %idle
           0.00    0.00    0.12   12.31   87.56
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
 
avg-cpu:  %user   %nice    %sys %iowait   %idle
           0.00    0.00    0.19   12.37   87.45
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
 
avg-cpu:  %user   %nice    %sys %iowait   %idle
           0.00    0.00    0.12   12.37   87.51
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
 
avg-cpu:  %user   %nice    %sys %iowait   %idle
           0.00    0.00    0.06   12.44   87.50
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
 
avg-cpu:  %user   %nice    %sys %iowait   %idle
           0.06    0.00    0.19   12.41   87.34
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
 
 
Host 2: iostat -x 2
==================
avg-cpu:  %user   %nice    %sys %iowait   %idle
           0.96    0.00    0.69    0.21   98.15
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
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
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
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
 
avg-cpu:  %user   %nice    %sys %iowait   %idle
          16.03    0.00    8.61    0.44   74.92
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
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
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
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
 
avg-cpu:  %user   %nice    %sys %iowait   %idle
          15.62    0.00    8.81    0.56   75.00
 
Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
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
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
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
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
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
 
 
Thanks,
Tina
 



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