[Lustre-discuss] iozone slow read for 64k record size 2.4 vs. 1.8.9

[JS Landry]

On 29/08/13 07:03 PM, JS Landry wrote:
> Hi,I'm testing lustre 2.4 with iozone and I can't find why the read of
> 64k record size (1GB file) is so slow compare to 1.8.9client.
>
> 1.8.9 client
>                 KB  reclen   write rewrite    read    reread
>            1048576      64  677521  794456  6130161  6204552
>            1048576    1024  709112  862278  7165733  7152088
>
> 2.4.0 client
>                 KB  reclen   write rewrite    read    reread
>            1048576      64  682344  897808  2334044  2331080
>            1048576    1024  868466 1217273  4599784  4610098
>


I run collectl -scml while running iozone, and I don't know what is 
going on with the "lustre KBRead/Reads"
stuck at 4G on the 2.4.0 client.(the KBRead/Reads columns returned to 0 
when I unmount lustre.)
collectl works ok on 1.8.9. (same os, same hardware)


2.6.32-358.6.2.el6.x86_64
collectl-3.6.7-1.el6.noarch
lustre: 2.4.0
kernel: patchless_client
build: 2.4.0-RC2-gd3f91c4-PRISTINE-2.6.32-358.6.2.el6.x86_64



#<--------CPU--------><-----------Memory-----------><--------Lustre 
Client-------->
#cpu sys inter  ctxsw Free Buff Cach Inac Slab  Map KBRead  Reads  
KBWrite Writes
    6   6  2687   6132  20G    0   2G 171M 153M 322M 4096M     4G   
175232   2738
   21  21  5939  16537  19G    0   3G 812M 329M 322M 4096M     4G   
656704  10261
    6   6  2380   5751  19G    0   3G   1G 386M 322M 4096M     4G   
216640   3385
    3   3  1329   2773  19G    0   3G 915M 384M 322M 4096M     4G   
111168   1737
   24  24  6678  21347  19G    0   3G  74M 389M 322M 4096M     4G   
861376  13459
    2   2  1107   2082  19G    0   3G 272K 390M 322M 4096M     4G    
76032   1188
    0   0   500    141  19G    0   3G 272K 390M 322M 4096M     4G        
0      0
    6   6  1253    161  19G    0   3G 272K 390M 322M 4096M     4G        
0      0
    5   5  1132    139  19G    0   3G 272K 390M 322M 4096M     4G        
0      0
    5   5   987    360  19G    0   2G 272K 206M 322M 4096M     4G        
0      0
    2   2  1031    353  19G    0   2G 272K 115M 322M 4096M     4G        
0      0
   12  12  3490  10766  19G    0   2G 417M 220M 322M 4096M     4G   
427008    417
   16  16  4741  15475  19G    0   3G   1G 383M 322M 4096M     4G   
621568    607
    0   0   537    155  19G    0   3G   1G 384M 322M 4096M     4G        
0      0
   24  24  7451  24128  19G    0   3G 440K 386M 322M 4096M     4G  
1048576   1024
    0   0   640    176  19G    0   3G 272K 387M 322M 4096M     4G        
0      0
    2   2   752    133  19G    0   3G 272K 387M 322M 4096M     4G        
0      0


on the 1.8.9 client

2.6.32-358.6.2.el6.x86_64
collectl-3.6.7-1.el6.noarch
lustre: 1.8.9
kernel: patchless_client
build:  jenkins-wc1--PRISTINE-2.6.32-358.6.2.el6.x86_64


#<--------CPU--------><-----------Memory-----------><--------Lustre 
Client-------->
#cpu sys inter  ctxsw Free Buff Cach Inac Slab  Map KBRead  Reads  
KBWrite Writes
    3   3  1585   4267  19G    0   2G 824M 318M 231M 0      0   
205824    201
   14  14  5653  17881  19G    0   2G   1M 323M 231M 0      0   
842752    823
    0   0   745    181  19G    0   2G   1M 324M 231M 0      0        
0      0
    2   2   645    112  19G    0   2G   1M 323M 231M 1048580   
1025        0      0
    2   2   724    124  19G    0   2G   1M 323M 231M 1048580   
1025        0      0
   12  11  2044    859  20G    0   1G   1M 223M 233M 1      3        
0      0
   14  14  4807  13121  20G    0   2G 644M 282M 230M 0      0   658112  
10283
    8   8  3245   8196  19G    0   2G   1G 320M 230M 0      0   390464   
6101
    0   0   570    164  19G    0   2G   1G 320M 230M 0      0        
0      0
   11  11  4061  12627  19G    0   2G 421M 317M 230M 0      0   618496   
9664
    8   8  2953   9239  19G    0   2G   1M 321M 230M 0      0   430080   
6720
    2   2   699    127  19G    0   2G   1M 321M 230M 1048580    
16K        0      0
    0   0   576    148  19G    0   2G   1M 321M 230M 0      0        
0      0
    3   3   783    210  19G    0   2G   1M 282M 230M 1048580    
16K        0      0
    2   2   725    597  20G    0   1G  21M 219M 231M 0      0    
20480     20
   14  14  5253  14347  20G    0   2G 714M 287M 231M 0      0   
709632    693


Is this a known bug?
JS