[Lustre-discuss] lustre performance question (contd)

Aaron Knister aaron at iges.org
Tue Dec 25 09:27:10 PST 2007


You really like collectl! I've seen it mentioned here many times.  
Perhaps I'll actually give it a shot! :) It sounds like a great piece  
of software. Is there a standard way to centrally log collectl stats?

On Dec 25, 2007, at 11:38 AM, Mark Seger wrote:

> As a collectl-ism, it looks like you're running it in a mode that  
> requests data distribution by ost, which is great when there's a lot  
> of different things going on in each ost.  But if you run things in  
> summary mode little 'l' instead of 'L', you'll see one line per  
> sample without all the header crap that separates out each sample as  
> shown here.  I've also tossed in -oT to include timestamps.  The  
> reasons for all the 0's is because there is currently no traffic,  
> but I think you'll get the idea
>
> [root at hpcsfsa3 ~]# collectl -s l -OB
> waiting for 1 second sample...
>
> # LUSTRE FILESYSTEM SUMMARY
> #         <-----------------------reads----------------------- OST  
> -------------------writes------------------------->
> #         Rds  RdK   1P   2P   4P   8P  16P  32P  64P 128P 256P 512P  
> 1024P Wrts WrtK   1P   2P   4P   8P  16P  32P  64P 128P 256P 512P  
> 1024P
> 11:37:04    0    0    0    0    0    0    0    0    0    0    0     
> 0    0    0    0    0    0    0    0    0    0    0    0    0     
> 0    0
> 11:37:05    0    0    0    0    0    0    0    0    0    0    0     
> 0    0    0    0    0    0    0    0    0    0    0    0    0     
> 0    0
> 11:37:06    0    0    0    0    0    0    0    0    0    0    0     
> 0    0    0    0    0    0    0    0    0    0    0    0    0     
> 0    0
> 11:37:07    0    0    0    0    0    0    0    0    0    0    0     
> 0    0    0    0    0    0    0    0    0    0    0    0    0     
> 0    0
> 11:37:08    0    0    0    0    0    0    0    0    0    0    0     
> 0    0    0    0    0    0    0    0    0    0    0    0    0     
> 0    0
> 11:37:09    0    0    0    0    0    0    0    0    0    0    0     
> 0    0    0    0    0    0    0    0    0    0    0    0    0     
> 0    0
> 11:37:10    0    0    0    0    0    0    0    0    0    0    0     
> 0    0    0    0    0    0    0    0    0    0    0    0    0     
> 0    0
>
> -mark
>
> Balagopal Pillai wrote:
>> On Tue, 25 Dec 2007, Aaron Knister wrote:
>> Looks like there were lots of tiny writes (no reads) at the time  
>> when this happened. Can't really blame the tiny writes. I was  
>> testing with making the tar file out of /usr/lib!. Here is the  
>> playback from colletcl on a simple tar right after the the volume  
>> data1 is mounted.
>> ### RECORD    7 >>> lustre1 <<< (1198592822) (Tue Dec 25 10:27:02  
>> 2007) ###
>>
>> # LUSTRE FILESYSTEM SINGLE OST STATISTICS
>> #Ost               Rds  RdK   1K   2K   4K   8K  16K  32K  64K 128K  
>> 256K Wrts WrtK   1K   2K   4K   8K  16K  32K  64K 128K 256K
>> data1-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0  207 429M    0    0    0    0    0    0    2    0
>> data2-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data3-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data4-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>>
>>
>>
>>         There is 429M of 1k i/o. Here is the collectl playback when  
>> the data1 starts working normally, after 10 - 15 minutes of mounting.
>>
>> ### RECORD    5 >>> lustre1 <<< (1198598746) (Tue Dec 25 12:05:46  
>> 2007) ###
>>
>> # LUSTRE FILESYSTEM SINGLE OST STATISTICS
>> #Ost               Rds  RdK   1K   2K   4K   8K  16K  32K  64K 128K  
>> 256K Wrts WrtK   1K   2K   4K   8K  16K  32K  64K 128K 256K
>> data1-OST0000       18  17K    0    0    1    0    0    0    0     
>> 0   17   10  10K    0    0    0    0    0    0    0    0   10
>> data2-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data3-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data4-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>>
>> ### RECORD    6 >>> lustre1 <<< (1198598757) (Tue Dec 25 12:05:57  
>> 2007) ###
>>
>> # LUSTRE FILESYSTEM SINGLE OST STATISTICS
>> #Ost               Rds  RdK   1K   2K   4K   8K  16K  32K  64K 128K  
>> 256K Wrts WrtK   1K   2K   4K   8K  16K  32K  64K 128K 256K
>> data1-OST0000      222 3625    7    5  195   15    0    0    0     
>> 0    0    1  403    0    0    0    0    0    0    0    0    0
>> data2-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data3-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data4-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>>
>> ### RECORD    7 >>> lustre1 <<< (1198598767) (Tue Dec 25 12:06:07  
>> 2007) ###
>>
>> # LUSTRE FILESYSTEM SINGLE OST STATISTICS
>> #Ost               Rds  RdK   1K   2K   4K   8K  16K  32K  64K 128K  
>> 256K Wrts WrtK   1K   2K   4K   8K  16K  32K  64K 128K 256K
>> data1-OST0000       53  846    2    1   46    4    0    0    0     
>> 0    0    2 1866    0    0    0    0    0    0    0    0    1
>> data2-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data3-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data4-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>>
>> ### RECORD    8 >>> lustre1 <<< (1198598777) (Tue Dec 25 12:06:17  
>> 2007) ###
>>
>> # LUSTRE FILESYSTEM SINGLE OST STATISTICS
>> #Ost               Rds  RdK   1K   2K   4K   8K  16K  32K  64K 128K  
>> 256K Wrts WrtK   1K   2K   4K   8K  16K  32K  64K 128K 256K
>> data1-OST0000       11  10K    0    0    1    0    0    0    0     
>> 0   10    8 8499    0    0    0    0    0    0    0    0    9
>> data2-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data3-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data4-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>>
>> ### RECORD    9 >>> lustre1 <<< (1198598787) (Tue Dec 25 12:06:27  
>> 2007) ###
>>
>> # LUSTRE FILESYSTEM SINGLE OST STATISTICS
>> #Ost               Rds  RdK   1K   2K   4K   8K  16K  32K  64K 128K  
>> 256K Wrts WrtK   1K   2K   4K   8K  16K  32K  64K 128K 256K
>> data1-OST0000      245 3914    2    6  222   15    0    0    0     
>> 0    0    2  421    0    0    1    0    0    0    0    0    0
>> data2-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data3-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data4-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>>
>> ### RECORD   10 >>> lustre1 <<< (1198598797) (Tue Dec 25 12:06:37  
>> 2007) ###
>>
>> # LUSTRE FILESYSTEM SINGLE OST STATISTICS
>> #Ost               Rds  RdK   1K   2K   4K   8K  16K  32K  64K 128K  
>> 256K Wrts WrtK   1K   2K   4K   8K  16K  32K  64K 128K 256K
>> data1-OST0000      105 1678    5    4   84   12    0    0    0     
>> 0    0    3  171    0    0    2    1    0    0    0    0    0
>> data2-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data3-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> data4-OST0000        0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch1-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0000     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>> scratch2-OST0001     0    0    0    0    0    0    0    0    0     
>> 0    0    0    0    0    0    0    0    0    0    0    0    0
>>
>> ### RECORD   11 >>> lustre1 <<< (1198598807) (Tue Dec 25 12:06:47  
>> 2007) ###
>>
>>          This looks normal. I am seeing the same thing on another  
>> Lustre installation (1.6.0.1) occassionally. But it goes away after  
>> a while.
>>
>> Balagopal
>>
>>
>>
>>> When the volume is slugish do you see lots of tiny reads (500k/ 
>>> sec) on the
>>> full volume? When it slows down could you run an "iostat -k 2" on  
>>> the OSS in
>>> question? I think we may be having the same problem. I could find no
>>> answer/solution and ended up blowing the whole setup away and  
>>> starting from
>>> scratch. I'd like to track this down and figure out if its  
>>> actually a bug or
>>> whether I FUBAR'd something in my setup.
>>>
>>> -Aaron
>>>
>>> On Dec 25, 2007, at 9:42 AM, Balagopal Pillai wrote:
>>>
>>>
>>>> Hi,
>>>>
>>>>   Please ignore the previous email. It seemed to solve itself  
>>>> after 10
>>>> - 15 minutes of mounting the filled volume. Now it is as fast as  
>>>> the empty
>>>> volumes.
>>>>
>>>> Thanks
>>>> Balagopal
>>>>
>>>> ---------- Forwarded message ----------
>>>> Date: Tue, 25 Dec 2007 10:36:28 -0400 (AST)
>>>> From: Balagopal Pillai <pillai at mathstat.dal.ca>
>>>> To:  <lustre-discuss at clusterfs.com>
>>>> Subject: lustre performance question
>>>>
>>>> Hi,
>>>>
>>>>       We have one Lustre volume that is getting full and some other
>>>> volumes that are totally empty. The one that is full is a little  
>>>> sluggish
>>>> at times with the following messages appearing in syslog on the  
>>>> OSS -
>>>>
>>>> Lustre: 5809:0:(filter_io_26.c:698:filter_commitrw_write()) data1- 
>>>> OST0001:
>>>> slow i_mutex 82s
>>>> Lustre: 5809:0:(filter_io_26.c:711:filter_commitrw_write()) data1- 
>>>> OST0001:
>>>> slow brw_start 82s
>>>> Lustre: 5809:0:(filter_io_26.c:763:filter_commitrw_write()) data1- 
>>>> OST0001:
>>>> slow direct_io 82s
>>>> Lustre: 5809:0:(filter_io_26.c:776:filter_commitrw_write()) data1- 
>>>> OST0001:
>>>> slow commitrw commit 82s
>>>>
>>>>         But the same two OSS are also exporting the empty volume,  
>>>> which
>>>> is very fast on any tests (like creation of a tar file, bonnie  
>>>> etc etc)
>>>> I also tested the same thing on the nfs exported backup volume of  
>>>> the
>>>> filled up lustre volume (exported from the same OSS server) and  
>>>> it doesn't
>>>> show any significant slow down. Is it normal for Lustre volumes  
>>>> to slow
>>>> down when the volumes get full?
>>>>
>>>> Thanks
>>>> Balagopal
>>>>
>>>> _______________________________________________
>>>> Lustre-discuss mailing list
>>>> Lustre-discuss at clusterfs.com
>>>> https://mail.clusterfs.com/mailman/listinfo/lustre-discuss
>>>>
>>> Aaron Knister
>>> Associate Systems Analyst
>>> Center for Ocean-Land-Atmosphere Studies
>>>
>>> (301) 595-7000
>>> aaron at iges.org
>>>
>>>
>>>
>>>
>>
>> _______________________________________________
>> Lustre-discuss mailing list
>> Lustre-discuss at clusterfs.com
>> https://mail.clusterfs.com/mailman/listinfo/lustre-discuss
>>
>

Aaron Knister
Associate Systems Analyst
Center for Ocean-Land-Atmosphere Studies

(301) 595-7000
aaron at iges.org







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