[Samba] slow creating files
Al
mailinglist at theflux.net
Thu Feb 16 18:38:29 MST 2012
Agreed, run 'top d1' then look at the line:
Cpu(s): 0.5%us, 0.5%sy, 0.0%ni, 99.0%id, 0.0%wa, 0.0%hi,
0.0%si, 0.0%st
If you see '%wa' higher than 15.0 you have slow disk writing...
On Feb 16, 2012, at 12:36 AM, Pavel Plesov wrote:
> Hello,
> Have you checked the hardware ?
> Tools like dmesg, atop and iostat can be very helpful here.
> On Wed, Feb 8, 2012 at 17:10, Алексей Ганков
> <a.v.gankov at gmail.com> wrote:
>> We tried to migrate from old Windows fileserver (p4, single HDD) to
>> Samba
>> (FedoraCore15, Samba 3.5.12-72.fc15, ext4 volume, xeon, raid5).
>> Our pipeline is so, that some special software generates files on
>> that
>> fileserver.
>> The typical filesize ~50 mbytes.
>> On the old hardware, software (win2k3 server) the time of single file
>> creation was about 10 seconds. On the new configuration it takes
>> 20-25
>> seconds.
>> Copying of large files to\from samba server is ok (more than 80
>> mbytes\sec).
>> It was default Samba installation.
>> The usual tuning doesn't help at all (TCPNODELAY etc...)
>>
>> Is there any idea for tuning?
>>
>> Also, I wrote easy test that confused me:
>>
>> #include "stdio.h"
>> #include "stdlib.h"
>> #include "time.h"
>> void main(int argc, char *argv[])
>> {
>> int fsize=40000000;
>> int i=0;
>> FILE *to;
>> char
>> str
>> []=
>> "0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
>> ";
>> time_t start, end;
>> double diff;
>>
>> time(&start);
>> to=fopen(argv[1], "w+");
>> for(i=0; i < fsize/100; i++)
>> {
>> fprintf(to, "\n%7d-%s",i, str);
>> / fflush(to); // makes it slow!/
>> }
>> fclose(to);
>> time(&end);
>> diff=difftime(end,start);
>> printf("\n \t time_diff = %.2lf", diff);
>> }
>>
>> This was started on Win7 client PC, It creates about 40 mbytes size
>> file in
>> pointed path.
>> Comparing timings on our samba share and win2k3 share gives: ~40
>> seconds on
>> Samba and on 3-4 seconds win2k3!
>> That means that fflush cause dramatically slow down of fileshare.
>>
>> Alexey
>> --
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>
>
>
> --
> Pavel Plesov
> --
> To unsubscribe from this list go to the following URL and read the
> instructions: https://lists.samba.org/mailman/options/samba
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