[lustre-discuss] default directory striping with Lustre 2.8
Juan PC
piernas at ditec.um.es
Wed May 11 03:19:59 PDT 2016
Hello Olaf:
Thanks for replying. In my setup, each MDS also has a single MDT, and
each OSS has a single OST too. The difference, maybe, is that I have a
MDT and an OST running in the same server, and this seems to cause some
problems. I will try other configurations.
Regards,
Juan
El 10/05/16 a las 20:41, Faaland, Olaf P. escribió:
> Hello Juan,
>
> No, I haven't seen the problem you describe. Our testing configuration has only a single target per server - each MDS has a single MDT, and each OSS has a single OST.
>
> We've encountered some issues, but so far stability has been good. Our testing has been on relatively small scale, though.
>
> Olaf P. Faaland
> Livermore Computing
>
> ________________________________________
> From: Juan PC [piernas at ditec.um.es]
> Sent: Monday, May 09, 2016 4:25 AM
> To: Faaland, Olaf P.; lustre-discuss at lists.lustre.org
> Subject: Re: [lustre-discuss] default directory striping with Lustre 2.8
>
> Dear Olaf,
>
> I would like to hear about your experience with stripped directories in
> Lustre 2.8. Mine is that this feature is still unstable and a lot of
> "BUG: soft lockup..." errors start appearing. Maybe the problem is the
> setup that I use: as many OSTs as MDTs, with a pair OST-MDT per server.
>
> Have you faced the same problem?
>
> Regards,
>
> Juan
>
>
> El 05/05/16 a las 01:04, Faaland, Olaf P. escribió:
>> Hi,
>>
>> Suppose you have m MDTs in your filesystem, and create a new directory
>> and set default directory striping using
>>
>> lfs mkdir --count=c --index=k <path> && lfs setdirstripe --default
>> --count=c <path>
>>
>> Suppose that c < m and m > 2.
>>
>> Then you make subdirectories, like
>>
>> mkdir <path>/child.{1,2,3,...}
>>
>> a) By design, do the child directories have the same starting index as
>> <path>?
>> b) By design, are the child directories all striped across the same set
>> of MDTs as <path>?
>>
>> I didn't see that specified one way or the other in the DNE phase 2 high
>> level design document at
>> http://wiki.opensfs.org/DNE_StripedDirectories_HighLevelDesign_wiki_version.
>> If I should look elsewhere, let me know.
>>
>> In a test I was doing today, I noticed that neither (a) nor (b) were
>> true in practice. I'm wondering whether that's a bug or a feature.
>> Here's partial output from my test.
>>
>> $ lfs mkdir --count=6 --index=2 /p/lustre/faaland1/count6_index2
>> $ lfs setdirstripe -D --count=6 /p/lustre/faaland1/count6_index2
>> $ mkdir
>> /p/lustre/faaland1/count6_index2/subdir.{1,2,3,4,5,6,7,8,9,10,11,12,13,14}
>> $ lfs getdirstripe /p/lustre/faaland1/count6_index2
>> /p/lustre/faaland1/count6_index2
>> lmv_stripe_count: 6 lmv_stripe_offset: 2
>> mdtidx FID[seq:oid:ver]
>> 2 [0x280000400:0x33f3:0x0]
>> 3 [0x2c0000404:0x33f3:0x0]
>> 4 [0x300000402:0x33f2:0x0]
>> 5 [0x340000407:0x33f1:0x0]
>> 6 [0x380000406:0x33f0:0x0]
>> 7 [0x3c0000404:0x33ef:0x0]
>> /p/lustre/faaland1/count6_index2/subdir.4
>> lmv_stripe_count: 6 lmv_stripe_offset: 2
>> mdtidx FID[seq:oid:ver]
>> 2 [0x280000400:0x33f5:0x0]
>> 3 [0x2c0000404:0x33f5:0x0]
>> 4 [0x300000402:0x33f4:0x0]
>> 5 [0x340000407:0x33f3:0x0]
>> 6 [0x380000406:0x33f2:0x0]
>> 7 [0x3c0000404:0x33f1:0x0]
>> /p/lustre/faaland1/count6_index2/subdir.9
>> lmv_stripe_count: 6 lmv_stripe_offset: 5
>> mdtidx FID[seq:oid:ver]
>> 5 [0x340000400:0x37a1:0x0]
>> 6 [0x380000405:0x37a1:0x0]
>> 7 [0x3c0000402:0x37a0:0x0]
>> 8 [0x40000040e:0x379f:0x0]
>> 9 [0x440000403:0x379e:0x0]
>> 0 [0x200000405:0x379d:0x0]
>> /p/lustre/faaland1/count6_index2/subdir.3
>> lmv_stripe_count: 6 lmv_stripe_offset: 5
>> mdtidx FID[seq:oid:ver]
>> 5 [0x340000400:0x37a0:0x0]
>> 6 [0x380000405:0x37a0:0x0]
>> 7 [0x3c0000402:0x379f:0x0]
>> 8 [0x40000040e:0x379e:0x0]
>> 9 [0x440000403:0x379d:0x0]
>> 0 [0x200000405:0x379c:0x0]
>> /p/lustre/faaland1/count6_index2/subdir.14
>> lmv_stripe_count: 6 lmv_stripe_offset: 7
>> mdtidx FID[seq:oid:ver]
>> 7 [0x3c0000400:0x30d4:0x0]
>> 8 [0x400000403:0x30d4:0x0]
>> 9 [0x440000405:0x30d3:0x0]
>> 0 [0x200000407:0x30d2:0x0]
>> 1 [0x240000407:0x30d1:0x0]
>> 2 [0x280000407:0x30d0:0x0]
>> ...
>>
>>
>> Olaf P. Faaland
>> Livermore Computing
>> phone : 925-422-2263
>>
>>
>> _______________________________________________
>> lustre-discuss mailing list
>> lustre-discuss at lists.lustre.org
>> http://secure-web.cisco.com/1b6O1t0NM65SMDLd0VNnGkO8_2o0mWu7q_SotZhqVF-Z73mleDDzd45s2PwtZKJUD3Ztk-yckmuoGMq16E0Fw-LUq6hUtZjrPDpumyab9NGBeDZW21yP4CD9mliUhSCZwbhRAGnVnx6TJbxY-lfFJNAdY6Pdfv1hIx4bNQDu5cYl-aIXJWj15Y_Lum0LphN60mITae7Uf-w6xbGKd5g1bEyUK5SHoQ-NIJdGLF215kUypB_BB-96iWRj3tsoPdUp_ClSF7fBDItzoBV5jgOeHam7Ne6ztUVj7zqKJ8wQEEwJAC9CV_u7N7rLrxVaOVuFO2drWjpFe8tnmgn8tlPCjaH8Q4Y85Unr_I3dcOI4xZyo/http%3A%2F%2Flists.lustre.org%2Flistinfo.cgi%2Flustre-discuss-lustre.org
>>
>
>
> --
> D. Juan Piernas Cánovas
> Departamento de Ingeniería y Tecnología de Computadores
> Facultad de Informática. Universidad de Murcia
> Campus de Espinardo - 30080 Murcia (SPAIN)
> Tel.: +34868887657 Fax: +34868884151
> email: piernas at ditec.um.es
> PGP public key:
> http://pgp.rediris.es:11371/pks/lookup?search=piernas%40ditec.um.es&op=index
>
> *** Por favor, envíeme sus documentos en formato texto, HTML, PDF o
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>
--
D. Juan Piernas Cánovas
Departamento de Ingeniería y Tecnología de Computadores
Facultad de Informática. Universidad de Murcia
Campus de Espinardo - 30080 Murcia (SPAIN)
Tel.: +34868887657 Fax: +34868884151
email: piernas at ditec.um.es
PGP public key:
http://pgp.rediris.es:11371/pks/lookup?search=piernas%40ditec.um.es&op=index
*** Por favor, envíeme sus documentos en formato texto, HTML, PDF o
PostScript :-) ***
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