Hello,
I read a long time ago theses very interesting benchmarks : http://symas.com/mdb/microbench/july/.
It seams that ext2 is the fastest filesystem for asynchronous writes.
Do you think an ext4 filesystem without journalisation but with extents could be faster ?
A LMBD database is a big flat file isn't it ? Extents are very interesting with that kind of files, aren't they ?
Did someone try it ?
Regards
Julien Huon wrote:
Hello,
I read a long time ago theses very interesting benchmarks : http://symas.com/mdb/microbench/july/.
It seams that ext2 is the fastest filesystem for asynchronous writes.
Do you think an ext4 filesystem without journalisation but with extents could be faster ?
For sequential writes, maybe. (But in that case, JFS with extents is still faster.) For random, probably not.
A LMBD database is a big flat file isnt it ?
Yes.
Extents are very interesting with that kind of files, arent they ?
For sequential access.
Did someone try it ?
Regards
Thanks Howard. ________________________________________ De : Howard Chu [hyc@symas.com] Envoyé : jeudi 23 octobre 2014 20:07 À : Julien Huon; openldap-technical@openldap.org Objet : Re: filesystem considerations
Julien Huon wrote:
Hello,
I read a long time ago theses very interesting benchmarks : http://symas.com/mdb/microbench/july/.
It seams that ext2 is the fastest filesystem for asynchronous writes.
Do you think an ext4 filesystem without journalisation but with extents could be faster ?
For sequential writes, maybe. (But in that case, JFS with extents is still faster.) For random, probably not.
A LMBD database is a big flat file isn’t it ?
Yes.
Extents are very interesting with that kind of files, aren’t they ?
For sequential access.
Did someone try it ?
Regards
-- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/
Julien Huon Julien.Huon@aduneo.com schrieb am 23.10.2014 um 18:06 in
Nachricht 571e5e67216d40a0b3943a660e73955c@VATICAN.aduneo.com:
Hello,
I read a long time ago theses very interesting benchmarks : http://symas.com/mdb/microbench/july/.
It seams that ext2 is the fastest filesystem for asynchronous writes.
Do you think an ext4 filesystem without journalisation but with extents could be faster ?
A LMBD database is a big flat file isn't it ? Extents are very interesting with that kind of files, aren't they ?
Hi!
I din't try ext4, because it's unsupported in SLES11, but I did a comparison of other filesystems for SLES11 SP2. Ext3 definitely isn't the worst choice; ext2 may be even faster. However xfs also performs quite well on large files. Usually the larger the blocks you are writing, the higher the throughput. And you must distinguish whether the buffer cache can buffer the asynchronous write or not. It also depends on the stroage technology you are using. I did my tests on a 4Gb FC-SAN with a RAID5 distributed on many disks (>20). ext3 also had peak read performance.
But for LMBD you would have to test mmap() operations specifically. Numbers may vary from traditional I/O operations.
Regards, Ulrich
Did someone try it ?
Regards
Hello Ulrich,
Interesting. Did you try JFS ?
Thanks you.
Regards
-----Message d'origine----- De : openldap-technical [mailto:openldap-technical-bounces@openldap.org] De la part de Ulrich Windl Envoyé : vendredi 24 octobre 2014 08:17 À : Julien Huon; openldap-technical@openldap.org Objet : Antw: filesystem considerations
Julien Huon Julien.Huon@aduneo.com schrieb am 23.10.2014 um 18:06 in
Nachricht 571e5e67216d40a0b3943a660e73955c@VATICAN.aduneo.com:
Hello,
I read a long time ago theses very interesting benchmarks : http://symas.com/mdb/microbench/july/.
It seams that ext2 is the fastest filesystem for asynchronous writes.
Do you think an ext4 filesystem without journalisation but with extents could be faster ?
A LMBD database is a big flat file isn't it ? Extents are very interesting with that kind of files, aren't they ?
Hi!
I din't try ext4, because it's unsupported in SLES11, but I did a comparison of other filesystems for SLES11 SP2. Ext3 definitely isn't the worst choice; ext2 may be even faster. However xfs also performs quite well on large files. Usually the larger the blocks you are writing, the higher the throughput. And you must distinguish whether the buffer cache can buffer the asynchronous write or not. It also depends on the stroage technology you are using. I did my tests on a 4Gb FC-SAN with a RAID5 distributed on many disks (>20). ext3 also had peak read performance.
But for LMBD you would have to test mmap() operations specifically. Numbers may vary from traditional I/O operations.
Regards, Ulrich
Did someone try it ?
Regards
openldap-technical@openldap.org
-
Howard Chu -
Julien Huon -
Ulrich Windl