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fsyncs on software raid on FusionIO


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As soon as we get couple FusionIO cards, there is question how to join them in single space for database. FusionIO does not provide any mirroring/stripping solutions and totally relies on OS tools there.

So for Linux we have software RAID and LVM, I tried to followup on my post
How many fsync / sec FusionIO can handle, and check what overhead we can expect using additional layers over FusionIO card.

The card I used is

, physically it is two cards on single board, and visible as two cards to OS.

By some reason I was not able to setup LVM on cards, so I’ve finished tests only for software RAID0 and RAID1.

I used XFS filesystem mounted with “-o nobarrier” option, and I’ve the test I used in previous post on next configurations:

  • Single card
  • RAID0 over two cards
  • RAID1 over two cards

There what I’ve got:

  • Single card: 14050.59 req/sec
  • RAID0: 13039.00 req/sec
  • RAID1: 324.71 req/sec

By single card I’ve results much better than in my previous test, probably
Duo card has better characteristics.

RAID0 shows some overhead 8%, but it is acceptable.

And something is terrible wrong with RAID1, I am getting 40x drops in amount of fsyncs.
So it seems we can’t use innodb transactional log files with

on software RAID1 over FusionIO.

For reference I used command:

And next steps is to check how RAID setup affects IO throughput.

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Vadim Tkachenko

Vadim leads Percona's development group, which produces Percona Clould Tools, the Percona Server, Percona XraDB Cluster and Percona XtraBackup. He is an expert in solid-state storage, and has helped many hardware and software providers succeed in the MySQL market.



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