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From: Martin <m_btrfs@ml1.co.uk>
To: linux-btrfs@vger.kernel.org
Subject: Re: btrfs across a mix of SSDs & HDDs
Date: Wed, 02 May 2012 15:00:59 +0100	[thread overview]
Message-ID: <jnrems$tkh$1@dough.gmane.org> (raw)
In-Reply-To: <CAG1y0scNSit6oCvySUiP6RChx3_LLDY1QBML0BpGM-39etnZLQ@mail.gmail.com>

Thanks for good comments.


>> Is the OP using Oracle Linux?
> 
> He didn't say. But he didn't say he WON'T be using oracle linux (or
> other distro which supports btrfs) either. Plus the kernel can be
> installed on top of RHEL/Centos 5 and 6, so he can easily choose
> either the supported version, or the mainline version, each with its
> own consequences.

For further info:

Nope, not using Oracle Linux. Then again, I'm reasonably distro
agnostic. I'm also happy to compile my own kernels.

And the system in question uses a HDD RAID and looks to be more IOPS
bound rather than suffering actual IO data rate bound. The large
directories certainly don't help! It's running postfix + courier-imap at
the moment and I'm looking to revamp it for the gradually ever
increasing workload. CPU and RAM usage is low on average. It serves 2x
Gbit networks + internet users (3 NIC ports).

Hence I'm considering the best way for an revamp/upgrade. SSDs would
certainly help with the IOPS but I'm cautious about SSD wear-out for a
system that constantly thrashes through a lot of data. I could just
throw more disks at it to divide up the IO load.

Multiple pairs of "HDD paired with SSD on md RAID 1 mirror" is a thought
with ext4...

bcache looks ideal to help but also looks too 'experimental'.

And I was hoping that btrfs would help with handling the large
directories and multi-user parallel accesses, especially so for being
'mirrored' by btrfs itself (at the filesystem level) across 4 disks for
example.

Thoughts welcomed.


Is btrfs development at the 'optimising' stage now, or is it all still
very much a 'work in progress'?

Regards,
Martin


  reply	other threads:[~2012-05-02 14:00 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-01 19:35 btrfs across a mix of SSDs & HDDs Martin
2012-05-01 21:16 ` sam tygier
2012-05-02  0:56   ` Martin
2012-05-02  2:22 ` Bardur Arantsson
2012-05-02  4:28   ` Fajar A. Nugraha
2012-05-02  5:00     ` Bardur Arantsson
2012-05-02  5:30       ` Fajar A. Nugraha
2012-05-02 14:00         ` Martin [this message]
2012-05-02 18:41           ` Duncan
2012-05-02 23:54             ` vivo75
2012-05-03  0:46               ` Duncan

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