[Openstack-operators] large high-performance ephemeral storage
jaypipes at gmail.com
Wed Jun 13 14:02:59 UTC 2018
On 06/13/2018 09:58 AM, Blair Bethwaite wrote:
> Hi all,
> Wondering if anyone can share experience with architecting Nova KVM
> boxes for large capacity high-performance storage? We have some
> particular use-cases that want both high-IOPs and large capacity local
> In the past we have used bcache with an SSD based RAID0 write-through
> caching for a hardware (PERC) backed RAID volume. This seemed to work
> ok, but we never really gave it a hard time. I guess if we followed a
> similar pattern today we would use lvmcache (or are people still using
> bcache with confidence?) with a few TB of NVMe and a NL-SAS array with
> write cache.
> Is the collective wisdom to use LVM based instances for these use-cases?
> Putting a host filesystem with qcow2 based disk images on it can't help
> performance-wise... Though we have not used LVM based instance storage
> before, are there any significant gotchas? And furthermore, is it
> possible to use set IO QoS limits on these?
I've found /dev/null to be the fastest ephemeral storage system, bar none.
Not sure if you can set QoS limits on it though.
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