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From: Zdenek Kabelac <zkabelac@redhat.com>
To: LVM general discussion and development <linux-lvm@redhat.com>,
	Dale Stephenson <dalestephenson@mac.com>
Subject: Re: [linux-lvm] Performance penalty for 4k requests on thin provisioned volume
Date: Thu, 14 Sep 2017 11:37:21 +0200	[thread overview]
Message-ID: <c1d08569-dbaf-fffc-c3e5-dfe47513fa03@redhat.com> (raw)
In-Reply-To: <bb529703-849c-93ff-f40c-1de8a6f49ce6@redhat.com>

Dne 14.9.2017 v 11:00 Zdenek Kabelac napsal(a):
> Dne 14.9.2017 v 00:39 Dale Stephenson napsal(a):
>>
>>> On Sep 13, 2017, at 4:19 PM, Zdenek Kabelac <zkabelac@redhat.com> wrote:
>>>
>>
>> md127 is an 8-drive RAID 0
>>
>> As you can see, there’s no lvm striping; I rely on the software RAID 
>> underneath for that.  Both thick and thin lvols are on the same PV.
>>>
>>> SSD typically do needs ideally write 512K chunks.
>>
>> I could create the md to use 512k chunks for RAID 0, but I wouldn’t expect 
>> that to have any impact on a single threaded test using 4k request size.  Is 
>> there a hidden relationship that I’m unaware of?
> 
> 
> Yep - it seems the setup in this case is the best fit.

Sorry my typo here - is NOT ;)


Zdenek

  reply	other threads:[~2017-09-14  9:37 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-13 15:33 [linux-lvm] Performance penalty for 4k requests on thin provisioned volume Dale Stephenson
2017-09-13 20:19 ` Zdenek Kabelac
2017-09-13 22:39   ` Dale Stephenson
2017-09-14  9:00     ` Zdenek Kabelac
2017-09-14  9:37       ` Zdenek Kabelac [this message]
2017-09-14 10:52         ` Gionatan Danti
2017-09-14 10:57         ` Gionatan Danti
2017-09-14 11:13           ` Zdenek Kabelac
2017-09-14 14:32             ` Dale Stephenson
2017-09-14 15:25       ` Dale Stephenson

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