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From: Kapil Upadhayay <>
To: Roberto Fastec <>,
	LVM general discussion and development <>
Cc: "" <>,
	Mitta Sai Chaithanya <>
Subject: Re: [linux-lvm] LVM2 : performance drop even after deleting the snapshot
Date: Mon, 17 Oct 2022 05:01:27 +0000	[thread overview]
Message-ID: <HK0P153MB03244D79ED10AEAC52F60EF6C2299@HK0P153MB0324.APCP153.PROD.OUTLOOK.COM> (raw)
In-Reply-To: <>

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The thin volume was created on a block disk provided by Microsoft Azure Managed disk provisioned on premium SSD which is ready to be used in production environment. The disk can provide sustained Max IOPs at 5000.

Kapil Upadhayay.

From: Roberto Fastec <>
Sent: Saturday, October 15, 2022 1:58 AM
To: LVM general discussion and development <>
Cc: Kapil Upadhayay <>; Mitta Sai Chaithanya <>;
Subject: [EXTERNAL] Re: [linux-lvm] LVM2 : performance drop even after deleting the snapshot

Some people who received this message don't often get email from<>. Learn why this is important<>
forget SSDs with LVM unless of enterprise level
especially if you are going to use/implement the thin provisioning
How to identify an SSD of enterprise level:
it costs from 1,00 euro per gigabyte up to 1,50 euro per gigabyte
Kind regards
Roberto Gini
Technical Manager @<>

Ottieni BlueMail per Android<>
Il giorno 14 ott 2022, alle ore 21:50, Roger Heflin <<>> ha scritto:

What is the underlying disk hardware you are running this on?
virtual, spinning, ssd, nvme?

On Thu, Oct 13, 2022 at 2:01 AM Pawan Sharma <<>> wrote:

 adding this to lvm-devel mailing list also.



 From: Pawan Sharma
 Sent: Wednesday, October 12, 2022 10:42 PM
 To:<> <<>>
 Cc: Mitta Sai Chaithanya <<>>; Kapil Upadhayay <<>>
 Subject: LVM2 : performance drop even after deleting the snapshot

 Hi Everyone,

 We are evaluating lvm2 snapshots and doing performance testing on it. This is what we are doing :

 dump some data to lvm2 volume (using fio)
 take the snapshot
 delete the snapshot (no IOs anywhere after creating the snapshot)
 run the fio on lvm2 volume

 Here as you can see, we are just creating the snapshot and immediately deleting it. There are no IOs to the main volume or anywhere. When we run the fio after this (step 4) and we see around 50% drop in performance with reference to the number we get in step 1.

 It is expected to see a performance drop if there is a snapshot because of the COW. But here we deleted the snapshot, and it is not referring to any data also. We should not see any performance drop here.

 Could someone please help me understand this behavior. Why are we seeing the performance drop in this case? It seems like we deleted the snapshot but still it is not deleted, and we are paying the COW penalty.

 System Info:

 OS : ubuntu 18.04
 Kernel : 5.4.0

 # lvm version
   LVM version:     2.02.176(2) (2017-11-03)
   Library version: 1.02.145 (2017-11-03)
   Driver version:  4.41.0

 We also tried on latest ubuntu with newer version of LVM. We got the same behavior.

 Any help/pointers would be appreciated. Thanks in advance.



 linux-lvm mailing list<><>
 read the LVM HOW-TO at<>/


linux-lvm mailing list<><>
read the LVM HOW-TO at<>/

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linux-lvm mailing list
read the LVM HOW-TO at

  reply	other threads:[~2022-10-17  7:31 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-12 17:12 [linux-lvm] LVM2 : performance drop even after deleting the snapshot Pawan Sharma
2022-10-13  6:53 ` Pawan Sharma
2022-10-13 10:50   ` Zdenek Kabelac
2022-10-14 19:31     ` [linux-lvm] [EXTERNAL] " Mitta Sai Chaithanya
2022-10-17 13:10       ` Zdenek Kabelac
2022-10-17 13:41         ` Erwin van Londen
2022-10-20 18:19           ` Zdenek Kabelac
2022-10-18  3:33         ` Pawan Sharma
2022-10-18 11:15           ` Zdenek Kabelac
2022-10-14 19:50   ` [linux-lvm] " Roger Heflin
2022-10-14 20:28     ` Roberto Fastec
2022-10-17  5:01       ` Kapil Upadhayay [this message]
2022-10-17 15:16       ` Demi Marie Obenour

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