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From: Marian Csontos <mcsontos@redhat.com>
To: LVM general discussion and development <linux-lvm@redhat.com>
Cc: Zdenek Kabelac <zkabelac@redhat.com>, Micky <mickylmartin@gmail.com>
Subject: Re: [linux-lvm] Very slow i/o after snapshotting
Date: Tue, 09 Jul 2013 14:19:16 +0200	[thread overview]
Message-ID: <51DBFFC4.6070501@redhat.com> (raw)
In-Reply-To: <CAKAA-nnZUvBuHmRaD9mn19gC51GfiihmweaJXTDRfRN92mstag@mail.gmail.com>

On 07/09/2013 01:51 PM, Micky wrote:
>> Is this supposed to be a bug report ?
>
> Sorry for bashing the info. I was just answering the questions. LOL!
>
>> So far I've no idea about disks/tables in use, system/kernel in use, lvm
>> version in use....
>
> RHEL 6.4 kernel-2.6.32-358.el6 (also tested with self compiled 3.8)
> lvm2-2.02.98-9.el6.x86_64
> Disk on external mega raid controller with ext4

How does it perform without snapshot? I have seen a sluggish RAID array 
when run out of battery.

Is there a reason to use that big chunks?
If the origin is seeing a lot of small dispersed writes using big chunk 
may multiply it manyfold (actually worst case 128-times: every 4k write 
generating 512k read from origin and then written to snapshot.)

-- Marian

> Running Xen hypervisor but tested without it as well
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>

  reply	other threads:[~2013-07-09 12:19 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-09  1:37 [linux-lvm] Very slow i/o after snapshotting Micky
2013-07-09  5:01 ` Marian Csontos
2013-07-09  8:26   ` Micky
2013-07-09  9:54 ` Zdenek Kabelac
2013-07-09 11:51   ` Micky
2013-07-09 12:19     ` Marian Csontos [this message]
2013-07-09 12:43       ` Micky
2013-07-09 13:20         ` Zdenek Kabelac
2013-07-09 14:04           ` Micky
2013-07-09 14:18             ` Zdenek Kabelac
2013-07-09 14:57               ` Micky
2013-07-09 15:14                 ` Zdenek Kabelac
2013-07-09 15:26                   ` Micky
2013-07-09 15:26                 ` Marian Csontos
2013-07-09 15:35                   ` Micky
2013-07-09 15:39                     ` Micky
2013-07-09 18:47                       ` Zdenek Kabelac
2013-07-09 23:15                         ` Micky
2013-07-09 23:29                           ` Micky
2013-07-09 17:59           ` matthew patton
2013-07-09 18:42             ` Zdenek Kabelac

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