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From: Alexandre DERUMIER <aderumier@odiso.com>
To: ronnie sahlberg <ronniesahlberg@gmail.com>
Cc: kvm@vger.kernel.org
Subject: Re: block device type supporting trim or scsi unmap ?
Date: Thu, 10 May 2012 22:42:02 +0200 (CEST)	[thread overview]
Message-ID: <d28ee1be-3c13-4bca-885d-5ff6699b5940@mailpro> (raw)
In-Reply-To: <CAN05THQD7hvqqe1uXaR3387H_MqHpOhg-miGNyhDJnQQ0zrgFw@mail.gmail.com>

>>Guess it depends on how recent kernel your guest runs. 
>>If you present it as a SCSI disk to the guest, then I have 
>>successfully had Linux Mint 12 guests do UNMAP when accessing /dev/sd* 
>>from within the guest. 

Ok, thanks for the info, i'll try it !


----- Mail original ----- 

De: "ronnie sahlberg" <ronniesahlberg@gmail.com> 
À: "Alexandre DERUMIER" <aderumier@odiso.com> 
Cc: kvm@vger.kernel.org 
Envoyé: Jeudi 10 Mai 2012 14:36:38 
Objet: Re: block device type supporting trim or scsi unmap ? 

On Thu, May 10, 2012 at 10:28 PM, Alexandre DERUMIER 
<aderumier@odiso.com> wrote: 
>>>iscsi supports it too but it requires that your iscsi target supports 
>>>these opcodes, and that the filesystem/storage behind it supports it 
>>>too. 
>>>TGTD with EXT4 and a suitable storage device should do the trick. 
> 
> I'm using a iscsi solaris target, with scsi UNMAP support. 
> Drives also support scsi unmap in raid (ocz talos hdd). 
> I'm using direct lun access from host to guest. 
> 
> 
> But my question was, which block device inside guests have trim or scsi unmap implemention ? 
> 
> 

Guess it depends on how recent kernel your guest runs. 
If you present it as a SCSI disk to the guest, then I have 
successfully had Linux Mint 12 guests do UNMAP when accessing /dev/sd* 
from within the guest. 


If you present the device as a SCSI disk to the guest, you use a 
recent 3.x linux kernel for the guest and EXT4 as the filesystem 
I guess it should work. 


Dont know about status for IDE emulation. 

regards 
ronnie sahlberg 



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	Alexandre D erumier 
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      reply	other threads:[~2012-05-10 20:42 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <4d1098b7-0c3e-4253-9381-be021467b76e@mailpro>
2012-05-10 10:19 ` block device type supporting trim or scsi unmap ? Alexandre DERUMIER
2012-05-10 10:27   ` ronnie sahlberg
2012-05-10 12:28     ` Alexandre DERUMIER
2012-05-10 12:36       ` ronnie sahlberg
2012-05-10 20:42         ` Alexandre DERUMIER [this message]

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