Re: Quick EXT4 discard question

[Tao Ma <tm@tao.ma>]

On 04/22/2011 03:44 PM, Lukas Czerner wrote:
> On Fri, 22 Apr 2011, Tao Ma wrote:
> 
>> On 04/22/2011 10:44 AM, Keith Mannthey wrote:
>>> On Fri, 2011-04-22 at 10:27 +0800, Tao Ma wrote:
>>>> On 04/22/2011 08:45 AM, Keith Mannthey wrote:
>>>>> Hello,
>>>>>   I am using some Intel SSD drives with 2.6.38.2. 
>>>>>
>>>>>
>>>>> /proc/scsi/scsi identifies them as: 
>>>>>
>>>>> "
>>>>> Host: scsi4 Channel: 00 Id: 04 Lun: 00
>>>>>   Vendor: ATA      Model: INTEL SSDSA2M080 Rev: 02M3
>>>>>   Type:   Direct-Access                    ANSI  SCSI revision: 05
>>>>> "
>>>>>
>>>>> Sometimes I am see the following messages that indicate discard is
>>>>> disabled during runtime:  
>>>>>
>>>>> Relevant dmesg:
>>>>>
>>>>> ...
>>>>> EXT4-fs (sdw): mounted filesystem with ordered data mode. Opts: nobarrier,discard
>>>>> EXT4...... 
>>>>>
>>>>> .... (some time later) 
>>>>>
>>>>> EXT4-fs warning (device sdw): release_blocks_on_commit:2672: discard not supported, disabling
>>>>> EXT4-fs warning (device sds): release_blocks_on_commit:2672: discard not supported, disabling
>>>>> EXT4-fs warning (device sdt): release_blocks_on_commit:2672: discard not supported, disabling
>>>>> EXT4-fs warning (device sdu): release_blocks_on_commit:2672: discard not supported, disabling
>>>>> EXT4-fs warning (device sdv): release_blocks_on_commit:2672: discard not supported, disabling
>>>> Please check whether your ssd works with discard or whether your ssd
>>>> firmware has the ability to do so.
>>>> I used an SSDSA2M160(I guess you are using the same type as me except
>>>> the volume size is 80g, but you have to find it out from intel side) and
>>>> after I upgraded my firmware to the new version(you can download it from
>>>> intel site), it supports discard now.
>>>
>>>
>>> Firmware is up to date as of a few weeks ago.  It is 02M3 which still
>>> looks to be the current version. 
>> ok...
>> So please check whether your device supports discard or not.
>> Intel has a tool named Intel SSD Toolbox, and it can check the status of
>> your ssd, but the bad thing is that it seems to only have a windows
>> version...
> 
> Actually you can query that with hdparm -I /path/to/the/device and you
> should see something like
> 
> *   Data Set Management TRIM supported
> 
> in the output.
oh, yes, I just tried the latest hdparm(9.37) and it does support trim
detection now! Thanks for the hint.
So I am still living in the rhel5 period. :(

Regards,
Tao