From: Andreas Dilger <adilger@whamcloud.com>
Subject: Re: problem(?) in ext4 or mke2fs
Date: Sun, 3 Apr 2011 14:40:43 -1000
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Cc: Zeev Tarantov <zeev.tarantov@gmail.com>,
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To: Eric Sandeen <sandeen@redhat.com>
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Cheers, Andreas

On 2011-04-03, at 8:56 AM, Eric Sandeen <sandeen@redhat.com> wrote:

> On 4/3/11 11:52 AM, Zeev Tarantov wrote:
>> On Sun, Apr 3, 2011 at 21:40, Eric Sandeen <sandeen@redhat.com> wrote:
> 
> ...
> 
>>> What does
>>> 
>>> # blockdev --getiomin --getioopt /dev/<yourdevice>
>>> 
>>> say for your device?
>> 
>> get logical block (sector) size: 4096
>> get physical block (sector) size: 4096
>> get minimum I/O size: 4096
>> get optimal I/O size: 4096
>> get alignment offset in bytes: 0
>> get max sectors per request: 255
>> get blocksize: 4096
>> get readahead: 256
>> 
>>> The device may be reporting odd values, but mke2fs probably
>>> should be smart enough not to set block-sized stripe unit and width...
>> 
>> If the filesystem created with the default options is slow or has
>> higher cpu usage, it should be changed.
> 
> I agree.  For actual striped storage, this makes it faster, but this
> case is a problem; block-sized stripe width is never going to be good.
> What device is this, exactly?
> 
> -Eric (losing my free airport wifi in about 8 minutes, so I may have
> to continue this later...!)
> 
>>> -Eric
>> 
>> -Z.T.
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