From: Eric Sandeen <sandeen@redhat.com>
Subject: Re: problem(?) in ext4 or mke2fs
Date: Sun, 03 Apr 2011 11:56:32 -0700
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To: Zeev Tarantov <zeev.tarantov@gmail.com>
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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.