cpio to ext4 seems much slower than to ext2, ext3 or xfs

[Dennis J.]

On 11/12/2009 05:59 PM, Eric Sandeen wrote:
> Dennis J. wrote:
>> On 11/12/2009 04:03 PM, Eric Sandeen wrote:
>>> Richard W.M. Jones wrote:
>
> ...
>
>>>> I'd like to repeat my proviso: I think this test is meaningless for
>>>> most users.
>>>
>>> Until users have 8TB raids at home, which is not really that far off ...
>>
>> Let's hope btrfs is production ready before then because extX doesn't
>> look like a fitting filesystem for such big drives due their lack of
>> online fsck.
>
> ext4's fsck is much faster than ext3's, and xfs's repair tool is also
> pretty speedy.
>
> Both are offline, but so far online fsck for btrfs is just a goal, no
> (released, anyway) code yet AFAIK.

Isn't the speed improvement of ext4 achieved by not dealing with empty 
extends/blocks? If so that wouldn't help you much if those 8TB are really 
used. But even a speedy fsck is going to take longer and longer as 
filesystem size grows which is why I believe we will soon reach a point 
were offline-fsck simply isn't a viable option anymore.
I have a 30TB storage system that I chopped into ten individual volumes 
because current filesystems don't really make creating a single 30TB fs a 
wise choice even though I'd like to be able to do that.

Regards,
   Dennis