Re: Feature requests: online backup - defrag - change RAID level

webmaster
2019-09-10T22:41:29Z

Quoting Andrei Borzenkov <arvidjaar@gmail.com>:

> 09.09.2019 20:11, webmaster@zedlx.com пишет:
> ...
>>>
>>> Forgot to mention this part.
>>>
>>> If your primary objective is to migrate your data to another device
>>> online (mounted, without unmount any of the fs).
>>
>> This is not the primary objective. The primary objective is to produce a
>> full, online, easy-to-use, robust backup. But let's say we need to do
>> migration...
>>>
>>> Then I could say, you can still add a new device, then remove the old
>>> device to do that.
>>
>> If the source filesystem already uses RAID1, then, yes, you could do it,
>
> You could do it with any profile.
>
>> but it would be too slow, it would need a lot of user intervention, so
>> many commands typed, so many ways to do it wrong, to make a mistake.
>>
>
> It requires exactly two commands - one to add new device, another to
> remove old device.
>

Yes, sorry I got a bit confused.

The point is that migration is not the objective. The objective could,
possibly, be restated as: make another copy of the filesystem.
Migration is something different.

>> Too cumbersome. Too wastefull of time and resources.
>>
>
> Do you mean your imaginary full backup will not read full filesystem?
> Otherwise how can it take less time and resources?

My imaginary full backup needs to read and write the entire filesystem.
It can't take less than that.