Re: Facing the End ;-)

"Ingo Weinhold" <bonefish-CFLBMwTPW48UNGrzBIF7/[email protected]>
Newsgroups gmane.os.openbeos.storage
Message-ID <31203116717-BeMail@graete>
> 
> "Ingo Weinhold" <bonefish-CFLBMwTPW48UNGrzBIF7/[email protected]> wrote:
> [...]
> > on can tell, what extactly is supported. Regaring the FS flags 
> > mentioned in my previous mail, I will add a `fs=5Fflags' field to 
> > extended=5Fpartition=5Finfo, that will look the same as fs=
> > 5Finfo::flags. 
> > (If 
> > also a free=5Fblocks would be added, then one should have enough 
> > information for resizing of partitions.)
> 
> That doesn't have to be the case; in the end, the file system itself 
> must be bothered with the question of the overhead of a partition 
> resize operation - only the file system can now if it needs more 
> space 
> to i.e. store the (now) fragmented file or something like this.

It could defragment the partition before. :-P
Honestly, I see the problem, but without knowing in advance how small a 
FS can become, it is very ugly to implement a GUI to let the user do 
the resizing.

Maybe a `free_blocks' field is not what I'm thinking of, but rather a 
`minimal_fs_size'. I suspect most FSs can simply set that to the used 
size -- it least, if they are able to defragment or whatever is 
necessary to not use more space when being shrunk -- others may add a 
safety margin, that they can estimate best.

> Of course, we could just have a generic safety margin that would be 
> suitable for all file systems, like there needs to be at least 3% 
> free 
> space in the new volume, or something like that.

That's hard to do well in general. 3% doesn't sound much, but for a 35 
GB disk it is 1+ GB, which I find not acceptable as granularity.

CU, Ingo
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.