Re: [Fstransform-devel] preservation of hard links

[Massimiliano G. <mas...@gm...>]

On 10/29/14 23:58, Olaf Leidinger wrote:
> On 10/29/14 23:36, Massimiliano Ghilardi wrote:
>> Yes, it preserves hard links. In order to do that, it keeps an
>> in-memory cache of hard links found so far. If the cache gets larger
>> than available RAM, it starts swapping to disk and you're in trouble:
>> it will take ages to finish, or, if it runs out of swap space, it
>> will crash.
>
> Actually, I can't really guess how many hard links are there on this
> partition. The server has 8 GiB of RAM + 8 GiB of swap... I'll try and
> report back how it worked.
>
> Best,
> Olaf

Hello Olaf,

I added support for disk-based inode cache in the latest version of 
fstranform. While not released yet, initial tests are successful.

You can download it from https://github.com/cosmos72/fstransform
either with the 'download ZIP' button on the right, or by cloning the 
GIT repository.

To actually enable the disk-based inode cache, you must add the option
--inode-cache="DIR"
to fsmove. If you use the main fstransform script, the option becomes
--opts-fsmove="--inode-cache=DIR"

where DIR is be the path of a non-existing directory (fsmove will create 
it) - it can also be inside the filesystem to be transformed.

Such directory will be filled with one soft-link per group of hard-links 
pointing to the same file, so it must be inside a filesystem with plenty 
of available inodes ("df -i" is your friend).


Best regards,

Max