[Mageia-dev] time to switch from raw partitions to lvm?

[Thomas Lottmann]

Le 21/02/2011 10:36, Thierry Vignaud a écrit :
> On 21 February 2011 08:51, P. Christeas<p_christ at hol.gr>  wrote:
>>> What do you think about switching from defaulting to installing on raw
>>> partitions to lvm
>>> installing on LVs like fedora does ?
>>
>> I vote against that. (=to be enabled by default)
>>
>> LVM is fine for "enterprise" setups, or better, installations where the
>> (expert) admin will need to resize/move partitions in the future. But, for
>> simple machines/users, the complexity of having LVM is IMHO not worth it.
>>
>> (remember also that on all *nix OSes, you can just add a partition, move some
>> files like /usr/share/doc into it and then mount it on /usr/share/doc, thus
>> freeing /usr of some space. No LVM, no virtualization, no ZFS required)
>
> It's not as easy as LVM (need to use a partitionner).
> Diskdrake and the like will force you to umount the partitions to resize
> which may needs to boot on a rescue CD (eg for resizing / fs)
> It may not be possible ie:
>
> - you already have 4 primary partitions and none of them is an extended one.
>
> - If you've a small 8Go partition at start of the disk followed by one
> To partition
>    and you want to increase the first one, you're screwed without LVM
>    With LVM, you can just got some free space from anywhere (even another disk)
>
> What's more, one gains many features:
>
> - snapshots (yes snapshots for sql db backups are not for end users) but still
>    usefull for saving the whole system at one fixed time
>
> - you can extend some filesystems from space from other disks
>
> - it's easier to add space where needed when defaults partitions sizing proved
>    to be altered after some usage
>
> - one can live resize (w/o umouting/remounting)
>
> - one can use snapshots in order to rollback dangerous update
>    (eg: for trying initscript ->  systemd switch, ...)
>
> I think it brings many usefull features.
> Those who don't want LVM could still do manual partitionning.

I am still not convinced of how easy this can be. For having attempted 
to manage (and learn) how to manage LVM partitons with CentOS, it is 
quite complicated. So it certainly has many advantages, but I'm awaiting 
an intuitive disk manager like Diskdrake to manage this stuff without 
the need of preliminary knowledge.