[gentoo-user] Re: SOLVED: Recover from LVM errors? (Was: Re: Help - system reboots while compiling)

[Remy Blank]

Boyd Stephen Smith Jr. wrote:
>> <troll>
>> ZFS?
>> </troll>
>
> You say troll, I say possibility; I'll certainly consider it.

Actually, I would be very interested in using ZFS for my data.

The "troll" was more about the fact that the ZFS license was explicitly
designed to be GPL-2 incompatible, hence preventing it from being
included into Linux (it would require a clean-room rewrite from the specs).

> However, the demos that I've seen about ZFS stress how easy it is to
> administer, and all the LVM-style features it has.  Personally,
> I've /very/ comfortable with LVM and am of the opinion that such features
> don't actually belong at the "filesystem" layer.

I haven't made the step to LVM and am still using a plain old RAID-1
mirror. I'm not that comfortable adding one more layer to the data path,
and one more difficulty in case of hard disk failure.

> I need to good general purpose filesystem, what matters most to be is:
> 1) Online growing of the filesystem, with LVM I use this a lot, I won't
> consider a filesystem I can't grow while it is in active use.
> 2) Journaling or other techniques (FFS from the *BSD world does something
> they don't like to call journaling) that reduce the frequency of full
> fscks.
> 3) All-round performance, and I don't mind it using extra CPU time or
> memory to make filesystem performance better, I have both to spare.
> 4) Storage savings (like tail packing or transparent compression)

I completely agree with 1) and 2), and 3) and 4) are nice to haves. What
I like in ZFS is the data integrity check, i.e. every block gets a
checksum, and it can auto-repair in a RAID-Z configuration, something
that RAID-1 cannot.

So I would add:
5) Reliable data integrity checks and self-healing capability.

-- Remy