[volunteergrid2-l] Redundancy

[erpo41 at gmail.com]

Hi,

Thought you might like another data point. For tahoe-lafs, a single plain
disk is good enough for the reasons Shawn gave.

For your own personal data, priority 1 is backing up. If you've got two or
more disks and you're thinking about making a RAID set or using ZFS or
btrfs, just don't. Take out one of the disks, put it in an external
enclosure, and back up to it. With RAID/ZFS/btrfs, if you delete a file,
the underlying software will happily delete it from all of the disks. If
your filesystem gets corrupted to the point that the driver can't make
heads or tails of it, your files are gone unless you have a backup.

RAID: Useful, but not as useful as you think. It can protect against whole
disk failures, but there are so many ways your data could be silently
corrupted even in a RAID setup. RAID is a tool to improve uptime, not to
replace backing up.

ZFS/btrfs: A good idea on paper. The question is: what is the quality of
the filesystem driver? On solaris, ZFS is supposed to be pretty good. On
FreeBSD it's supposedly ok. I've worked on zfs-fuse (the Linux port of ZFS)
and I can tell you from first hand experience that sometimes it loses your
volumes. Boom. Just gone. That's supposedly impossible with ZFS, but errors
and bugs do crop up because the filesystem driver just isn't mature.

I don't know about you, but what I want as far as a filesystem doesn't
exist yet. Personaly, I use an ext4 filesystem on RAID6. Then I back up my
important data onto it using deja-dup.

Hope that helps,
Eric


On Mon, Apr 23, 2012 at 11:24 AM, Samuel Willcocks
<samuel at willcockses.com>wrote:

>  Hi list, one of the new lurkers here.
> I'm looking into options for providing redundancy - what do you grid
> members use? Hard/software RAID? ZFS? I have looked briefly into RAID
> cards, can you recommend any over others for reliability/compatibility with
> Linux/etc?
> Cheers,
> Sam
>
>
> _______________________________________________
> volunteergrid2-l mailing list
> volunteergrid2-l at tahoe-lafs.org
> https://tahoe-lafs.org/cgi-bin/mailman/listinfo/volunteergrid2-l
> http://bigpig.org/twiki/bin/view/Main/WebHome
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://tahoe-lafs.org/cgi-bin/mailman/private/volunteergrid2-l/attachments/20120423/69868438/attachment.html>