Beginners questions

Cassandra von Ahrcanburg proudmouse at tlink.de
Sun Dec 1 08:44:53 PST 2013


On Fri, 29 Nov 2013 15:26:51 -0500
Nikolai Lifanov <lifanov at mail.lifanov.com> wrote:

> You will have a much better experience adding disks to HAMMER than
> ZFS. HAMMER relies on hardware raid for redundancy, and you can just
> add "hammer volume-add" new disks and it will concatenate them.
> With ZFS, you have to add disks one leg at a time. So, with a
> triple-parity raid10 with 2 legs (6 disks), you will have to add 3
> disks at a time. To a raidz2 with 8 disks, you will need to add 8 at
> a time... You get the picture.

I wasn't going to use a hardware RAID at all. A friend of mine works
for a company that builds and installs servers and workstations in all
sorts of firms. They often use RAID controllers and judging by the
amount of failures they encounter (and I don't even think he told me
all the stories there are to tell), I don't see any real advantages in
hardware RAID. Quite often I get to hear stories about a disc dying and
the RAID controller refusing to accept a replacement and rebuild the
RAID, although the drive is of same make and model. I'll give software
RAID a chance.

I wasn't going to create a RAID10 with parity. This is cold storage and
offsite backups exist. I have been using "simple" UFS up until now.

I wanted to make a raidz2, which is basicly like a RAID6 (striping,
double-parity, no mirroring). The minimum starter consists of 4 HDs.
This should be easier to grow.

When using FreeBSD this can be setup with ZFS alone. AFAIK HAMMER will
need the LVM for the volumes. Can I still grow the RAID as I need it
(one disc at a time)?

Kind regards,
Cassi




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