Re: ENOSPC on heterogeneous raid 0

[Hubert Kario <hka@qbs.com.pl>]

On Wednesday 08 of December 2010 22:53:25 William Sheffler wrote:
> Hello btrfs community.
>=20
> First off, thanks for all your hard work... I have been following
> btrfs with interest for several years now and very much look forward
> to the day it replaces ext4. The real killer feature (of btrfs
> specifically) for me is the ability to add *and remove* devices from =
a
> filesystem, as this allows rolling upgrades of my server's disks. I
> have a 16 port 3ware 1650SE on which I have a number of small raid
> units and it will be fantastic to be able to remove the oldest,
> upgrade, and add the new storage back. I had previously been using
> ZFS, but since ZFS doesn't allow removal of devices, this rolling
> upgrade strategy doesn't work.
>=20
> My question is this: can btrfs handle striping (raid 0) across
> heterogeneous devices? I seem to be losing any capacity on the larger
> disk beyond what is available on the smaller disk. I really hope ther=
e
> is some simple fix!

Yes, it can handle stripping over devices of different size, unfortunat=
ely=20
you're still limited to <size of smallest device>*<number of devices>

if you want to use all the available space use "-d single" when creatin=
g=20
volume

for details, read the recent thread "800GB free, but no space left"

--=20
Hubert Kario
QBS - Quality Business Software
02-656 Warszawa, ul. Ksawer=F3w 30/85
tel. +48 (22) 646-61-51, 646-74-24
www.qbs.com.pl
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