Re: btrfs for enterprise raid arrays

2009-04-03 Thread Sander
Dear Erwin, Erwin van Londen wrote (ao): Another thing is that some arrays have the capability to thin-provision volumes. In the back-end on the physical layer the array configures, let say, a 1 TB volume and virtually provisions 5TB to the host. On writes it dynamically allocates more pages

Re: btrfs for enterprise raid arrays

2009-04-03 Thread David Woodhouse
On Fri, 2009-04-03 at 12:43 +0100, Ric Wheeler wrote: New firmware/microcode versions are able to reclaim that space if it sees a certain number of consecutive zero's and will reclaim that space to the volume pool. Are there any thoughts on writing a low-priority tread that zeros out

Re: btrfs for enterprise raid arrays

2009-04-03 Thread Chris Mason
On Thu, 2009-04-02 at 21:34 -0700, Erwin van Londen wrote: Dear all, While going through the archived mailing list and crawling along the wiki I didn't find any clues if there would be any optimizations in Btrfs to make efficient use of functions and features that today exist on enterprise

Re: btrfs for enterprise raid arrays

2009-04-03 Thread Matthew Wilcox
On Fri, Apr 03, 2009 at 12:58:00PM +0100, David Woodhouse wrote: On Fri, 2009-04-03 at 12:43 +0100, Ric Wheeler wrote: New firmware/microcode versions are able to reclaim that space if it sees a certain number of consecutive zero's and will reclaim that space to the volume pool. Are

Re: btrfs for enterprise raid arrays

2009-04-03 Thread James Bottomley
On Fri, 2009-04-03 at 06:27 -0700, Matthew Wilcox wrote: On Fri, Apr 03, 2009 at 12:58:00PM +0100, David Woodhouse wrote: On Fri, 2009-04-03 at 12:43 +0100, Ric Wheeler wrote: New firmware/microcode versions are able to reclaim that space if it sees a certain number of consecutive

Re: btrfs for enterprise raid arrays

2009-04-03 Thread James Bottomley
On Fri, 2009-04-03 at 07:43 -0400, Ric Wheeler wrote: Erwin van Londen wrote: Another thing is that some arrays have the capability to thin-provision volumes. In the back-end on the physical layer the array configures, let say, a 1 TB volume and virtually provisions 5TB to the host. On