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

btrfs for enterprise raid arrays

2009-04-02 Thread Erwin van Londen
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 class storage arrays. One exception to that was the ssd