Re: [zfs-discuss] zvol wrapped in a vmdk by Virtual Box and double writes?

2012-11-21 Thread Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of Jim Klimov As for ZIL - even if it is used with the in-pool variant, I don't think your setup needs any extra steps to disable it (as Edward likes to suggest), and most other setups don't

Re: [zfs-discuss] zvol wrapped in a vmdk by Virtual Box and double writes?

2012-11-20 Thread Peter Tripp
Hi Nathan, You've misunderstood how the Zil works and why it reduces write latency for synchronous writes. Since you've partitioned a single SSD into two silces, one as pool storage and one as Zil for that pool, all sync writes will be 2X amplified. There's no way around it. ZFS will write

Re: [zfs-discuss] zvol wrapped in a vmdk by Virtual Box and double writes?

2012-11-20 Thread Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of Nathan Kroenert I chopped into a few slices - p0 (partition table), p1 128GB, p2 60gb. As part of my work, I have used it both as a RAW device (cxtxdxp1) and wrapped partition 1 with a

Re: [zfs-discuss] zvol wrapped in a vmdk by Virtual Box and double writes?

2012-11-20 Thread Fajar A. Nugraha
On Wed, Nov 21, 2012 at 12:07 AM, Edward Ned Harvey (opensolarisisdeadlongliveopensolaris) opensolarisisdeadlongliveopensola...@nedharvey.com wrote: Why are you parititoning, then creating zpool, The common case it's often because they use the disk for something else as well (e.g. OS), not only

Re: [zfs-discuss] zvol wrapped in a vmdk by Virtual Box and double writes?

2012-11-20 Thread nathan
Hi folks, some extra thoughts: 1. Don't question why. :) I'm playing and observing, so I ultimately know and understand the best way to do things! heh. 2. In fairness, asking why is entirely valid. ;) I'm not doing things to best practice just yet - I wanted the best performance for my VM's,

Re: [zfs-discuss] zvol wrapped in a vmdk by Virtual Box and double writes?

2012-11-20 Thread Jim Klimov
On 2012-11-21 03:21, nathan wrote: Overall, the pain of the doubling of bandwidth requirements seems like a big downer for *my* configuration, as I have just the one SSD, but I'll persist and see what I can get out of it. I might also speculate that for each rewritten block of userdata in the