Re: [zfs-discuss] Deduplication Memory Requirements

On Mon, May 9, 2011 at 2:11 AM, Evaldas Auryla wrote: > On 05/ 6/11 07:21 PM, Brandon High wrote: > >> On Fri, May 6, 2011 at 9:15 AM, Ray Van Dolson >> wrote: >> >> We use dedupe on our VMware datastores and typically see 50% savings, >>> often times more. We do of course keep "like" VM's on t

Re: [zfs-discuss] Deduplication Memory Requirements

On 05/ 6/11 07:21 PM, Brandon High wrote: On Fri, May 6, 2011 at 9:15 AM, Ray Van Dolson wrote: We use dedupe on our VMware datastores and typically see 50% savings, often times more. We do of course keep "like" VM's on the same volume I think NetApp uses 4k blocks by default, so the block s

Re: [zfs-discuss] Deduplication Memory Requirements

On Fri, May 6, 2011 at 9:15 AM, Ray Van Dolson wrote: > We use dedupe on our VMware datastores and typically see 50% savings, > often times more.  We do of course keep "like" VM's on the same volume I think NetApp uses 4k blocks by default, so the block size and alignment should match up for mos

Re: [zfs-discuss] Deduplication Memory Requirements

On Wed, May 04, 2011 at 08:49:03PM -0700, Edward Ned Harvey wrote: > > From: Tim Cook [mailto:t...@cook.ms] > > > > That's patently false.  VM images are the absolute best use-case for dedup > > outside of backup workloads.  I'm not sure who told you/where you got the > > idea that VM images are n

Re: [zfs-discuss] Deduplication Memory Requirements

On Thu, May 5, 2011 at 8:50 PM, Edward Ned Harvey wrote: > If you have to use the 4k recordsize, it is likely to consume 32x more > memory than the default 128k recordsize of ZFS.  At this rate, it becomes > increasingly difficult to get a justification to enable the dedup.  But it's > certainly p

Re: [zfs-discuss] Deduplication Memory Requirements

> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Edward Ned Harvey > > If you have to use the 4k recordsize, it is likely to consume 32x more > memory than the default 128k recordsize of ZFS. At this rate, it becomes > increasingly difficult

Re: [zfs-discuss] Deduplication Memory Requirements

> From: Brandon High [mailto:bh...@freaks.com] > > On Wed, May 4, 2011 at 8:23 PM, Edward Ned Harvey > wrote: > > Generally speaking, dedup doesn't work on VM images.  (Same is true for > ZFS > > or netapp or anything else.)  Because the VM images are all going to have > > their own filesystems i

Re: [zfs-discuss] Deduplication Memory Requirements

On May 5, 2011, at 6:02 AM, Edward Ned Harvey wrote: > Is this a zfs discussion list, or a nexenta sales & promotion list? Obviously, this is a Nextenta sales & promotion list. And Oracle. And OSX. And BSD. And Linux. And anyone who needs help or can offer help with ZFS technology :-) This list ha

Re: [zfs-discuss] Deduplication Memory Requirements

On May 5, 2011, at 2:58 PM, Brandon High wrote: > On Wed, May 4, 2011 at 8:23 PM, Edward Ned Harvey > >> Or if you're intimately familiar with both the guest & host filesystems, and >> you choose blocksizes carefully to make them align. But that seems >> complicated and likely to fail. > > Using

Re: [zfs-discuss] Deduplication Memory Requirements

On Wed, May 4, 2011 at 8:23 PM, Edward Ned Harvey wrote: > Generally speaking, dedup doesn't work on VM images.  (Same is true for ZFS > or netapp or anything else.)  Because the VM images are all going to have > their own filesystems internally with whatever blocksize is relevant to the > guest O

Re: [zfs-discuss] Deduplication Memory Requirements

We have customers using dedup with lots of vm images... in one extreme case they are getting dedup ratios of over 200:1! You don't need dedup or sparse files for zero filling. Simple zle compression will eliminate those for you far more efficiently and without needing massive amounts of ram.

Re: [zfs-discuss] Deduplication Memory Requirements

I assume you're talking about a situation where there is an initial VM image, and then to clone the machine, the customers copy the VM, correct? If that is correct, have you considered ZFS cloning instead? When I said dedup wasn't good for VM's, what I'm talking about is: If there is data in

Re: [zfs-discuss] Deduplication Memory Requirements

On Thu, 2011-05-05 at 09:02 -0400, Edward Ned Harvey wrote: > > From: Garrett D'Amore [mailto:garr...@nexenta.com] > > > > We have customers using dedup with lots of vm images... in one extreme > > case they are getting dedup ratios of over 200:1! > > I assume you're talking about a situation whe

Re: [zfs-discuss] Deduplication Memory Requirements

Hi, On 05/ 5/11 03:02 PM, Edward Ned Harvey wrote: From: Garrett D'Amore [mailto:garr...@nexenta.com] We have customers using dedup with lots of vm images... in one extreme case they are getting dedup ratios of over 200:1! I assume you're talking about a situation where there is an initial VM

Re: [zfs-discuss] Deduplication Memory Requirements

> From: Garrett D'Amore [mailto:garr...@nexenta.com] > > We have customers using dedup with lots of vm images... in one extreme > case they are getting dedup ratios of over 200:1! I assume you're talking about a situation where there is an initial VM image, and then to clone the machine, the cus

Re: [zfs-discuss] Deduplication Memory Requirements

> From: Tim Cook [mailto:t...@cook.ms] > > That's patently false.  VM images are the absolute best use-case for dedup > outside of backup workloads.  I'm not sure who told you/where you got the > idea that VM images are not ripe for dedup, but it's wrong. Well, I got that idea from this list. I

Re: [zfs-discuss] Deduplication Memory Requirements

> From: Tim Cook [mailto:t...@cook.ms] > > > ZFS's problem is that it needs ALL the resouces for EACH pool ALL the > > time, and can't really share them well if it expects to keep performance > > from tanking... (no pun intended) > That's true, but on the flipside, if you don't have adequate resou

Re: [zfs-discuss] Deduplication Memory Requirements

On Wed, May 4, 2011 at 10:23 PM, Edward Ned Harvey < opensolarisisdeadlongliveopensola...@nedharvey.com> wrote: > > From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > > boun...@opensolaris.org] On Behalf Of Ray Van Dolson > > > > Are any of you out there using dedupe ZFS file systems

Re: [zfs-discuss] Deduplication Memory Requirements

On Wed, May 4, 2011 at 10:15 PM, Edward Ned Harvey < opensolarisisdeadlongliveopensola...@nedharvey.com> wrote: > > From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > > boun...@opensolaris.org] On Behalf Of Erik Trimble > > > > ZFS's problem is that it needs ALL the resouces for EACH

Re: [zfs-discuss] Deduplication Memory Requirements

> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Ray Van Dolson > > Are any of you out there using dedupe ZFS file systems to store VMware > VMDK (or any VM tech. really)? Curious what recordsize you use and > what your hardware specs / exp

Re: [zfs-discuss] Deduplication Memory Requirements

> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Erik Trimble > > ZFS's problem is that it needs ALL the resouces for EACH pool ALL the > time, and can't really share them well if it expects to keep performance > from tanking... (no pun inten

Re: [zfs-discuss] Deduplication Memory Requirements

On 5/4/2011 5:11 PM, Brandon High wrote: On Wed, May 4, 2011 at 4:36 PM, Erik Trimble wrote: If so, I'm almost certain NetApp is doing post-write dedup. That way, the strictly controlled max FlexVol size helps with keeping the resource limits down, as it will be able to round-robin the post-wr

Re: [zfs-discuss] Deduplication Memory Requirements

On Wed, May 4, 2011 at 6:51 PM, Erik Trimble wrote: > On 5/4/2011 4:44 PM, Tim Cook wrote: > > > > On Wed, May 4, 2011 at 6:36 PM, Erik Trimble wrote: > >> On 5/4/2011 4:14 PM, Ray Van Dolson wrote: >> >>> On Wed, May 04, 2011 at 02:55:55PM -0700, Brandon High wrote: >>> On Wed, May 4, 2011

Re: [zfs-discuss] Deduplication Memory Requirements

On Wed, May 4, 2011 at 4:36 PM, Erik Trimble wrote: > If so, I'm almost certain NetApp is doing post-write dedup.  That way, the > strictly controlled max FlexVol size helps with keeping the resource limits > down, as it will be able to round-robin the post-write dedup to each FlexVol > in turn.

Re: [zfs-discuss] Deduplication Memory Requirements

On Wed, May 04, 2011 at 04:51:36PM -0700, Erik Trimble wrote: > On 5/4/2011 4:44 PM, Tim Cook wrote: > > > > On Wed, May 4, 2011 at 6:36 PM, Erik Trimble > wrote: > > On 5/4/2011 4:14 PM, Ray Van Dolson wrote: > > On Wed, May 04, 2011 at 02:55:55PM -0700, Brandon H

Re: [zfs-discuss] Deduplication Memory Requirements

On 5/4/2011 4:44 PM, Tim Cook wrote: On Wed, May 4, 2011 at 6:36 PM, Erik Trimble > wrote: On 5/4/2011 4:14 PM, Ray Van Dolson wrote: On Wed, May 04, 2011 at 02:55:55PM -0700, Brandon High wrote: On Wed, May 4, 2011 at 12:29 PM, Erik

Re: [zfs-discuss] Deduplication Memory Requirements

On 5/4/2011 4:17 PM, Ray Van Dolson wrote: On Wed, May 04, 2011 at 03:49:12PM -0700, Erik Trimble wrote: On 5/4/2011 2:54 PM, Ray Van Dolson wrote: On Wed, May 04, 2011 at 12:29:06PM -0700, Erik Trimble wrote: (2) Block size: a 4k block size will yield better dedup than a 128k block size, pre

Re: [zfs-discuss] Deduplication Memory Requirements

On Wed, May 4, 2011 at 6:36 PM, Erik Trimble wrote: > On 5/4/2011 4:14 PM, Ray Van Dolson wrote: > >> On Wed, May 04, 2011 at 02:55:55PM -0700, Brandon High wrote: >> >>> On Wed, May 4, 2011 at 12:29 PM, Erik Trimble >>> wrote: >>> I suspect that NetApp does the following to limit the

Re: [zfs-discuss] Deduplication Memory Requirements

On 5/4/2011 4:14 PM, Ray Van Dolson wrote: On Wed, May 04, 2011 at 02:55:55PM -0700, Brandon High wrote: On Wed, May 4, 2011 at 12:29 PM, Erik Trimble wrote: I suspect that NetApp does the following to limit their resource usage: they presume the presence of some sort of cache that c

Re: [zfs-discuss] Deduplication Memory Requirements

On Wed, May 04, 2011 at 03:49:12PM -0700, Erik Trimble wrote: > On 5/4/2011 2:54 PM, Ray Van Dolson wrote: > > On Wed, May 04, 2011 at 12:29:06PM -0700, Erik Trimble wrote: > >> (2) Block size: a 4k block size will yield better dedup than a 128k > >> block size, presuming reasonable data turnover.

Re: [zfs-discuss] Deduplication Memory Requirements

On Wed, May 04, 2011 at 02:55:55PM -0700, Brandon High wrote: > On Wed, May 4, 2011 at 12:29 PM, Erik Trimble wrote: > >        I suspect that NetApp does the following to limit their resource > > usage:   they presume the presence of some sort of cache that can be > > dedicated to the DDT (and, s

Re: [zfs-discuss] Deduplication Memory Requirements

On 5/4/2011 2:54 PM, Ray Van Dolson wrote: On Wed, May 04, 2011 at 12:29:06PM -0700, Erik Trimble wrote: (2) Block size: a 4k block size will yield better dedup than a 128k block size, presuming reasonable data turnover. This is inherent, as any single bit change in a block will make it non-du

Re: [zfs-discuss] Deduplication Memory Requirements

On Wed, May 4, 2011 at 12:29 PM, Erik Trimble wrote: >        I suspect that NetApp does the following to limit their resource > usage:   they presume the presence of some sort of cache that can be > dedicated to the DDT (and, since they also control the hardware, they can > make sure there is alw

Re: [zfs-discuss] Deduplication Memory Requirements

On Wed, May 04, 2011 at 12:29:06PM -0700, Erik Trimble wrote: > On 5/4/2011 9:57 AM, Ray Van Dolson wrote: > > There are a number of threads (this one[1] for example) that describe > > memory requirements for deduplication. They're pretty high. > > > > I'm trying to get a better understanding... o

Re: [zfs-discuss] Deduplication Memory Requirements

On 5/4/2011 9:57 AM, Ray Van Dolson wrote: There are a number of threads (this one[1] for example) that describe memory requirements for deduplication. They're pretty high. I'm trying to get a better understanding... on our NetApps we use 4K block sizes with their post-process deduplication and

[zfs-discuss] Deduplication Memory Requirements

There are a number of threads (this one[1] for example) that describe memory requirements for deduplication. They're pretty high. I'm trying to get a better understanding... on our NetApps we use 4K block sizes with their post-process deduplication and get pretty good dedupe ratios for VM content