Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-17 Thread Imran Geriskovan
On 12/12/13, Chris Mason wrote: > For me anyway, data=dup in mixed mode is definitely an accident ;) > I personally think data dup is a false sense of security, but drives > have gotten so huge that it may actually make sense in a few > configurations. Sure, it's not about any security regarding

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-13 Thread Duncan
David Sterba posted on Thu, 12 Dec 2013 18:58:16 +0100 as excerpted: > I've been testing --mixed mode with various other raid profiles types as > far as I remember. Some bugs popped up, reported and Josef fixed them. FWIW, I'm running a mixed-mode btrfs-raid1 mode here on my log partition and ha

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-12 Thread David Sterba
On Thu, Dec 12, 2013 at 10:57:33AM -0500, Chris Mason wrote: > Quoting Duncan (2013-12-11 13:27:53) > > Imran Geriskovan posted on Wed, 11 Dec 2013 15:19:29 +0200 as excerpted: > > > > > Now, there is one open issue: > > > In its current form "-d dup" interferes with "-M". Is it constraint of > >

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-12 Thread Chris Mason
Quoting Duncan (2013-12-11 13:27:53) > Imran Geriskovan posted on Wed, 11 Dec 2013 15:19:29 +0200 as excerpted: > > > Now, there is one open issue: > > In its current form "-d dup" interferes with "-M". Is it constraint of > > design? > > Or an arbitrary/temporary constraint. What will be the situ

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-11 Thread Duncan
Imran Geriskovan posted on Wed, 11 Dec 2013 15:19:29 +0200 as excerpted: > Now, there is one open issue: > In its current form "-d dup" interferes with "-M". Is it constraint of > design? > Or an arbitrary/temporary constraint. What will be the situation if > there is tunable duplicates? I believ

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-11 Thread Duncan
Hugo Mills posted on Wed, 11 Dec 2013 08:09:02 + as excerpted: > On Tue, Dec 10, 2013 at 09:07:21PM -0700, Chris Murphy wrote: >> >> On Dec 10, 2013, at 8:19 PM, Imran Geriskovan >> wrote: >> > >> > Now the question is, is it a good practice to use "-M" for large >> > filesystems? >> >> Un

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-11 Thread Chris Murphy
On Dec 11, 2013, at 1:09 AM, Hugo Mills wrote: > That documentation needs tweaking. You need --mixed/-M for larger > filesystems than that. It's hard to say exactly where the optimal > boundary is, but somewhere around 16 GiB seems to be the dividing > point (8 GiB is in the "mostly going to c

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-11 Thread Imran Geriskovan
>> What's more (in relation to our long term data integrity aim) >> order of magnitude for their unpowered data retension period is >> 1 YEAR. (Read it as 6months to 2-3 years. > Does btrfs need to date-stamp each block/chunk to ensure that data is > rewritten before suffering flash memory bitrot?

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-11 Thread Martin
On 11/12/13 03:19, Imran Geriskovan wrote: SSDs: > What's more (in relation to our long term data integrity aim) > order of magnitude for their unpowered data retension period is > 1 YEAR. (Read it as 6months to 2-3 years. While powered they > refresh/shuffle the blocks) This makes SSDs > unsuita

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-11 Thread Imran Geriskovan
> That's actually the reason btrfs defaults to SINGLE metadata mode on > single-device SSD-backed filesystems, as well. > > But as Imran points out, SSDs aren't all there is. There's still > spinning rust around. > > And defaults aside, even on SSDs it should be /possible/ to specify data- > dup m

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-11 Thread Duncan
Chris Murphy posted on Tue, 10 Dec 2013 17:33:59 -0700 as excerpted: > On Dec 10, 2013, at 5:14 PM, Imran Geriskovan > wrote: > >>> Current btrfs-progs is v3.12. 0.19 is a bit old. But yes, looks like >>> the wiki also needs updating. >> >>> Anyway I just tried it on an 8GB stick and it works,

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-11 Thread Hugo Mills
On Tue, Dec 10, 2013 at 09:07:21PM -0700, Chris Murphy wrote: > > On Dec 10, 2013, at 8:19 PM, Imran Geriskovan > wrote: > > > > Now the question is, is it a good practice to use "-M" for large > > filesystems? > > Pros, Cons? What is the performance impact? Or any other possible impact? > >

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-10 Thread Duncan
Chris Murphy posted on Tue, 10 Dec 2013 17:33:59 -0700 as excerpted: > On Dec 10, 2013, at 5:14 PM, Imran Geriskovan > wrote: > >> As being the lead developer, is it possible for you to >> provide some insights for the reliability of this option? > > I'm not a developer, I'm just an ape who wea

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-10 Thread Chris Murphy
On Dec 10, 2013, at 8:19 PM, Imran Geriskovan wrote: > > Now the question is, is it a good practice to use "-M" for large filesystems? > Pros, Cons? What is the performance impact? Or any other possible impact? Uncertain. man mkfs.btrfs says "Mix data and metadata chunks together for more eff

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-10 Thread Imran Geriskovan
> I'm not a developer, I'm just an ape who wears pants. Chris Mason is the > lead developer. All I can say about it is that it's been working for me OK > so far. Great:) Now, I understand that you were using "-d dup", which is quite valuable for me. And since GMail only show first names in Inbox l

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-10 Thread Chris Murphy
On Dec 10, 2013, at 5:14 PM, Imran Geriskovan wrote: >> Current btrfs-progs is v3.12. 0.19 is a bit old. But yes, looks like the >> wiki also needs updating. > >> Anyway I just tried it on an 8GB stick and it works, but -M (mixed >> data+metadata) is required, which documentation also says inc

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-10 Thread Chris Murphy
On Dec 10, 2013, at 4:33 PM, Imran Geriskovan wrote: >>> Currently, if you want to protect your data against bit-rot on >>> a single device you must have 2 btrfs partitions and mount >>> them as Raid1. > >> No this also works: >> mkfs.btrfs -d dup -m dup -M > > Thanks a lot. > > I guess doc

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-10 Thread Imran Geriskovan
>> Currently, if you want to protect your data against bit-rot on >> a single device you must have 2 btrfs partitions and mount >> them as Raid1. > No this also works: > mkfs.btrfs -d dup -m dup -M Thanks a lot. I guess docs need an update: https://btrfs.wiki.kernel.org/index.php/Mkfs.btrfs: "

Re: Feature Req: "mkfs.btrfs -d dup" option on single device

2013-12-10 Thread Chris Murphy
On Dec 10, 2013, at 1:31 PM, Imran Geriskovan wrote: > Currently, if you want to protect your data against bit-rot on > a single device you must have 2 btrfs partitions and mount > them as Raid1. No this also works: mkfs.btrfs -d dup -m dup -M Chris Murphy -- To unsubscribe from this list