Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread Andre' Breiler
Hi, On Fri, 20 Jan 2006, Reuben Farrelly wrote: On 20/01/2006 11:32 a.m., Neil Brown wrote: The in-kernel autodetection in md is purely legacy support as far as I am concerned. md does volume detection in user space via 'mdadm'. Hrm. puzzled look How would I then start my md0 raid-1

Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread Lars Marowsky-Bree
On 2006-01-19T21:17:12, Phillip Susi [EMAIL PROTECTED] wrote: I am under the impression that dm is simpler/cleaner than md. That impression very well may be wrong, but if it is simpler, then that's a good thing. That impression is wrong in that general form. Both have advantages and

Re: Two RAID6 questions

2006-01-20 Thread Brad Campbell
John Rowe wrote: First, can raidreconf grow a RAID6 device? The man page doesn't seem to mention RAID6 at all. No, raidreconf has no knowledge of raid-6 at all. Second, with RAID5 or RAID6 my biggest fear is a system crash whilst the RAID is writing resulting in dirty blocks. Does RAID6

Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread Ross Vandegrift
On Fri, Jan 20, 2006 at 10:43:13AM +1100, Neil Brown wrote: dm and md are just two different interface styles to various bits of this. Neither is clearly better than the other, partly because different people have different tastes. Here's why it's great to have both: they have different

Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread Heinz Mauelshagen
On Fri, Jan 20, 2006 at 11:53:06AM +0100, Lars Marowsky-Bree wrote: On 2006-01-19T21:17:12, Phillip Susi [EMAIL PROTECTED] wrote: I am under the impression that dm is simpler/cleaner than md. That impression very well may be wrong, but if it is simpler, then that's a good thing.

Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread Heinz Mauelshagen
On Thu, Jan 19, 2006 at 09:17:12PM -0500, Phillip Susi wrote: Neil Brown wrote: Maybe the problem here is thinking of md and dm as different things. Try just not thinking of them at all. Think about it like this: The linux kernel support lvm The linux kernel support multipath The

Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread Heinz Mauelshagen
On Fri, Jan 20, 2006 at 10:43:13AM +1100, Neil Brown wrote: On Thursday January 19, [EMAIL PROTECTED] wrote: Neil Brown wrote: The in-kernel autodetection in md is purely legacy support as far as I am concerned. md does volume detection in user space via 'mdadm'. What other

Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread Lars Marowsky-Bree
On 2006-01-20T19:38:40, Heinz Mauelshagen [EMAIL PROTECTED] wrote: However, rewriting the RAID personalities for DM is a thing only a fool would do without really good cause. Thanks Lars ;) Well, I assume you have a really good cause then, don't you? ;-) Sincerely, Lars

Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread Lars Marowsky-Bree
On 2006-01-20T19:36:21, Heinz Mauelshagen [EMAIL PROTECTED] wrote: Then 'dmraid' (or a similar tool) can use 'dm' interfaces for some raid levels and 'md' interfaces for others. Yes, that's possible but there's recommendations to have a native target for dm to do RAID5, so I started to

Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread Heinz Mauelshagen
On Fri, Jan 20, 2006 at 11:57:24PM +0100, Lars Marowsky-Bree wrote: On 2006-01-20T19:36:21, Heinz Mauelshagen [EMAIL PROTECTED] wrote: Then 'dmraid' (or a similar tool) can use 'dm' interfaces for some raid levels and 'md' interfaces for others. Yes, that's possible but there's

Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread Heinz Mauelshagen
On Fri, Jan 20, 2006 at 11:09:51PM +0100, Lars Marowsky-Bree wrote: On 2006-01-20T19:38:40, Heinz Mauelshagen [EMAIL PROTECTED] wrote: However, rewriting the RAID personalities for DM is a thing only a fool would do without really good cause. Thanks Lars ;) Well, I assume you have

Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread Lars Marowsky-Bree
On 2006-01-21T01:01:42, Heinz Mauelshagen [EMAIL PROTECTED] wrote: Why not provide a dm-md wrapper which could then load/interface to all md personalities? As we want to enrich the mapping flexibility (ie, multi-segment fine grained mappings) of dm by adding targets as we go, a certain

Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread Heinz Mauelshagen
On Sat, Jan 21, 2006 at 01:03:44AM +0100, Lars Marowsky-Bree wrote: On 2006-01-21T01:01:42, Heinz Mauelshagen [EMAIL PROTECTED] wrote: Why not provide a dm-md wrapper which could then load/interface to all md personalities? As we want to enrich the mapping flexibility (ie, multi-segment

Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread Lars Marowsky-Bree
On 2006-01-21T01:08:06, Heinz Mauelshagen [EMAIL PROTECTED] wrote: A dm-md wrapper would give you the same? No, we'ld need to stack more complex to achieve mappings. Think lvm2 and logical volume level raid5. How would you not get that if you had a wrapper around md which made it into an dm

Re: [PATCH 000 of 5] md: Introduction

2006-01-20 Thread David Greaves
Andre' Breiler wrote: Hi, On Fri, 20 Jan 2006, Reuben Farrelly wrote: On 20/01/2006 11:32 a.m., Neil Brown wrote: The in-kernel autodetection in md is purely legacy support as far as I am concerned. md does volume detection in user space via 'mdadm'. Hrm. puzzled look How

Re: [PATCH 001 of 5] md: Split disks array out of raid5 conf structure so it is easier to grow.

2006-01-20 Thread John Stoffel
Neil == Neil Brown [EMAIL PROTECTED] writes: Neil On Tuesday January 17, [EMAIL PROTECTED] wrote: NeilBrown == NeilBrown [EMAIL PROTECTED] writes: NeilBrown Previously the array of disk information was included in NeilBrown the raid5 'conf' structure which was allocated to an NeilBrown