master - RAID: Make "raid1" the default mirror segment type

master - RAID: Make "raid1" the default mirror segment type

[Jonathan Brassow]

Gitweb:        http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=7e1083c985fd130b240c2471643350cc5c0f05cf
Commit:        7e1083c985fd130b240c2471643350cc5c0f05cf
Parent:        f74e8fe04471a44fe1ab0645e48c9cb06ef6fb4f
Author:        Jonathan Brassow <jbrassow@redhat.com>
AuthorDate:    Tue Aug 6 14:13:55 2013 -0500
Committer:     Jonathan Brassow <jbrassow@redhat.com>
CommitterDate: Tue Aug 6 14:13:55 2013 -0500

RAID: Make "raid1" the default mirror segment type

---
 WHATS_NEW             |    1 +
 conf/example.conf.in  |    2 +-
 lib/config/defaults.h |    2 +-
 man/lvconvert.8.in    |    7 ++++++-
 man/lvcreate.8.in     |   17 ++++++++++++-----
 5 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/WHATS_NEW b/WHATS_NEW
index fd7e39f..3590e64 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.02.100 -
 ================================
+  Make "raid1" the default mirror segment type.
   Fix clogd descriptor leak when daemonizing.
   Fix clvmd descriptor leak on restart.
   Add pipe_open/close() to replace less secure popen() glibc call.
diff --git a/conf/example.conf.in b/conf/example.conf.in
index 0e313c8..c3ba2b9 100644
--- a/conf/example.conf.in
+++ b/conf/example.conf.in
@@ -512,7 +512,7 @@ global {
     #
     # Specify the '--type <mirror|raid1>' option to override this default
     # setting.
-    mirror_segtype_default = "mirror"
+    mirror_segtype_default = "raid1"
 
     # 'raid10_segtype_default' determines the segment types used by default
     # when the '--stripes/-i' and '--mirrors/-m' arguments are both specified
diff --git a/lib/config/defaults.h b/lib/config/defaults.h
index 5af0f00..59282c5 100644
--- a/lib/config/defaults.h
+++ b/lib/config/defaults.h
@@ -51,7 +51,7 @@
 #define DEFAULT_METADATA_READ_ONLY 0
 #define DEFAULT_LVDISPLAY_SHOWS_FULL_DEVICE_PATH 0
 
-#define DEFAULT_MIRROR_SEGTYPE "mirror"
+#define DEFAULT_MIRROR_SEGTYPE "raid1"
 #define DEFAULT_MIRRORLOG "disk"
 #define DEFAULT_MIRROR_LOG_FAULT_POLICY "allocate"
 #define DEFAULT_MIRROR_IMAGE_FAULT_POLICY "remove"
diff --git a/man/lvconvert.8.in b/man/lvconvert.8.in
index d4faf27..0fe5ab3 100644
--- a/man/lvconvert.8.in
+++ b/man/lvconvert.8.in
@@ -141,7 +141,12 @@ Run the daemon in the background.
 Specifies the degree of the mirror you wish to create.
 For example, "\fB-m 1\fP" would convert the original logical
 volume to a mirror volume with 2-sides; that is, a
-linear volume plus one copy.
+linear volume plus one copy.  There are two implementations of mirroring
+which correspond to the "raid1" and "mirror" segment types.  The default
+mirroring segment type is "raid1".  If the legacy "mirror" segment type
+is desired, the \fB\-\-type\fP argument must be used to explicitly
+select the desired type.  The \fB\-\-mirrorlog\fP and \fB\-\-corelog\fP
+options below are only relevant to the legacy "mirror" segment type.
 .TP
 .IR \fB\-\-mirrorlog " {" disk | core | mirrored }
 Specifies the type of log to use.
diff --git a/man/lvcreate.8.in b/man/lvcreate.8.in
index 681ff68..4a29720 100644
--- a/man/lvcreate.8.in
+++ b/man/lvcreate.8.in
@@ -232,16 +232,23 @@ afterwards will be mirrored, but the original contents will not be
 copied.  This is useful for skipping a potentially long and resource
 intensive initial sync of an empty device.
 
-The optional argument \fB\-\-mirrorlog\fP specifies the type of log to be used.
+There are two implementations of mirroring which can be used and correspond
+to the "raid1" and "mirror" segment types.  The default is "raid1".  See the
+\fB\-\-type\fP option for more information if you would like to use the
+legacy "mirror" segment type.  The \fB\-\-mirrorlog\fP and \fB\-\-corelog\fP
+options apply to the "mirror" segment type only.
+
+The optional argument \fB\-\-mirrorlog\fP specifies the type of log to be
+used for logical volumes utilizing the legacy "mirror" segment type.
 The default is \fIdisk\fP, which is persistent and requires
 a small amount of storage space, usually on a separate device from the
 data being mirrored.  Using \fIcore\fP means the mirror is regenerated
-by copying the data from the first device again each time the
-device is activated, for example, after every reboot.  Using \fImirrored\fP
+by copying the data from the first device each time the logical
+volume is activated, like after every reboot.  Using \fImirrored\fP
 will create a persistent log that is itself mirrored.
 
-The optional argument \fB\-\-corelog\fP is equivalent
-to \fB\-\-mirrorlog\fP \fIcore\fP.
+When the legacy "mirror" segment type is used, the optional argument
+\fB\-\-corelog\fP is equivalent to \fB\-\-mirrorlog\fP \fIcore\fP.
 .TP
 .IR \fB\-M ", " \fB\-\-persistent " {" y | n }
 Set to \fIy\fP to make the minor number specified persistent.

master - RAID: Make "raid1" the default mirror segment type

[Zdenek Kabelac]

Dne 6.8.2013 21:14, Jonathan Brassow napsal(a):
> Gitweb:        http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=7e1083c985fd130b240c2471643350cc5c0f05cf
> Commit:        7e1083c985fd130b240c2471643350cc5c0f05cf
> Parent:        f74e8fe04471a44fe1ab0645e48c9cb06ef6fb4f
> Author:        Jonathan Brassow <jbrassow@redhat.com>
> AuthorDate:    Tue Aug 6 14:13:55 2013 -0500
> Committer:     Jonathan Brassow <jbrassow@redhat.com>
> CommitterDate: Tue Aug 6 14:13:55 2013 -0500
>
> RAID: Make "raid1" the default mirror segment type
>
> ---
>   WHATS_NEW             |    1 +
>   conf/example.conf.in  |    2 +-
>   lib/config/defaults.h |    2 +-
>   man/lvconvert.8.in    |    7 ++++++-
>   man/lvcreate.8.in     |   17 ++++++++++++-----
>   5 files changed, 21 insertions(+), 8 deletions(-)
>
> diff --git a/WHATS_NEW b/WHATS_NEW
> index fd7e39f..3590e64 100644
> --- a/WHATS_NEW
> +++ b/WHATS_NEW
> @@ -1,5 +1,6 @@
>   Version 2.02.100 -
>   ================================
> +  Make "raid1" the default mirror segment type.
>     Fix clogd descriptor leak when daemonizing.
>     Fix clvmd descriptor leak on restart.
>     Add pipe_open/close() to replace less secure popen() glibc call.
> diff --git a/conf/example.conf.in b/conf/example.conf.in
> index 0e313c8..c3ba2b9 100644
> --- a/conf/example.conf.in
> +++ b/conf/example.conf.in
> @@ -512,7 +512,7 @@ global {
>       #
>       # Specify the '--type <mirror|raid1>' option to override this default
>       # setting.
> -    mirror_segtype_default = "mirror"
> +    mirror_segtype_default = "raid1"
>


We need fallback here - since if the user doesn't have dm-raid -  then he 
needs to manually configure defaults.

As a result automated tests on systems without dm raid fails.

Also we need to update all tests which were supposed to test mirrors,
to really test mirrors - otherwise we are checking raid code twice
(and even without checking  dm-raid version presence)

Zdenek

master - RAID: Make "raid1" the default mirror segment type

[Brassow Jonathan]

On Aug 7, 2013, at 4:21 AM, Zdenek Kabelac wrote:

> 
> We need fallback here - since if the user doesn't have dm-raid -  then he needs to manually configure defaults.
> 
> As a result automated tests on systems without dm raid fails.
> 
> Also we need to update all tests which were supposed to test mirrors,
> to really test mirrors - otherwise we are checking raid code twice
> (and even without checking  dm-raid version presence)

I'll fix-up all the mirror tests today.

Not sure about what to do regarding a user on an old system with fresh LVM.  The commands should complain about not having RAID kernel support.  Do we overwrite their current lvm.conf when installing?  I don't think so...

 brassow

master - RAID: Make "raid1" the default mirror segment type

[Peter Rajnoha]

On 08/07/2013 04:03 PM, Brassow Jonathan wrote:
> 
> On Aug 7, 2013, at 4:21 AM, Zdenek Kabelac wrote:
> 
>>
>> We need fallback here - since if the user doesn't have dm-raid -  then he needs to manually configure defaults.
>>
>> As a result automated tests on systems without dm raid fails.
>>
>> Also we need to update all tests which were supposed to test mirrors,
>> to really test mirrors - otherwise we are checking raid code twice
>> (and even without checking  dm-raid version presence)
> 
> I'll fix-up all the mirror tests today.
> 
> Not sure about what to do regarding a user on an old system with fresh LVM.  The commands should complain about not having RAID kernel support.  Do we overwrite their current lvm.conf when installing?  I don't think so...
> 

We do have a patch attached to RHEL5 already that removes some RAID stuff from lvm.conf
(the mirror_segtype_default setting):

  http://pkgs.devel.redhat.com/cgit/rpms/lvm2/tree/lvm2-rhel5.patch?h=rhel-5.9

We can change that if needed...

Peter

master - RAID: Make "raid1" the default mirror segment type

[Brassow Jonathan]

On Aug 7, 2013, at 9:35 AM, Peter Rajnoha wrote:

> On 08/07/2013 04:03 PM, Brassow Jonathan wrote:
>> 
>> On Aug 7, 2013, at 4:21 AM, Zdenek Kabelac wrote:
>> 
>>> 
>>> We need fallback here - since if the user doesn't have dm-raid -  then he needs to manually configure defaults.
>>> 
>>> As a result automated tests on systems without dm raid fails.
>>> 
>>> Also we need to update all tests which were supposed to test mirrors,
>>> to really test mirrors - otherwise we are checking raid code twice
>>> (and even without checking  dm-raid version presence)
>> 
>> I'll fix-up all the mirror tests today.
>> 
>> Not sure about what to do regarding a user on an old system with fresh LVM.  The commands should complain about not having RAID kernel support.  Do we overwrite their current lvm.conf when installing?  I don't think so...
>> 
> 
> We do have a patch attached to RHEL5 already that removes some RAID stuff from lvm.conf
> (the mirror_segtype_default setting):
> 
>  http://pkgs.devel.redhat.com/cgit/rpms/lvm2/tree/lvm2-rhel5.patch?h=rhel-5.9
> 
> We can change that if needed...

We will definitely need to do that - and for RHEL6 now too.  RAID1/10 should only become the default upstream and in RHEL7.

I think Zdenek was talking mostly about users who compile their own LVM on machines with older kernels though.

 brassow