MD RAID DEVICES INFO
MD has been unsupported since the 2.2 series of kernels (it wasn't marked as such because nobody realised this until the 2.2.13->2.2.14 patch.
Since everyone has been asking about it I figured I'd let everyone know.
If someone wants to pick it up drop by l-k and check and see if anyone ahs yet.
--
Michael Loftis
[email protected] ICQ: 15648280 AIM: DyJailBait
Funny quip of the moment just happens to be....
Linux is like a tent:
no gates, no windows, and an Apache inside!
The MD functionality has only just matured, how is this to be moved forward into 2.4? Is the MD functionality being rolled into LVM? What about duplication of effort.... I take it that large portions of code can be shared?
I am told that LVM supports only linear and RAID0 which is hardly useful... I appreciate that this is a work in progress but with 2.4 on the horizon can we really justify dropping a well tested and functional system for somthing without the major functionality of MD?
Perhaps somone can let me know how they see this moving forward?
Quoted 17 lines · Michael Loftis
MD has been unsupported since the 2.2 series of kernels (it wasn't marked as such because nobody realised this until the 2.2.13->2.2.14 patch.
Since everyone has been asking about it I figured I'd let everyone know.
If someone wants to pick it up drop by l-k and check and see if anyone ahs yet.
--
Michael Loftis
[email protected] ICQ: 15648280 AIM: DyJailBait
Funny quip of the moment just happens to be....
Linux is like a tent:
no gates, no windows, and an Apache inside!
Quoted 3 lines
The MD functionality has only just matured, how is this to be moved forward into 2.4?
Today there's MD concat and RAID0 only in 2.3.x.
Quoted 1 line
Is the MD functionality being rolled into LVM?
No.
I don't like to create moster ;-{)
A modular approach is better by far (see below).
Quoted 3 lines
What
about duplication of effort.... I take it that large portions of code can be shared?
No. It's not a question of large portions of code. Basically supporting RAID0 in LVM is fairly simple and gives you the choice for performance on which lower layer software or hardware solution..
Quoted 3 lines
I am told that LVM supports only linear and RAID0 which is hardly useful...
This is a misleading statement.
Actually it's a question of how to layer several functional parts on each other.
LVM basically gives you the flexibility of online resizing everything.
MD is the software solution which can be stacked below LVM to enable software RAID1/4/5.
OTOH you are able to use dedicated hardware RAID subsystems instead which are easier to administer and LVM on top of them to get the flexibility to resize.
IOW: MD is one solution to address disk subsystem redundancy,
hardware RAID subsystems is another.
Volume Management sits on top of one of these (or even on mixed configurations).
It can sit on top of multiple non redundant disks as well.
Quoted 3 lines
I appreciate that this is a work in progress but with 2.4 on the horizon can we really justify dropping a well tested and functional system for somthing without the major functionality of MD?
Nobody wants to drop MD AFAIK!
Heinz
Quoted 23 lines
Perhaps somone can let me know how they see this moving forward?
Quoted 17 lines · Michael Loftis
MD has been unsupported since the 2.2 series of kernels (it wasn't marked as such because nobody realised this until the 2.2.13->2.2.14 patch.
Since everyone has been asking about it I figured I'd let everyone know.
If someone wants to pick it up drop by l-k and check and see if anyone ahs yet.
--
Michael Loftis
[email protected] ICQ: 15648280 AIM: DyJailBait
Funny quip of the moment just happens to be....
Linux is like a tent:
no gates, no windows, and an Apache inside!
Signature · 11 lines
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Systemmanagement CS-TS T-Nova
Entwicklungszentrum Darmstadt
Heinz Mauelshagen Otto-Roehm-Strasse 71c
Senior Systems Engineer Postfach 10 05 41
64205 Darmstadt
[email protected] Germany
+49 6151 886-425
FAX-386
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-Ah,
It becomes clear, I was worried that there was major duplication of effort going on and that LVM was implimenting the MD functionality....
It seems logical that MD provide the underlying redundnancya nd LVM provide volume management...
Do I assume that MD will be available in 2.3/2.4 eventually..... it sounded from the original post that it was going to die....
Quoted 92 lines · Heinz Mauelshagen
Quoted 3 lines
The MD functionality has only just matured, how is this to be moved forward into 2.4?
Today there's MD concat and RAID0 only in 2.3.x.
Quoted 1 line
Is the MD functionality being rolled into LVM?
No.
I don't like to create moster ;-{)
A modular approach is better by far (see below).Quoted 3 lines
What
about duplication of effort.... I take it that large portions of code can be shared?No. It's not a question of large portions of code. Basically supporting RAID0 in LVM is fairly simple and gives you the choice for performance on which lower layer software or hardware solution..
Quoted 3 lines
I am told that LVM supports only linear and RAID0 which is hardly useful...
This is a misleading statement.
Actually it's a question of how to layer several functional parts on each other.
LVM basically gives you the flexibility of online resizing everything.MD is the software solution which can be stacked below LVM to enable software RAID1/4/5.
OTOH you are able to use dedicated hardware RAID subsystems instead which are easier to administer and LVM on top of them to get the flexibility to resize.
IOW: MD is one solution to address disk subsystem redundancy,
hardware RAID subsystems is another.
Volume Management sits on top of one of these (or even on mixed configurations).
It can sit on top of multiple non redundant disks as well.Quoted 3 lines
I appreciate that this is a work in progress but with 2.4 on the horizon can we really justify dropping a well tested and functional system for somthing without the major functionality of MD?
Nobody wants to drop MD AFAIK!
Heinz
Quoted 23 lines
Perhaps somone can let me know how they see this moving forward?
Quoted 17 lines · Michael Loftis
MD has been unsupported since the 2.2 series of kernels (it wasn't marked as such because nobody realised this until the 2.2.13->2.2.14 patch.
Since everyone has been asking about it I figured I'd let everyone know.
If someone wants to pick it up drop by l-k and check and see if anyone ahs yet.
--
Michael Loftis
[email protected] ICQ: 15648280 AIM: DyJailBait
Funny quip of the moment just happens to be....
Linux is like a tent:
no gates, no windows, and an Apache inside!Signature · 11 lines
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Systemmanagement CS-TS T-Nova Entwicklungszentrum Darmstadt Heinz Mauelshagen Otto-Roehm-Strasse 71c Senior Systems Engineer Postfach 10 05 41 64205 Darmstadt [email protected] Germany +49 6151 886-425 FAX-386 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Quoted 11 lines · A James Lewis
Ah,
It becomes clear, I was worried that there was major duplication of effort going on and that LVM was implimenting the MD functionality....
It seems logical that MD provide the underlying redundnancya nd LVM provide volume management...
Do I assume that MD will be available in 2.3/2.4 eventually..... it sounded from the original post that it was going to die....
The original poster was clearly misguided, there are no signs of MD dying in 2.3/2.4. Some functionality from MD 0.90 has not been merged yet (RAID5), because it requires some more infrastructure changes in 2.3.x, but that will hopefully be solved before 2.4.
-Andi
Quoted 96 lines · Heinz Mauelshagen
Quoted 93 lines
Quoted 4 lines
The MD functionality has only just matured, how is this to be moved forward into 2.4?
Today there's MD concat and RAID0 only in 2.3.x.
Quoted 1 line
Is the MD functionality being rolled into LVM?
No.
I don't like to create moster ;-{)
A modular approach is better by far (see below).Quoted 3 lines
What
about duplication of effort.... I take it that large portions of code can be shared?No. It's not a question of large portions of code. Basically supporting RAID0 in LVM is fairly simple and gives you the choice for performance on which lower layer software or hardware solution..
Quoted 3 lines
I am told that LVM supports only linear and RAID0 which is hardly useful...
This is a misleading statement.
Actually it's a question of how to layer several functional parts on each other.
LVM basically gives you the flexibility of online resizing everything.MD is the software solution which can be stacked below LVM to enable software RAID1/4/5.
OTOH you are able to use dedicated hardware RAID subsystems instead which are easier to administer and LVM on top of them to get the flexibility to resize.
IOW: MD is one solution to address disk subsystem redundancy,
hardware RAID subsystems is another.
Volume Management sits on top of one of these (or even on mixed configurations).
It can sit on top of multiple non redundant disks as well.Quoted 3 lines
I appreciate that this is a work in progress but with 2.4 on the horizon can we really justify dropping a well tested and functional system for somthing without the major functionality of MD?
Nobody wants to drop MD AFAIK!
Heinz
Quoted 23 lines
Perhaps somone can let me know how they see this moving forward?
Quoted 17 lines · Michael Loftis
MD has been unsupported since the 2.2 series of kernels (it wasn't marked as such because nobody realised this until the 2.2.13->2.2.14 patch.
Since everyone has been asking about it I figured I'd let everyone know.
If someone wants to pick it up drop by l-k and check and see if anyone ahs yet.
--
Michael Loftis
[email protected] ICQ: 15648280 AIM: DyJailBait
Funny quip of the moment just happens to be....
Linux is like a tent:
no gates, no windows, and an Apache inside!Signature · 11 lines
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Systemmanagement CS-TS T-Nova Entwicklungszentrum Darmstadt Heinz Mauelshagen Otto-Roehm-Strasse 71c Senior Systems Engineer Postfach 10 05 41 64205 Darmstadt [email protected] Germany +49 6151 886-425 FAX-386 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-