Windows 7 Disk Management: spanned volume won't re-integrate missingdisk

On 09/01/13 01:10, Yousuf Khan wrote:
On 08/01/2013 5:30 PM, Paul wrote:
Franc Zabkar wrote:
On Tue, 08 Jan 2013 08:27:31 -0500, Yousuf Khan
put finger to keyboard and composed:

He did mention trying the "Reactivate" command in Disk Management,
which of course didn't work. Could Reactivate call an Initialize?

I don't know, but I would think not. Microsoft's technical articles
aren't really helpful in this regard, though. I like to see what
happens at the bits-and-bytes level, but Microsoft rarely goes that
deep.

- Franc Zabkar

Reactivate might exist for the purpose of handling a "hot inserted"
span or RAID member. Like plugging a SATA drive into a SATA backplane
with the power on.

The Windows 7 version (even for Ultimate) of Disk Management doesn't
include any RAID beyond spanning, striping, or mirroring. I found that
out the hard way, when I tried to create some RAID5 partitions, and
found it all greyed out. Looked it up and saw it was only for Windows
Server. I'm not sure I'd trust the Disk Management on Server editions
either, considering the stuff we went through here.


I know that XP Pro only supports RAID0 and RAID1 out of the box, and you
need a server version to support RAID5. But support for RAID5 can be
"added" to XP by a few registry tweaks. Maybe the same applies with
Win7? Of course, such tweaks are unlikely to be supported by MS...

On Mon, 07 Jan 2013 13:20:49 -0500, Yousuf Khan
put finger to keyboard and composed:

Okay, PTEdit worked!!! The partition table on this disk was showing Type
0 "empty", so I used Ptedit to turn them into Type 42 (Dynamic Disk). I
also had to fill in the remaining fields in that partition table by
hand: Starting Cylinder/Head/Sector = all zeros; Ending Cyl/Head/Sector
= 1023/254/63; Sectors Before = zero; Sectors End = Total Sectors -
2111. I found these other parameters out by comparing them to the other
disks in the dynamic volume.

I confess that I know nothing about dynamic disks but ISTM that the
CHS numbers don't make sense.

Firstly, sector numbers begin counting from 1, not 0.

C/H/S values of 1023/254/63 would suggest that the partition size is
about 16 million sectors, not 2111. I realise that these values are
used when the partition size is greater than 8GB, but that doesn't
seem to fit with the rest of the partition table data.

Furthermore, 2111 = 63 + 2048, so I'm wondering whether there is a
1MiB partition beginning at sector 63. Sector 63 is where the first
traditional MBR partition begins, not LBA 0.

In fact the following URL has this to say:

"If a partition table entry of type 0x42 is present in the legacy
partition table, then W2K ignores the legacy partition table and uses
a proprietary partition table and a proprietary partitioning scheme
(LDM or DDM). As the Microsoft KnowledgeBase writes: Pure dynamic
disks (those not containing any hard-linked partitions) have only a
single partition table entry (type 42) to define the entire disk.
Dynamic disks store their volume configuration in a database located
in a 1-MB private region at the end of each dynamic disk."

http://www.win.tue.nl/~aeb/partition...n_types-1.html

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

On 12/01/2013 10:30 AM, David Brown wrote:
On 09/01/13 01:10, Yousuf Khan wrote:
The Windows 7 version (even for Ultimate) of Disk Management doesn't
include any RAID beyond spanning, striping, or mirroring. I found that
out the hard way, when I tried to create some RAID5 partitions, and
found it all greyed out. Looked it up and saw it was only for Windows
Server. I'm not sure I'd trust the Disk Management on Server editions
either, considering the stuff we went through here.


I know that XP Pro only supports RAID0 and RAID1 out of the box, and you
need a server version to support RAID5. But support for RAID5 can be
"added" to XP by a few registry tweaks. Maybe the same applies with
Win7? Of course, such tweaks are unlikely to be supported by MS...

Possibly, however this is Microsoft's official response to why RAID-5 is
greyed out in Disk Management:

"New RAID-5 Volume..." greyed out in Disk Management
http://social.technet.microsoft.com/...c-30ba7c6cf080

So I guess RAID-5 requires even more expenditure to get enabled, beyond
Windows 7 Ultimate. You need to go straight to Windows Server.

But the following thread even mentions that even if I had Windows
Server, I probably wouldn't really want to use the software RAID-5 on
it, because it's so slow:

Establishing a software RAID5 with Diskpart seems to take DAYS with no
end in sight - what gives?
http://social.technet.microsoft.com/...0-f513b6141608

Yousuf Khan

On 12/01/2013 3:49 PM, Franc Zabkar wrote:
On Mon, 07 Jan 2013 13:20:49 -0500, Yousuf Khan
put finger to keyboard and composed:

Okay, PTEdit worked!!! The partition table on this disk was showing Type
0 "empty", so I used Ptedit to turn them into Type 42 (Dynamic Disk). I
also had to fill in the remaining fields in that partition table by
hand: Starting Cylinder/Head/Sector = all zeros; Ending Cyl/Head/Sector
= 1023/254/63; Sectors Before = zero; Sectors End = Total Sectors -
2111. I found these other parameters out by comparing them to the other
disks in the dynamic volume.

I confess that I know nothing about dynamic disks but ISTM that the
CHS numbers don't make sense.

Firstly, sector numbers begin counting from 1, not 0.

Yup, sorry, I made a mistake when writing that one, I was operating from
memory since I wasn't near the original system. The actual values for
that should be:

Starting Cylinder/Head/Sector = 0/1/1

The Ending CHS values are right though.

C/H/S values of 1023/254/63 would suggest that the partition size is
about 16 million sectors, not 2111. I realise that these values are
used when the partition size is greater than 8GB, but that doesn't
seem to fit with the rest of the partition table data.

No, I'm not saying that the partition size is only 2111 sectors, I'm
saying that you need to _subtract_ 2111 sectors from the total number of
sectors and put that value in here, let me rewrite it on its own line, thus:

Sectors End = Total Sectors - 2111

So if you have 1,000,000 sectors total in your disk, then you would put
997,889 sectors in this field, i.e. 1000000 - 2111 = 997889.

2111 sectors is about equal to 1 MB, which would be just about the right
size for the metadata database for the dynamic disks.

Furthermore, 2111 = 63 + 2048, so I'm wondering whether there is a
1MiB partition beginning at sector 63. Sector 63 is where the first
traditional MBR partition begins, not LBA 0.

Probably nearly right, except I'm thinking that the 63 + 2048 is around
the end of the disk, rather than around the beginning.

Yousuf Khan

Yousuf Khan wrote:
On 12/01/2013 10:30 AM, David Brown wrote:
On 09/01/13 01:10, Yousuf Khan wrote:
The Windows 7 version (even for Ultimate) of Disk Management doesn't
include any RAID beyond spanning, striping, or mirroring. I found that
out the hard way, when I tried to create some RAID5 partitions, and
found it all greyed out. Looked it up and saw it was only for Windows
Server. I'm not sure I'd trust the Disk Management on Server editions
either, considering the stuff we went through here.


I know that XP Pro only supports RAID0 and RAID1 out of the box, and you
need a server version to support RAID5. But support for RAID5 can be
"added" to XP by a few registry tweaks. Maybe the same applies with
Win7? Of course, such tweaks are unlikely to be supported by MS...

Possibly, however this is Microsoft's official response to why RAID-5 is
greyed out in Disk Management:

"New RAID-5 Volume..." greyed out in Disk Management
http://social.technet.microsoft.com/...c-30ba7c6cf080


So I guess RAID-5 requires even more expenditure to get enabled, beyond
Windows 7 Ultimate. You need to go straight to Windows Server.

But the following thread even mentions that even if I had Windows
Server, I probably wouldn't really want to use the software RAID-5 on
it, because it's so slow:

Establishing a software RAID5 with Diskpart seems to take DAYS with no
end in sight - what gives?
http://social.technet.microsoft.com/...0-f513b6141608


Yousuf Khan

The recipe for that, was shown on Tomshardware many moons ago.
This is for WinXP. Editing executables might not pass OS
scrutiny (i.e. signing) on a newer OS.

http://www.tomshardware.com/reviews/...pen,925-2.html

Paul

On 13/01/13 07:14, Paul wrote:
Yousuf Khan wrote:
On 12/01/2013 10:30 AM, David Brown wrote:
On 09/01/13 01:10, Yousuf Khan wrote:
The Windows 7 version (even for Ultimate) of Disk Management doesn't
include any RAID beyond spanning, striping, or mirroring. I found that
out the hard way, when I tried to create some RAID5 partitions, and
found it all greyed out. Looked it up and saw it was only for Windows
Server. I'm not sure I'd trust the Disk Management on Server editions
either, considering the stuff we went through here.


I know that XP Pro only supports RAID0 and RAID1 out of the box, and you
need a server version to support RAID5. But support for RAID5 can be
"added" to XP by a few registry tweaks. Maybe the same applies with
Win7? Of course, such tweaks are unlikely to be supported by MS...

Possibly, however this is Microsoft's official response to why RAID-5
is greyed out in Disk Management:

"New RAID-5 Volume..." greyed out in Disk Management
http://social.technet.microsoft.com/...c-30ba7c6cf080


So I guess RAID-5 requires even more expenditure to get enabled,
beyond Windows 7 Ultimate. You need to go straight to Windows Server.

But the following thread even mentions that even if I had Windows
Server, I probably wouldn't really want to use the software RAID-5 on
it, because it's so slow:

Establishing a software RAID5 with Diskpart seems to take DAYS with no
end in sight - what gives?
http://social.technet.microsoft.com/...0-f513b6141608

Many people see the terms "Windows" and "reliable storage" as things
that don't belong together in the same sentence!

There are several reasons why someone would want to use raid. You might
want to combine smaller disks into a larger storage unit, or into a
faster storage unit. You might want it to keep your data safe in the
event of hardware failures occurring between backups (because raid is
/not/ a substitute for backups!). But the big reason in many cases is
to minimise down-time - you want to keep the system up and running even
if there is a failure, rather than having to rebuild things and restore
from backups.

Windows idea of software raid cannot give you this. In particular, you
can't use the software raid for the system disk. So if you are
interested in minimising down-time, Windows raid is useless.

And judging from people's experiences with Windows software raid (note -
there will be a bias here, because people post on the internet when they
have problems rather than when everything works fine), it is neither
particularly fast nor particularly reliable.

So the only reason to look at Windows software raid at all is for
putting together large storage areas where you are not concerned about
the data (or at least have good enough backups). And for that purpose
you might as well use RAID0 instead of RAID5.

Maybe MS has figured out that anyone looking for anything else with raid
on Windows will use either fake raid or hardware raid, so there is no
need to keep it in the system.




Yousuf Khan

The recipe for that, was shown on Tomshardware many moons ago.
This is for WinXP. Editing executables might not pass OS
scrutiny (i.e. signing) on a newer OS.

http://www.tomshardware.com/reviews/...pen,925-2.html

Paul

So it was a little more than just a few registry tweaks. The same
technique might be possible for Win7, if someone figures out the details
- but would anyone want to?

On 1/13/2013 4:56 AM, David Brown wrote:
There are several reasons why someone would want to use raid. You might
want to combine smaller disks into a larger storage unit, or into a
faster storage unit. You might want it to keep your data safe in the
event of hardware failures occurring between backups (because raid is
/not/ a substitute for backups!). But the big reason in many cases is to
minimise down-time - you want to keep the system up and running even if
there is a failure, rather than having to rebuild things and restore
from backups.

I don't find those solutions very satisfactory. So in the early 80's, I
came up with what I thought was a near perfect solution. While many talk
about and making a big deal about software backups, I think that isn't
good enough. Maybe because I am an electronic engineer, I see all kinds
of flaws here.

So while software backups are only partially helpful, I find hardware
and software cloning to be a far better solution. And no service plan on
Earth for any amount of money is better than what I have. And one of the
key factors that everybody seems to miss is to buy hardware in at least
in pairs.

Say for example, right now something happens with this computer I am
typing on. It could be anything you can think of. Power supply, fan,
CPU, RAM, hard drive, keyboard, monitor, motherboard, etc. failure. And
none of it matters because in 2 seconds I am back up and running again.

If the hard drive is at least ok, I just pop it out and slip it into
another M465 and I am up and going again. If the hard drive is partly or
the whole problem, I just grab the latest clone (I keep about 11 clones
for this machine alone) and I am off to the races in 4 seconds. And I
have it automatically synced with my latest data files.

Not only is this method more reliable than anything I have ever seen,
but it makes troubleshooting a real snap. As sometimes a problem pops up
and you generally have to jump through a number of hoops to see if a
problem is actually hardware or software. Not here, just pop the drive
in another machine and if the problem is still there, it will be
software. If gone, it's the hardware. This is a bit over simplified of
course, but it basically works this easy.

And no matter what the problem turns out to be, no big deal. As I have
spares of both software and hardware. And there is no real pending rush
to repair anything. Take your time if you like. As I have 7 more
functioning spares of this laptop alone and 11 hard drives that all have
to fail before I would be in a really big rush. And quite frankly, I
never see that day coming. ;-)

--
Bill
Gateway M465e ('06 era) - Thunderbird v12
Centrino Core2 Duo T7400 2.16 GHz - 4GB - Windows 8