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

[Paul]

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.

If you're cold-booting with all members restored
in a set, it likely puts the mess back online all by itself.

There's no reason for "Reactivate" to delete an MBR. The
only thing that would do that, might be "convert Dynamic to Basic",
complete with its own warning dialogs etc. As a Dynamic to Basic
conversion is going to remove the protective 0x42 value and
allow the MBR to hold regular partition type entries.

http://www.win.tue.nl/~aeb/partitions/partition_types-1.html

"42 Windows 2000 dynamic extended partition marker"

Paul

 

[Yousuf Khan]

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.

If you're cold-booting with all members restored
in a set, it likely puts the mess back online all by itself.

I think this might have contributed to the mess here. He knew enough to
reboot the machine, but he didn't consider doing a complete shutdown and
restart to re-initialize the peripherals and power supply too. He was
simply doing warm reboots, and it wasn't fixing anything. Then
eventually panic and desperation set in, and he may have done something
without completely realizing the implications.

However, I might be completely off-base in suspecting human error here,
I did ask him today if he used the "Initialize" command, and watched him
recreating his steps, he didn't even know where to find it, so it's not
likely he hit it by accident.

There's no reason for "Reactivate" to delete an MBR. The
only thing that would do that, might be "convert Dynamic to Basic",
complete with its own warning dialogs etc. As a Dynamic to Basic
conversion is going to remove the protective 0x42 value and
allow the MBR to hold regular partition type entries.

Now, let's take a hypothetical situation where the Windows 7 version of
Disk Management *does* support software RAID5, or maybe even just
mirroring. If a disk dies and you replace it with a new disk, would the
Reactivate be used to resync the new drive to the existing volume? If
that's the case, then maybe it would have to call "Init" to setup the
new drive as a dynamic drive?

Yousuf Khan

 

[DevilsPGD]

In the last episode of <[email protected]>,

Home systems.

Both systems are just about out of capacity so I'm watching HDD prices with
the idea that the 15-drive system (16 drives if you include the OS) can be
expanded to 24 drives and the 9-drive system (10 with the OS) can be
expanded to 13 drives. By then, both systems will be physically out of room
and it's either time for an additional server or piecemeal replacement of
2TB drives with bigger units.

What sort of cases/enclosures are you using? I've got a couple boxes
that are reaching their limits due to physical room in the case and I'm
eyeballing replacements but haven't found anything that isn't horribly
over-priced yet.

My goal is 12-16 SATA drives per case, although +2 would be ideal so
that I can have a couple drives for the OS and fully fill my 2x8 SATA
RAID cards to capacity.

I was looking at
http://www.newegg.ca/Product/Product.aspx?Item=N82E16811147165 and
actually had one on order, but I needed a pair and they got discontinued
after I ordered one, so I cancelled the order.

 

[Char Jackson]

In the last episode of <[email protected]>,


What sort of cases/enclosures are you using? I've got a couple boxes
that are reaching their limits due to physical room in the case and I'm
eyeballing replacements but haven't found anything that isn't horribly
over-priced yet.

One is a Norco RPC-450B, advertised as being able to hold just 10 drives,
but the standard trick is to remove the optical drive bay and install a
third HDD bay, increasing its internal capacity to 15 3.5" drives plus a
2.5" drive mounted in a card slot on the mobo.

<http://www.newegg.com/Product/Product.aspx?Item=N82E16811219030>

At some point, I intend to replace the 450B (or build another system
entirely) with a Norco 24-drive chassis such as the RPC-4220 or 4224.

<http://www.newegg.com/Norco-Technologies-Inc/BrandStore/ID-10473>

My other case is a Lian-Li tower case, not sure of the model, that natively
holds 8 3.5" drives, but with creative use of adapters I currently have 10
drives installed and see a viable way to get to at least 13 or 14.

My goal is 12-16 SATA drives per case, although +2 would be ideal so
that I can have a couple drives for the OS and fully fill my 2x8 SATA
RAID cards to capacity.

I was looking at
http://www.newegg.ca/Product/Product.aspx?Item=N82E16811147165 and
actually had one on order, but I needed a pair and they got discontinued
after I ordered one, so I cancelled the order.

From a distance, I could confuse that Rosewill with my Norco.

 

[DevilsPGD]

In the last episode of <[email protected]>,

My other case is a Lian-Li tower case, not sure of the model, that natively
holds 8 3.5" drives, but with creative use of adapters I currently have 10
drives installed and see a viable way to get to at least 13 or 14.

Cool, thanks. I don't mind using adapters to turn external bays into
3.5" bays, but I'd love to find something that doesn't need it.

From a distance, I could confuse that Rosewill with my Norco.

Yeah. They have a non-hotswappable one that is even closer, but I do
like the idea of hotswappable bays since my RAID cards are all hotswap
capable/ready at this point.

OTOH, I guess there's not really a lot of space for innovation when it
comes to packing a lot of drives in a case with a motherboard at the
rear.

 

[Char Jackson]

In the last episode of <[email protected]>,


Yeah. They have a non-hotswappable one that is even closer, but I do
like the idea of hotswappable bays since my RAID cards are all hotswap
capable/ready at this point.

Some of the Norco cases are hot swappable, but I use Drivebender as a
pooling service and it gets testy when a pooled volume disappears.

OTOH, I guess there's not really a lot of space for innovation when it
comes to packing a lot of drives in a case with a motherboard at the
rear.

IIRC, Google just says to heck with the case and the AC power supply,
letting the mobo, drives, and DC supply just lie there naked. I suppose that
could be an option, but I like the finished look of having that stuff in a
case.

 

[DevilsPGD]

In the last episode of <[email protected]>,

IIRC, Google just says to heck with the case and the AC power supply,
letting the mobo, drives, and DC supply just lie there naked. I suppose that
could be an option, but I like the finished look of having that stuff in a
case.

That's not an option where I live, at least for the most part. We have
one machine mounted in a cabinet behind the TV, but other than that,
it's not practical.

 

[David Brown]

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...

 

[Franc Zabkar]

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/partitions/partition_types-1.html

- Franc Zabkar

 

[Yousuf Khan]

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...l/thread/a1851e42-c705-4558-920c-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...s/thread/df7228a9-98d3-431a-b530-f513b6141608

Yousuf Khan

 

[Yousuf Khan]

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

 

[Paul]

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...l/thread/a1851e42-c705-4558-920c-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...s/thread/df7228a9-98d3-431a-b530-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/windowsxp-make-raid-5-happen,925-2.html

Paul

 

[David Brown]

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.

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/windowsxp-make-raid-5-happen,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?

 

[BillW50]

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. ;-)