Questions about RAID setup

[ScottHW]

I am not new to RAID in the IT world, but never set it up at home. In
the next month or two I will be building a new AMD X2 PC using either
an Abit or ASUS mobo, one the latest SLI boards which include RAID. I
am targeting RAID 1, as I am not that concerned about performance, but
very concerned about redundancy. Here are my questions:

1) Will one drive be labeled as the primary ? I mean, is one of them
the target of each write operation, and the other gets written to after
the fact, or do they both get writtten simultanously ?

2) My intention is to treat one of them as a portable backup, swapping
it out with another every month or so, for security purposes. Is this
doable ? The scenario will be that yank one of them out, go to the
bank vault, swpa it out, I come back with the older (outdated) disk and
pop it into the RAID 1 array (of 2 drives)... then what ? Will the
system compare the two and realize that the new one has a lot of
catching up to do and sync up all the changes ? Am I dreaming or is
this the way it will behave ?

3) As a follow on to 2), it seems since RAID 1's purpose is for
failover, it should allow swapping out a bad drive with no loss of
uptime or data, so it seems I could do the same thing as a backup
rotation method. Correct ?

4) Due to what I describe above, I will have the second drive in a
removable tray - will I be able to hot swap it while the PC is running
?

5) How will I setup the above ? Through the disk management utilities
of the OS ? I know they will both be designated as Dynamic drives, but
that's where my understanding ends.

6) Last, is there any way to specify that only specific directories on
a drive are mirrored somewhere in the system (on the same OR different
drive) ? Likely this woud NOT be a function of the builtin RAID
controller, but some other utility/OS function.


Thanks much in advance...

Scott

 

[Dave]

I am not new to RAID in the IT world, but never set it up at home. In
the next month or two I will be building a new AMD X2 PC using either
an Abit or ASUS mobo, one the latest SLI boards which include RAID. I
am targeting RAID 1, as I am not that concerned about performance, but
very concerned about redundancy. Here are my questions:

1) Will one drive be labeled as the primary ? I mean, is one of them
the target of each write operation, and the other gets written to after
the fact, or do they both get writtten simultanously ?

2) My intention is to treat one of them as a portable backup, swapping
it out with another every month or so, for security purposes. Is this
doable ? The scenario will be that yank one of them out, go to the
bank vault, swpa it out, I come back with the older (outdated) disk and
pop it into the RAID 1 array (of 2 drives)... then what ? Will the
system compare the two and realize that the new one has a lot of
catching up to do and sync up all the changes ? Am I dreaming or is
this the way it will behave ?

3) As a follow on to 2), it seems since RAID 1's purpose is for
failover, it should allow swapping out a bad drive with no loss of
uptime or data, so it seems I could do the same thing as a backup
rotation method. Correct ?

4) Due to what I describe above, I will have the second drive in a
removable tray - will I be able to hot swap it while the PC is running
?

5) How will I setup the above ? Through the disk management utilities
of the OS ? I know they will both be designated as Dynamic drives, but
that's where my understanding ends.

6) Last, is there any way to specify that only specific directories on
a drive are mirrored somewhere in the system (on the same OR different
drive) ? Likely this woud NOT be a function of the builtin RAID
controller, but some other utility/OS function.


Thanks much in advance...

Scott

OK, what you are looking for is a 3rd hard drive to occupy the removeable
drive tray OR (smarter solution) a USB external drive enclosure for the 3rd.
Add Acronis True Image 9 for software. Done.

http://www.newegg.com/Product/Product.asp?Item=N82E16817201012
http://www.acronis.com/

You could use freeware synchback software to back up specific directories
(scheduled automatic backups, even). But True Image 9 will do that also,
and it will image your entire RAID array also. -Dave

 

[Maxx Pollare]

Reality folded in on itself, and somewhere the following words from
"ScottHW" appeared in history:

1) Will one drive be labeled as the primary?

No... Both drives will look like one drive as far as any OS cares;
it's only one drive visable in your computer. All normal disk writes
will be simultaneous, or appear to be at the same time, depending on
where the drives are connected.

2) My intention is to treat one of them as a portable backup,
swapping it out with another every month or so, for security
purposes. Is this doable?

Maybe... You may have to have both drives in the same style of
removable frame so they are both electricly identical.

The scenario will be that yank one of them out, go to the bank
vault, swpa it out, I come back with the older (outdated) disk
and pop it into the RAID 1 array (of 2 drives)... then what ?

Depending on the size of the disks, 2+ hours to rebuild the array.

Will the system compare the two and realize that the new one has
a lot of catching up to do and sync up all the changes?

No. That can only be done with a software based mirroring, and that's
often not as portable (accrost OS's installs), anywhere as fast, or
as synchronis as a hardware based array.

3) As a follow on to 2), it seems since RAID 1's purpose is for
failover, it should allow swapping out a bad drive with no loss of
uptime or data, so it seems I could do the same thing as a backup
rotation method. Correct?

Maybe (see answer to 2)...

4) Due to what I describe above, I will have the second drive in a
removable tray - will I be able to hot swap it while the PC is
running ?

Never... (when possable)

5) How will I setup the above? Through the disk management
utilities of the OS? I know they will both be designated as
Dynamic drives, but that's where my understanding ends.

http://www.pcstats.com/articleview.cfm?articleid=830&page=1

Or a similar page should help.

6) Last, is there any way to specify that only specific directories
on a drive are mirrored somewhere in the system (on the same OR
different drive)? Likely this woud NOT be a function of the builtin
RAID controller, but some other utility/OS function.

Bingo... Nail on the head...

Although the partitions on the RAID could be mouted as directories
on another drive with Windows XP, it's not the same as keeping an
archive of any given folder, but it works.

IF you realy need that fuction go with daves sugestion, and use
exturnal USB drives with your choice of syc software.

 

[ScottHW]

You recommend the USB external enclosure for portability reasons ? The
3rd drive will be swapped in and out of a safe deposit box (which
actually means I will have 2 of these "3rd" drives), so the extra space
of an enclosure makes that troublesome, and removing it even more so -
that's why I have been using a removable tray - takes up a lot less
space in the vault.

I am already using sync software, but was hoping for a real time mirror
operation onto the 3rd drive so I don't have to think about it - its
just there at any point in time. Maybe I am making this too
complicated.

Thanks for the input.

 

[ScottHW]

OK, what you are looking for is a 3rd hard drive to occupy the removeable
drive tray OR (smarter solution) a USB external drive enclosure for the
3rd.
Add Acronis True Image 9 for software. Done.

http://www.newegg.com/Product/Product.asp?Item=N82E16817201012
http://www.acronis.com/

You could use freeware synchback software to back up specific
directories
(scheduled automatic backups, even). But True Image 9 will do that
also,
and it will image your entire RAID array also. -Dave
<

Will True Image backup an entire physical drive verbatim, across all
partitions of any type ? In other words, a byte for byte image so I
effect an exact drive copy ?

 

[Dave]

Will True Image backup an entire physical drive verbatim, across all

partitions of any type ? In other words, a byte for byte image so I
effect an exact drive copy ?

It does have that option. I've never tried it, but I suspect it will work
great. I use it to image the primary active partition (C quite regularly,
on two different computers. And the restore function works fantastic. But
in creating the image, I've never checked off the box to image the entire
PHYSICAL drive, but it's there. -Dave