Mirroring Harddisk

[Daniel Schneider_3]

Hi all,
I have two equal Harddisks in a HP9000 A180 Server.
The First is the Main Disk and the second ??s unused.
Now I want to copy the first Disk to the second one once every Night to get a failover for this server.
To do this once a day is enough, because it is a development machine.
Has anybody some ideas to do this 'raw' copy?
Any Idea is very welcome!

Best Regards
Daniel

[Pete Randall · Accepted solution]

I'm not sure how successful this might be, but you could try to "dd" one disk to the other: "dd if=/dev/rdsk/c0t6d0 of=/dev/rdsk/c0t5d0 bs=1024k".
Try it and see if it's bootable.

The other option of course is to purchase the MirrorDisk-UX product and mirror each of the lvols on your root disk to your spare disk. That would be the preferred way.


Pete

[Donald Kok]

Hi Daniel,

I think you should make Pete's dd from single usermode. That way you are sure no files are open.

Greetzz
Donald

[harry d brown jr]

Mirror/Ux

and

make_tape_recovery's every night!

Mirror/ux = ~$1000.00
http://www.software.hp.com/cgi-bin/swdepot_parser.cgi/cgi/displayProductInfo.pl?productNumber=B2491BA

make_tape_recovery = $FREE.00
http://www.software.hp.com/products/IUX/download.html


live free or die
harry

[Gary Yu]

Something I'm not quite sure about, can you "split" a mirrored disk out, and use it as a boot disk on another server? (to clone a system)

EMC has a very cool product called BCV-Business Continous Volume, which you can Mirror and Split a volume at anytime, but I think it only works on its own disk array.

Back to Daniel's question, I think make_tape_recovery to the 2nd disk is a good choice.

thanks,
Gary

[Michael Duthie]

Daniel,

I would say either buy Mirror/UX or ignite to tape.

Gary,

Yes, you can split with LVM but it is logical volumes you split not disks. You could split the whole of VG00 and boot from it but the hardware on the second system would have to be identical to the 1st, to clone a system use Ignite/UX.

EMC BVC ia a hardware product, the HP equivalent is Business Copy on XP512, VA & EVA.

LVM Mirroring is a software product.

[Geoff Wild]

Use mirror/UX:

pvcreate -B /dev/rdsk/c3t6d0
vgextend /dev/vg00 /dev/dsk/c3t6d0
mkboot -l /dev/rdsk/c3t6d0
lvextend -m 1 /dev/vg00/lvol1 /dev/dsk/c3t6d0
lvextend -m 1 /dev/vg00/lvol2 /dev/dsk/c3t6d0
lvextend -m 1 /dev/vg00/lvol3 /dev/dsk/c3t6d0
/usr/sbin/lvlnboot -b /dev/vg00/lvol1
/usr/sbin/lvlnboot -s /dev/vg00/lvol2
/usr/sbin/lvlnboot -r /dev/vg00/lvol3

[Tim D Fulford]

dd , OK
Ignite - Excellent (bootable)

If you were to mount your other disk at /backup

What about fbackup. This would be very efficient. You could either fbackup one disk to the other.

fbackup -f /bacbuk/backup.fbk -0 -i /

or, probably most preferable of all, fbackup to tape.

ALTERNATIVELY... copy (cp)

cp -p /* /backup/.
cp -pr /usr/ /backup/.
: an so on :

NOTE I did NOT do cp -pr / /backup/. as this would be recursive!

just my 0.02???

[Jon Finley]

Most methods if done at init 3 with active users are going to give you a skewed image.

dd at single user will work, but now you're dealing with down time.

Mirror-UX with mutiple mirrors would give you a good recovery method (strip and rebuild to circulate a drive in and out).

Online JFS would allow you to build a snapshot filesystem for making backups.

And of course Ingite.

I've done a dd image at init 3, and could never get it to boot.

Another issue with dd, is that it will also copy over the bad block directory to the new disk. This could cause a panic condition later, if not cleared out with the HP utility bbdir.

Jon

[Daniel Schneider_3]

Thank you guys for all your great help!
So let me tell you about my experience with that.
First of all, I must tell you, that I'm searching a way without costs, so HP-Mirror is not the right one.
I tried out the dd-command last night as given from pete randall in the first answer.
This morning, I swapped the SCSI-ID's from the Harddisks and tried to boot - and it works!
I'm surprised and happy. That is an easy way to get fast system recover for a non productive machine.
Thank you all again.

Best regards
Daniel