mirroring root problem 2

[gallows]

We are running Solaris 9 and I am using Suns SDS.
Here is what I have done so far. Actually, I did the
below steps for each slice (3,4,5,6) minus the metaroot.
When I try to attach the mirror I get the error.

# metainit -f d10 1 1 /dev/dsk/c2t0d0s0
d10: Concat/Stripe is setup
# metainit -f d20 1 1 /dev/dsk/c2t1d0s0
d20: Concat/Stripe is setup
# metainit d0 -m d10
d0: Mirror is setup
# metaroot d0
# metattach d0 d20
metattach: syshost01: c2t0d0s0: is mounted on /

Thanks,
Gallows

 

[mrn]

See

http://www.manucomp.com/solaris_tips/solstice_disk_suite.html

alternative method

http://www.sun.com/bigadmin/content/submitted/svm_mirroring.html

Mike

"A foolproof method for sculpting an elephant: first, get a huge block of marble, then you chip away everything that doesn't look like an elephant."

http://www.airport-parking-site.co.uk/

 

[gallows]

I forgot to mention that c2t0d0s0 is the good disk and
I am trying to mirror to c2t1d0s0. Also, I did the prtvtoc so both disks are identical and I created the metadbs.

Gallows

 

[WhiteVolg]

You'll have to boot of the d0 before you can attach the mirror (d20)
so after the metaroot., reboot, then SDS has control of the mirror and it really is mounted as root.. then you can attach the backside of the mirror

 

[daFranze]

exactly as whitevolg writes; you cannot mirror as long as you don't write to d0 but c2t0d0s0, all you would get is an inconsistant Volume, if you write to the submirror not to the mirror(root).

Best Regards, Franz
--
UNIX System Manager from Munich, Germany

 

[gallows]

Thanks Mike - good docs.

Thanks WhiteVolg - I was trying to get away with not rebooting. I could have sworn I have done this before without rebooting. Anyway, I locked fs, rebooted and mirror
is fine.

Thanks Franz. I guess the inconsistant Volume is what I ended up with before if I did indeed successfuly mirror without rebooting.

regards,
gallows

 

[kHz]

SVM isn't the best volume manager. AIX has allowed mirroring/unmirroring on-the-fly from 3.2.5. It is inconceivable to me that Sun cannot incorporate that into the OS.

 

[daFranze]

I don't know the AIX Version of a logical volume manager, but I recently changed from Sun to hp. SVM is a realy easy to understand and simple constructed volume manager, maybe THIS is the reason why they do not add stuff like that: it would change it into a much more complex thing. If you want the complex thing on Sun/Solaris you could use VxVM, but AFAIK Veritas does the reboot, too.

Best Regards, Franz
--
UNIX System Manager from Munich, Germany

 

[daFranze]

have you had a look at ZFS, does it neet the reboot or is it a "on the fly" mirroring utility

Best Regards, Franz
--
UNIX System Manager from Munich, Germany

 

[kHz]

Solaris SVM is simple, that is true, and you are right that it would change the complexity of the OS and would have to be added into the OS as code. Right now SVM is installed as a half-dozen packages and to add AIX LVM capability would probably require an OS re-write.

FreeBSD has the same type of mirroring capability as Solaris and requires a reboot. It seems AIX is the only Unix variant that manages to mirror/unmirror root (and all volumes) on-the-fly.

I have installed OpenSolaris (coined version 11) on a spare Sun Blade 100 and attached a spare disk array so I could try zfs. zfs IS nice. I cannot wait until they add zfs into a Solaris 10 update (whenever that is).

To create a file system 'zpool create testpool' then 'zfs create testpool/testfs' and viola! done! No changing /etc/vfstab, or mount/unmount the file systems. You can create mirrors easily too. I have read that you can use zfs for boot, though it isn't recommended. So it seems they still want ufs used for your boot file systems. Maybe that will change in the future, but not right now. File systems grow and shrink based on the pool size and you can cap a file system using the quota argument for zfs.

But adding on-the-fly mirroring would change the very nature of the OS and traditional Unix, I guess. I have no problem using SVM but I just hate booting to add the root mirror and reboot the remove it.

 

[WhiteVolg]

They can they do, but it's buggy as all get out and while it works 90% of the time.. even I'm not willing to give out the secret code to do it .. 10% failure risk is too much fo root.
But if you really want to dig for it.. man mount and search for remount