Fssnap on a Read-Only mounted volume?

Hello,
Is it possible to create a snapshot of a volume that is mounted read only ?
My guess is that it isn't...
Here is the scenario.
I have a mail server who's primary /mail parition is a volume on our new iSCSI SAN.
I have a backup server who mounts the same SAN volume read only.
I want to let the backup server backup that /mail volume to another volume, or to tape however...
In the past, when I attempt to perform a regular ufsdump w/o any fssnap I often run into errors and the dump is inconsistent.
DUMP: bread: dev_seek error: Error 0
DUMP: Warning - block 1922882290 is beyond the end of `/dev/md/rdsk/d20'
I'm finding this to still be the case, even though the volume is on the SAN and is mounted read only.
Are those errors indicitative of a major problem or are they simply due to the fact that the volume is actively being written to and read from?
From the mail server, when I run ufsdump after running fssnap on the /mail volume, I don't see these errors, however the load on the mail server severely increases to the point where users begin to experience problems and slowdowns.
From the backup server, if I can fssnap that read-only /mail SAN /volume then perhaps I can get reliable backups?
Any suggestions would be appreciated.
Thanks,
--Raf

Here is a process I use all the time. And Yes you can fssnap a live system.
This artical is for x86 but you can adjust it to work for sparc.
http://solaris-x86.org/documents/tutorials/jsrestore.mhtml

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Our Xsan volume is going nasty
if any client tries to write on it , the xsan would
crash and disconnect on all clients
only way to bring it back is to shutdown all machines
and power on again
it works fine when the volume is mounted as read only
though , so now I have a volume I can only read from
, but can't write to
any one had this happening before ? any idea what
might be causing it ?
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Message was edited by: HeatherK

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Pondini wrote:
odysseus wrote:
This is a weird story. My wife has a PowerBook G4/1.33 GHz that she uses in clamshell mode with a 20" Cinema Display. One day under OS X 10.5.6, her Time Machine backups (to a networked 500 GB Time Capsule) failed with the error: Backup failed with error: The target volume is read-only. So I upgraded her to 10.5.7 and erased the sparseimage file, starting a new Time Machine backup. And it just happened again.
Try repairing the sparse bundle, per #A5 of the Time Machine - Troubleshooting *User Tip,* also at the top of this forum.
I've tried this before, but it can't be repaired, because it can't be mounted.
Any idea how this sort of problem arises? My wife was doing something at her computer when the Time Machine error occurred.
One possibility is, the HD in the Time Capsule is beginning to fail (all HDs fail, sooner or later).
I'm backing up to my own sparseimage bundle just fine.
Please don't advise us to upgrade to 10.5.8, because her PowerBook freezes not infrequently with any OS later than 10.5.6, and I was just about to downgrade her from 10.5.7 to 10.5.6.
Those two things may be related. Whatever's going wrong may very well be what's corrupting the backups.
I'd recommend finding out what's wrong with the Powerbook. It's impossible to tell, of course, but that may be the root of the problem.
There's a problem with PowerBooks and Cinema Displays. I've posted a lot about this. Even after a motherboard replacement, my PowerBook G4/1.67 GHz had freezes, and eventually Apple gave me a MacBook Pro, but I think there's a failure involving hardware/software design.
If you haven't yet, I'd start by dong a +*Verify Disk+* on it's internal HD (also per #A5);
That checks out fine.
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Fssnap on a Read-Only mounted volume?

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