[rescue] Mounting and Dumping

Clayton Wheeler csw at thirdshoe.net
Tue Jan 13 21:17:29 CST 2004

On Jan 13, 2004, at 4:56 PM, Janet L. Campbell wrote:

> On Tue, 13 Jan 2004, Sheldon T. Hall wrote:
>> 4)  What's a fellow to do?
> Well, fssnap is quite nifty.  It solves this problem nicely.

Hear, hear. I run my backups using ufsdump and fssnap; I have a shell 
script that creates the snapshot device, dumps it, and destroys the 
snapshot. It is here:


However, fssnap was introduced in one of the feature releases of 
Solaris 8, as I recall. It is definitely in Solaris 9, but if you're 
running Solaris 7 you're probably out of luck there. Can you upgrade? I 
think I recall someone on here saying that Solaris 9 actually ran 
better than the previous few versions on old hardware. It does fine on 
my SS20, at least. I haven't tried Solaris on my LX or Classic.

As Janet said, dumping quiescent filesystems works fine; fssnap doesn't 
work for / or /var, and I just dump them directly. Using fssnap really 
comes in handy for backing up the home directories on my file server, 
though, since they're basically always in use.

>> I have separate filesystems for /, /usr, /var, /users (everyone's home
>> directory), etc., but they are all on one disk.  In running a test, it
>> sounded like the Classic wasn't keeping up with the DLT drive.  Would
>> putting the DLT on the the SunSwift card's SCSI bus help that?

I think "iostat -ncx 10" will show you where the bottleneck is. (I'm no 
Solaris tuning ninja, though, so take this with a grain of salt.) It 
will show you a %b column for each device, indicating the percentage of 
time the device is busy, as well as a CPU usage header indicating user, 
system, I/O wait, and idle time. N.B. ignore the first screen of 

If the disk or the tape device is 100% busy, you've presumably got a 
bottleneck with that device. If neither of those shows 100%, but CPU 
system time is maxed out, a bigger box might be in order. If you don't 
see any of those things, perhaps that would mean SCSI bus contention, 
and putting the DLT on your SunSwift might be what you need.


Clayton Wheeler
csw at thirdshoe.net

More information about the rescue mailing list