I've installed Solaris 10 update 6 on a machine but it is not working 
very well at all for me. See the thread 'Help - Blade 2000 VERY sick 
after upgrade to S10 u6.' I've had

1) USB disk appears to have failed.
2) SCSI disk appears to be failing.
3) SunPCi card not working properly - probably a result of the disk 
issue, but I am begging to think it might be something else.


Perhaps more out of desperation than anything else, I'm seriously 
thinking of moving doing a fresh install with Solaris 10 update 4, which 
worked fine. The problem is, I have upgraded the ZFS version using

# zfs upgrade

IIRC, the ZFS version when from 4 to 10.

According to:

http://docs.sun.com/app/docs/doc/817-2271/gffys?a=view

"File systems that are upgraded and any streams created from those 
upgraded file systems by the zfs send command are not accessible on 
systems that are running older software releases."


Is there a way I can make the data on the disk readable and writable 
under Solaris 10 update 4, without destroying the data? I've got a 
couple more disks on order, so I could use one as UFS, and move the data 
via a UFS partition.

This might be a waste of time, but I have reports of hardware errors 
that only occured after upgrading the operating system.

Dave wrote:
> 
> Is there a way I can make the data on the disk readable and writable
> under Solaris 10 update 4, without destroying the data? I've got a
> couple more disks on order, so I could use one as UFS, and move the data
> via a UFS partition.
> 
Not without copying the data.  You upgrade a pool, but not downgrade.

If you gave spare disks, you can create a version 1 pool and filesystems
with version=1 and copy to that.  This should be readable from an older
release (I've created version 1 filesystems on update 6 and sent them to
update 5).  Check first by booting from the old install media and
importing the pool.

> This might be a waste of time, but I have reports of hardware errors
> that only occured after upgrading the operating system.

You might have flushed out a latent problem.

This tale of woe is a good advert for Live Upgrade!

-- 
Ian Collins

Ian Collins wrote:
> Dave wrote:
>> Is there a way I can make the data on the disk readable and writable
>> under Solaris 10 update 4, without destroying the data? I've got a
>> couple more disks on order, so I could use one as UFS, and move the data
>> via a UFS partition.
>>
> Not without copying the data.  You upgrade a pool, but not downgrade.

I thought that might be the case.

> If you gave spare disks, you can create a version 1 pool and filesystems
> with version=1 and copy to that.  This should be readable from an older
> release (I've created version 1 filesystems on update 6 and sent them to
> update 5).  Check first by booting from the old install media and
> importing the pool.


Thank you. I was going to use a UFS file system, but I can see ZFS with 
version=1 will be better. I might in fact use version 4, as that is what 
was used on the original system.

>> This might be a waste of time, but I have reports of hardware errors
>> that only occured after upgrading the operating system.
> 
> You might have flushed out a latent problem.

Perhaps.

I've ordered a couple of 1 TB USB drives (new) from Amazon, and a used 
147 GB FC-AL disk from eBay. I've also got a couple of spare 73 GB FC-AL 
disks, which will do for some basic tests, but are a bit too small for 
any long term use.

Hopefully I can sort this out pretty soon.

> This tale of woe is a good advert for Live Upgrade!


Yes, very true.

I did try a live upgrade some time back, but the installer wanted to 
repartition the disks, so it insisted on backing them up. I can't see 
why, as the root file system was 19 GB. I had no idea how much space it 
needed for the backup, but it was quite possibly the whole of a 147 GB 
disk, which I did not have spare capacity to back up again. Hence a 
fresh install, but which seems to have given me a few headaches.

dave