Doing a dd on a device goes through the cache, so in this case the cache can't be the problem. Doing a dd on a live system however will not work. With or without a cache the filesystem can change while you are doing the copy, which would result in a bad root on the new system.
I suspect that the errors you are getting are due to the target DASD not being formatted. Did you do a dasdfmt on the target volume? -----Original Message----- From: Linux on 390 Port [mailto:[EMAIL PROTECTED] Behalf Of van Sleeuwen, Berry Sent: Thursday, August 21, 2008 4:53 AM To: [email protected] Subject: Re: Root filesystem error switches to ReadOnly Mark, Hm, I even didn't think about cache and what it could do to not only files but also to the filesystem itself. And even if I did I'd have guessed it would only mess up a logfile that isn't in use on the target anyway. We would start in a new machine with an empty /var/log/messages and /var/log/warn for example. I think I'll start on a new machine to be used for resque and cloning so that we must run our cloning from a separate machine. Thanks, Berry. -----Original Message----- From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf Of Mark Perry Sent: donderdag 21 augustus 2008 13:27 To: [email protected] Subject: Re: Root filesystem error switches to ReadOnly van Sleeuwen, Berry wrote: > Hello Mark, > > I'll have to look into the flashcopy process but have not taken the time for it just yet. > > I guess one thing that would be wrong then is that I copy from the live system. So the source nlzlx920 is being copied from within the nlzlx920. But would that introduce IO errors on the target disks? If anything I'd expect to see errors during boot of the target guest. Either in a filesystemcheck or dmesg afterwards. Much like when you DDR a live VM and get a warmstartdata error when the target is IPLled. Perhaps a rethink of the process is in order. I guess a resque system would be an option. I do like to have a resque machine so I could also use that machine to do the cloning. > > As for other questions, I also assume I have the rights. No errors on that part. Same amount of cylinders. I have not yet ran the fsck on the source nor did I test it in a failsafe IPL of a new target. I dd with "dd bs=4096 if=$sDev of=$tDev" no other options. Haven't ran dd during the process by hand, other than a manual test to clone the first machine and to test the steps in the script. No erep or errors within the operator log. There is no error from the VM part. It's only within the linux. > > Regards, Berry. > Never clone a "live" Linux filesystem. Once the filesystem has been mounted the filesystem is cached in storage (as are updates) and the on disk filesystem is marked 'dirty". Stop the "master" linux system with a clean shutdown, and copy the disk using flashcopy or ddr if you prefer. This new copy is the "master" disk to be used for future copies. Reboot the Linux system and run an e2fsck on the new copy to ensure it is good. Then clone as you like ;-) mark ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 __________________________________________________________________________________________________ CONFIDENTIALITY NOTICE: This email from the State of California is for the sole use of the intended recipient and may contain confidential and privileged information. Any unauthorized review or use, including disclosure or distribution, is prohibited. If you are not the intended recipient, please contact the sender and destroy all copies of this email. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
