topic Re: RE : help data transfer in Operating System - HP-UX

RE : help data transfer

Vincent_5 — Wed, 15 Feb 2006 01:25:26 GMT

Hi Guys,
Can anyone advice how can I perform a data transfer from a b2000 workstation with a DS 2100 connected and a DS2300 connected via different scsi card. I understand that I can used dd to copy or use cp. The harddisk size is 72GB mirror two vg group. Which one is fster and how much time is reqiure. Also, can provide me with the dd command.

is it something like

dd if=/dev/dsk/c0t0d0 of=/dev/dsk/c1t0d0 block size 1024
assume c0t0d0 is the source and c1t0d0 is the target.

Regards
Vincent

Re: RE : help data transfer

Sivakumar TS — Wed, 15 Feb 2006 01:51:57 GMT

Hi,

"dd" is just block-to-block coppying of FULLDISK, ie.. irrespective of the used/data area it would take the same time to complete the operation.

Based on the used space you can decide whcih command to use, if your used/data area is less then it is better to use the "cp" itself.

pls use -p option with "cp" command, this will preserve the permissions too.

With Regards,

Siva.

Re: RE : help data transfer

Muthukumar_5 — Wed, 15 Feb 2006 01:56:01 GMT

Use cp command with following options for this requirement as,

cp -pS -r -e warn /directory

It is safer one.

--
Muthu

Re: RE : help data transfer

Arunvijai_4 — Wed, 15 Feb 2006 02:07:08 GMT

Hi Vincent,

You can use "cp" or "mv" to do this.

-Arun

Re: RE : help data transfer

Devender Khatana — Wed, 15 Feb 2006 02:17:55 GMT

Hi,

If you have mirror-Ux installed then the best way would be to extend the mirror to the new devices and then reduce it from the old devices. This will be slightly slow then the dd but will be the good option if disks sizes are slightly different.

Also cpio is an option. Create new VG on new disks and mount it on similar paths say if old is /data then at datanew, /data1 at /data1new and so on

Then
#pwd
/data
#find ./ -name "*" -print|cpio -pdmv /datanew

Repeat for other volumes.
In the end unmount original file systems and mount new file systems at that path. The benefit of this approach will be that you can resize / reconfigure VG and file systems. The downcome is that the application should be stopped during copy whereas earlier two methods do not require that and can achive the whole process with some compromise with performance.

HTH,
Devender

Re: RE : help data transfer

Vincent_5 — Wed, 15 Feb 2006 07:59:52 GMT

Hi Devender Khatana,
Thanks for the info, lets assume that i have 2x 72GB disk mirror on vg01 and another 2x72GB disk mirror on vg02 . I intent to use 2 x 300GB newly add disk for vg01 and another 2 x300GB for vg02. Please advice on the steps how can I extend the mirror copies to the 300GB with the data intact and than reduce the old disk. Thanks.
Note, there isn't any backup available .

Regards
Vincent

Re: RE : help data transfer

Geoff Wild — Wed, 15 Feb 2006 10:46:01 GMT

I have always found that vxdump/vxrestore to be the fastest...

Mount the "old" lvol to say /zmnt and the new disk to the new mount.

vxdump -0 -f - -s 1000000 -b 16 /zmnt/oracle | (cd /oracle ; vxrestore rf -)

Rgds...Geoff

Re: RE : help data transfer

Devender Khatana — Thu, 16 Feb 2006 01:03:30 GMT

Hi,

As there is quite a lot difference in the disk sizes for this method to be adoptive you will have to find out if your existing VGs support these disks. Find out PE_Size & MAX_PE_PER_PV from the output of

#vgdisplay -v /dev/vg01
#vgdisplay -v /dev/vg02

The multiplication of the parameters will give you the largest size of indivisual disk in these VG. If this is more than the size of new disks then you can add them in current VG.

Also you should have an option of physically connecting new four disks simultaneously with existing disks if the option for connecting two new disk is there than this will also work.

HTH,
Devender

Re: RE : help data transfer

Mark Ellzey — Thu, 16 Feb 2006 11:32:50 GMT

Vincent,

Regardless of the method you use, I would first make sure I had a good backup of the data before trying to copy it to another disk.

Regards,
Mark