Host based mirroring and striped disks URGENT

[Adrian Sims_2]

Hi

We are copying from one DMX to another and are looking to use host based mirroring. Does anyone know if there are issues with striped disks if we follow this method please. if there are and we decide to build a config from fresh what is the quickest other method for copying the data (cpio etc)

Thanks

[Steven E. Protter]

Shalom,

The quickest method for copying data within the same system is cp -R

The quickest method for copying data between systems is:

scp -rp /home/* newsystem:/home

rcp will also work.

If you want to fully retain numeric permissions use cpio or tar, transfer the file and then unzip.

I don't really know what you mean by host based mirroring. The target system does not care how the system was striped or mirrored or pocadoted(joke) on the source system.

To give good advice concerning mirroing, I'd need to know what kind of systems are involved, what kind of disk, and how it was striped(lvm?) or mirrored(disk controller based or mirror/ux).

SEP

[RAC_1]

You can't to mirroring with LVM if lvols are created with -i and -I options. If they are not that way, you can safely do mirroring.

[Chan 007]

Hi Adrian,

You can do that host based one, but ensure that before spliting the DB & application is shutdown. This will take less outage than cpio based, cpio will need your application to be shutdown. But for mirroring you need to keep an eye on few parameters like max_pvs.

BTW what about srdf between two arrays? if you can do that you can back it up using symrdf commands? Only you need to shutdown while spliting them.

Chan

[Adrian Sims_2]

Hi Chan

We have MAX PE problems as well on 22 disks on one array. We are going from 30 to 60 gig luns so we are looking to move the data to other VG's and repair before the mirroring. The striping came up as an aside yesterday. I need to clear up if host-based-mirroring will work on striped disks

[rariasn]

Hi Adrian,

I use emc "symcli" tools

# symmir ; to copy to bcv's disk
# symrdf ; to copy to rdf's disk

Consult to emc support for other options to copy data between DMX cabines.

rgs,

[Marvin Strong]

I did a large migration last year from DMX to DMX and fixed a PE issue aswell. Sounds like what you are doing is similar.

My method was with both DMX attached to the host. I created the new vg's and had a script created by another admins who started the projected before me. That used cpio to copy the data between vg's, we ran 10 cpios concurrently.

Basicly with:
(cd /src; find . -xdev | cpio -pxdumv /dest &) >> src.log

Unfortunately with striping you cannot mirror. as I beleive was stated above. So even on the vg's that PE size was ok, we still used the cpio script. Of course this requires downtime. As you don't want these files being modified while you are copying them.

[Michael Steele_2]

Host based mirroring and striped disks or from host based mirroring to striped disks?

Raid 10 is mirroring and striped disks so you have to copy one tower / disk array to another.

If its mirroring to stripted disks then cpio from the file system level is all you need since data will be written to the disk without confusion and automatically converted. But don't do a PVMOVE which is below the file system level and maps from PE to PE. In this case the data configuration the mirrored PE will be different from the striped PE.