RE: data copy upon removal of drive string

In my thankfully limited experience in removing drives from ASPs, the
main thing is be patient.  It takes hours.

Is the EMC DASD in a separate ASP?  If so, it'll probably be faster to
back up the relative libraries and then restore them to the ESS.

If the DASD is not in a separate ASP, my advice would be:

0. GO SAVE/21 before you do anything.
1. Purge what you can.  Take the opportunity to clean up the box if you
can.  Everything you can remove is something less to have to move
around.  Don't forget the IFS; scan for *.LOG & *.log files from
WebSphere among others.
2. Reorg whatever PFs you can.  Again, it reduces the DASD in use and
thus the stuff it'll have to move.
3. Then add the new ESS disks.
4. Consider doing a STRASPBAL (probably using *CAPACITY) before removing
the EMC DASD to spread existing data onto the ESS disks.  Once the
de-install of the EMC commences, it should spread the data among all
other existing drives vs. mostly to the new ESS disks.
5. Remove all of the EMC disks at the same time.  It will be faster than
doing them individually.

To try and estimate further, we'll need more info:

- ASP config (number, size, and speed of drives)
- Controllers used
- Type of disk protection
- % full of the disks (are all 80% full like the EMCs?)

-----Original Message-----
From: McBride, Catherine [mailto:CMcbride@xxxxxxxxx] 
Sent: Tuesday, November 11, 2003 11:19 AM
To: 'midrange-l@xxxxxxxxxxxx'
Subject: data copy upon removal of drive string


Hello Midrange-L,
     We are moving from an EMC 5700 SAN to an IBM ESS 800.  Currently we
have 7 drives on the EMC that sensed as 9337's with a capacity of 8.5 gb
each.  Non-compressed, SCSI attached.  80% full. We'll be copying to the
ESS drives that are also SCSI attached by way of 'remove' on the EMC
string.  Do any of you have a way we might estimate how long copying the
data from the EMC to the ESS might take, per gigabyte?  Model 820 box.
I understand there's alot of variables like data transfer rate, fibre
versus SCSI, etc
etc, so "It depends".   But, even knowing how long other migrations took
at
other shops would give me something to go on.   If anyone's willing to
share
their experiences, we'd sure appreciate it.          
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