[dm-devel] Resizing multipath maps: reload ioctl failed: Invalidargument

[Domenico Viggiani]

> -----Original Message-----
> From: dm-devel-bounces at redhat.com 
> [mailto:dm-devel-bounces at redhat.com] On Behalf Of Aaron Bergstralh
> Sent: Wednesday, October 24, 2007 5:50 PM
> 
> I have used the following in the past when I needed to resize 
> online. I have only tested this for the round robin selector 
> but a similar method could also work for other selectors.
> 
> #Started with the following dm table
> dmsetup table m500i_A_lun_4
> 0 157287936 multipath 0 0 1 1 round-robin 0 2 1 8:80 100 8:160 100
> 
> ###Used the following in a script to complete the resize 
> dmsetup suspend m500i_A_lun_4
> 
> #Reload with one device removed and old size dmsetup load 
> m500i_A_lun_4 <<EOF 0 157287936 multipath 0 0 1 1 round-robin 
> 0 1 1 8:80 100 EOF dmsetup resume m500i_A_lun_4 dmsetup 
> suspend m500i_A_lun_4
> 
> #Reload with one device removed for all other devices dmsetup 
> load m500i_A_lun_4 <<EOF 0 157287936 multipath 0 0 1 1 
> round-robin 0 1 1 8:160 100 EOF dmsetup resume m500i_A_lun_4 
> dmsetup suspend m500i_A_lun_4
> 
> #Reload with all devices and new size
> dmsetup load m500i_A_lun_4 <<EOF
> 0 209717248 multipath 0 0 1 1 round-robin 0 2 1 8:80 100 
> 8:160 100 EOF dmsetup resume m500i_A_lun_4
> 
> After the last step everything is able to see the new device 
> size. I know this isn't an ideal solution but it might be 
> useful for some people.

I have an EMC Clariion with four paths (two active and two passive):

# multipath -ll

360060160eb2417004412f146416bdc11
[size=20 GB][features="0"][hwhandler="1 emc"]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:2:200 sdb 8:16  [active][ready]
 \_ 1:0:4:200 sdk 8:160 [active][ready]
\_ round-robin 0 [enabled]
 \_ 0:0:3:200 sde 8:64  [active][ready]
 \_ 1:0:3:200 sdh 8:112 [active][ready]

# dmsetup table 360060160eb2417004412f146416bdc11
0 41943040 multipath 0 1 emc 2 1 round-robin 0 2 1 8:16 100 8:160 100
round-robin 0 2 1 8:64 100 8:112 100 

What are the exact order of remove/reload in this case?
I'd like to understand the logic!

Thanks again
--
DV