In my previous post, I wrote about my quest to identify a disk presented by the Dell server itself. At the end of the post, I mentioned that I should be able to resume with creating a LVM volume on the new disk. LVM stands for Logical Volume Management. There is a good tutorial available at this page if you’re interested in – How To Use LVM To Manage Storage Devices on Ubuntu 16.04.
Well, it turned out it wasn’t as straight forward as I had anticipated. The disk which I wanted to manage using LVM is /dev/sdb. First I tried to create physical volume on it using the usual command:
# pvcreate /dev/sdb
I wasn’t able to do that. It reported that ”/dev/sdb” wasn’t available. However, it was there when I listed the device: ls /dev/sdb. So what could have been the issue? Thanks to my coworkers, the problem was that someone the /dev/sdb device is reported as a multipath disk(?). I should have noticed this in the previous post when I listed it using the multipath command.
# multipath -ll
...
mpathg (361866da0770b210021fb3b86ab7cff72) dm-6 DELL ,PERC H730P Mini
size=3.6T features='0' hwhandler='0' wp=rw
`-+- policy='service-time 0' prio=1 status=active
`- 0:2:1:0 sdb 8:16 active ready running
So the solution is to black list the “PERC H730P Mini” raid controller. This could be easily done by updating /etc/multipath.conf:
blacklist {
device {
vendor "*"
product "PERC H730P Mini"
}
}
Then restart multipathd.service. I think I may need to reboot the server for the change to take effect. Finally, I was able to create a physical volume (PV) on /dev/sdb.
As the previous post, just when I’m about to click Publish for this post I found some interesting information about Blacklisting the local disk. One of them is to identify the vendor and product. There’s a command for that – lsscsi.
# lsscsi
[0:2:0:0] disk DELL PERC H730P Mini 4.26 /dev/sda
[0:2:1:0] disk DELL PERC H730P Mini 4.26 /dev/sdb
[5:0:0:0] disk DELL MD36xxf 0820 /dev/sdc
[5:0:0:1] disk DELL MD36xxf 0820 /dev/sdd
[5:0:0:31] disk DELL Universal Xport 0820 -
[5:0:1:0] disk DELL MD36xxf 0820 /dev/sde
[5:0:1:1] disk DELL MD36xxf 0820 /dev/sdf
[5:0:1:31] disk DELL Universal Xport 0820 -
[5:0:2:0] disk Lenovo DS4200 G250 /dev/sdh
[5:0:2:1] disk Lenovo DS4200 G250 /dev/sdj
[5:0:3:0] disk Lenovo DS4200 G250 /dev/sdk
[5:0:3:1] disk Lenovo DS4200 G250 /dev/sdm
[11:0:0:0] cd/dvd HL-DT-ST DVD+-RW GTA0N A3C0 /dev/sr0
[12:0:0:0] disk DELL MD36xxf 0820 /dev/sdg
[12:0:0:1] disk DELL MD36xxf 0820 /dev/sdi
[12:0:0:31] disk DELL Universal Xport 0820 -
[12:0:1:0] disk DELL MD36xxf 0820 /dev/sdl
[12:0:1:1] disk DELL MD36xxf 0820 /dev/sdn
[12:0:1:31] disk DELL Universal Xport 0820 -
[12:0:2:0] disk Lenovo DS4200 G250 /dev/sdo
[12:0:2:1] disk Lenovo DS4200 G250 /dev/sdp
[12:0:3:0] disk Lenovo DS4200 G250 /dev/sdq
[12:0:3:1] disk Lenovo DS4200 G250 /dev/sdr
In my case, I need to black list the “PERC H730P Mini”, or just “PERC*”.