Ubuntu Server 14.04 - iSCSI and Multipath

[ubern00b]

Hi all

I have been given a project at work that is some what out of my ball park. I need to install Ubuntu Server and attach an iSCSI LUN to it for use with Percona (MySQL) Server.

So I have Ubuntu installed, I have the iSCSI LUN presented to the server. Multipathing is installed and working however I am still seeing 8 disk drives for the presented iSCSI LUN. I don't really know what I am meant to be seeing as this is all new to me. I installed the server with LVM too, which I am trying to get my head around.

Anyway, any guidance for me here perhaps? Output of cat /proc/partitions:

root@NDC-LMS-PRC-S01:~# cat /proc/partitions
major minor #blocks name

8 0 143338560 sda
8 1 249856 sda1
8 2 1 sda2
8 5 143088128 sda5
252 0 9764864 dm-0
252 1 5345280 dm-1
252 2 127950848 dm-2
8 16 52428800 sdb
8 32 52428800 sdc
8 48 52428800 sdd
8 80 52428800 sdf
8 64 52428800 sde
8 96 52428800 sdg
8 112 52428800 sdh
8 128 52428800 sdi
252 3 52428800 dm-3
root@NDC-LMS-PRC-S01:~#

sdb through i is what I am sure I shouldn't be seeing? dm-3 is the LVM map for the iSCSI LUN?

Thanks for your help, really don't know what I am doing here... as you can probably tell.

 

[ubern00b]

I created a partition on the disk and now it seems I have 16 instances of the disk showing? 8 physical and 8 partitions? Also 2 LVM mappings?

root@NDC-LMS-PRC-S01:~# cat /proc/partitions
major minor #blocks name

8 0 143338560 sda
8 1 249856 sda1
8 2 1 sda2
8 5 143088128 sda5
252 0 9764864 dm-0
252 1 5345280 dm-1
252 2 127950848 dm-2
8 16 52428800 sdb
8 17 52424704 sdb1
8 48 52428800 sdd
8 49 52424704 sdd1
8 32 52428800 sdc
8 33 52424704 sdc1
8 112 52428800 sdh
8 113 52424704 sdh1
8 80 52428800 sdf
8 81 52424704 sdf1
8 96 52428800 sdg
8 97 52424704 sdg1
8 64 52428800 sde
8 65 52424704 sde1
8 128 52428800 sdi
8 129 52424704 sdi1
252 3 52428800 dm-3
252 4 52424704 dm-4

 

[ubern00b]

Whats the output of multipath -ll ?

root@NDC-LMS-PRC-S01:~# multipath -ll
Error: : Inappropriate ioctl for device
cciss TUR failed in CCISS_GETLUNINFO: Inappropriate ioctl for device
PureStorage (3624a9370931147961ad4ca080001102d) dm-3 PURE ,FlashArray
size=50G features='0' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=1 status=active
|- 1:0:0:1 sdb 8:16 active ready running
|- 2:0:0:1 sdc 8:32 active ready running
|- 3:0:0:1 sdd 8:48 active ready running
|- 4:0:0:1 sde 8:64 active ready running
|- 5:0:0:1 sdf 8:80 active ready running
|- 6:0:0:1 sdg 8:96 active ready running
|- 7:0:0:1 sdi 8:128 active ready running
`- 8:0:0:1 sdh 8:112 active ready running
root@NDC-LMS-PRC-S01:~#

 

[ubern00b]

Thank you for all your help, everything you have said, I have pretty much done.

I got the multipath.conf settings from my vendor (Pure Storage) and applied them. I still get the ioctl error. I blacklisted everything from multipath apart from the WWID of the SAN. Still errors for ioctl.

However, everything is working. I am using the friendly name I specified to mount the storage. I moved the MySQL data onto the storage and gave it a couple of reboots and made sure it came back up and everything *seems* ok. I guess I will find out at some point

Again, thank you for taking the time with me