HPE EVA Storage

MSA1500, QLogic HBA and SLES10 SP3

 
toomas_aas
Frequent Advisor

MSA1500, QLogic HBA and SLES10 SP3

Hello!

I've read from several 'release notes' that starting with SLES10 SP3 the QLogic driver based failover is no longer supported and native drivers with device-mapper multipathing should be used instead.

I have MSA1500 in active/passive configuration, to which several servers are attached: two SLES10SP2, one Netware 6.5 and one Windows 2003.

If my understanding is correct, device mapper canot be used with active/passive array.

So, it seems there is no way for me to upgrade my SLES10 servers from SP2 to SP3. Is it certain that the QLogic driver based failover no longer works, or is it just 'not officially supported'? Does anyone here have real-life experience with this?
7 REPLIES 7
skt_skt
Honored Contributor

Re: MSA1500, QLogic HBA and SLES10 SP3

who said DM cannot be used with active/passive array.

atleast i have EMC Clariion(active/passive) working with RHEL
toomas_aas
Frequent Advisor

Re: MSA1500, QLogic HBA and SLES10 SP3

I have here a document titled "Device Mapper Multipath Configuration Guide for HP StorageWorks Arrays", second edition, december 2006. On page 13 under a list of supported hardware and software, it says:

"Note: Does not support Active-Passive Storage Arrays"

There was also a note of similar effect in the HP support notice titled "HP StorageWorks 1500cs Modular Smart Array - NOTICE: HP StorageWorks Device Mapper and In-box Linux HBA Driver Support Changes - Update - c01604888 - HP Business Support Center", which is currently unaccessible, but only a couple of days ago was online at http://lnk.nu/h20000.www2.hp.com/12m9.jsp

When our MSA1500 was initially set up by a HP partner, they used device mapper but after they left the site I discovered that failover did not work. When I discussed this issue with them, they were surprised but admitted that they had no prior experience with my specific type of setup. I transferred things to QLogic driver based failover and everything has worked smoothly ever since.

If my information turns out to be outdated, that'd be great news.
toomas_aas
Frequent Advisor

Re: MSA1500, QLogic HBA and SLES10 SP3

It seems to work, indeed.

First I tested having a working SLES10SP2 box with QLogic driver failover and upgrading that to SLES10SP3. The result was a non-working configuration - even though the LUN is seen by OS as /dev/sda, attempts to mount existing filesystem on that LUN fail with error "special device /dev/sda1 is missing".

After that, I uninstalled the HP QLogic driver, so the system switched back to using the driver that is included with SLES. Now I could mount the filesystem from the LUN device, but of course I had no failover.

After some head-scratching, I managed to configure multipath so that I could also access the LUN via multipathed device /dev/disk/by-name/areallylongname. I did not install the "HP DM-MPIO Enablement Kit" or whatsitcalled, I used just the pieces that come with SLES. I can now pull the cable from the active MSA controller, and I/O does successfully fail over to the other controller.

For those interested, below is the "device" section of my multipath.conf. Rest of multipath.conf I left as defaults.

device {
vendor "COMPAQ"
product "MSA*"
getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
prio hp_sw
hardware_handler "1 hp_sw"
path_selector "round-robin 0"
path_grouping_policy group_by_prio
failback immediate
rr_weight uniform
no_path_retry 18
rr_min_io 100
path_checker hp_sw
}
skt_skt
Honored Contributor

Re: MSA1500, QLogic HBA and SLES10 SP3

also you need to configure filter ( both accept and reject)with /etc/lvm/lvm.conf assuming u r using LVM
toomas_aas
Frequent Advisor

Re: MSA1500, QLogic HBA and SLES10 SP3

In this test I wasn't using LVM, but yes, on my live server I'll need to take care of that. I wonder, if the LVM physical volume is currently (using SLES10SP2 and QLogic driver failover) seen as /dev/sda, and after reconfiguring for DM-MPIO it is /dev/disk/by-name/something, can that cause problems? I guess another test is in order.
skt_skt
Honored Contributor

Re: MSA1500, QLogic HBA and SLES10 SP3

r u booting from SAN?
toomas_aas
Frequent Advisor

Re: MSA1500, QLogic HBA and SLES10 SP3

No, the OS is on local disks, only the application data is on SAN.