# Boot SAN and Multipath



## armand (Sep 16, 2010)

Hello,

Our organization has acquired Dell Server 610 with one Dual Canal Qlogic QLE2462.

The server has been connected to the Storage Area Network (3Par) and I have installed FreeBSD 8.1 (amd64) on a LUN with the traditional UFS filesystem. I have created 3 partitions :


/
/var
swap

The Boot San is working perfectly.

I have activated geom_multipath on the boot San disk.


```
srvnas05# gmultipath list
Geom name: FREEBSD
Providers:
1. Name: multipath/FREEBSD
   Mediasize: 156766305792 (146G)
   Sectorsize: 512
   Mode: r1w1e3
Consumers:
1. Name: da0
   Mediasize: 156766306304 (146G)
   Sectorsize: 512
   Mode: r1w1e3
2. Name: da2
   Mediasize: 156766306304 (146G)
   Sectorsize: 512
   Mode: r1w1e3
```

After I have activated geom_multipath directly at boot :

```
srvnas05# cat /boot/loader.conf
geom_multipath_load="YES"
```


and I have tried to mount the "/var" partition at boot via the geom_multipath device by changing the /etc/fstab from :


```
/dev/da0s1d             /var            ufs     rw              2       2
```

to 

```
/dev/multipath/FREEBSDs1d     /var            ufs     rw              2       2
```

but after reboot i have this message :


```
/dev/multipath/FREEBSDs1d: NO WRITE ACCESS
/dev/multipath/FREEBSDs1d: UNEXPECTED INCONSITENCY; run fsck MANUALLY
THE FOLLOWING FILE SYSTEM HAD AN UNEXPECTED INCONSISTENCY:
      ufs:/dev/multipath/FREEBSDs1d (/var)
```

My question is : is it possible to have write access on FS like / or /var at boot via the geom_multipath device ?

Thank you for your help.


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## User23 (Sep 17, 2010)

You need to label it. Please read the manpage.

http://www.FreeBSD.org/cgi/man.cgi?...ion=0&manpath=FreeBSD+8.1-RELEASE&format=html


```
gmultipath label [-hv] name prov ...

label    Label the given underlying device with the specified name.  The
	      kernel module geom_multipath.ko will be loaded if it is not
	      loaded already.
```


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## armand (Sep 20, 2010)

My device are labelled. I used the "gmultipath label" to create my multipath device. I don't think that you can see gmultipath devices without having previously labelled some devices.


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## AndyUKG (Sep 21, 2010)

Interesting prob (for me) Ive not had to use FreeBSD with SAN disk yet.



			
				armand said:
			
		

> Hello,
> 
> The Boot San is working perfectly.



So you can boot from SAN without problems without geom multipath? 



			
				armand said:
			
		

> My question is : is it possible to have write access on FS like / or /var at boot via the geom_multipath device ?
> 
> Thank you for your help.



So I dont have experience to give you an answer to this question, but how about a hack/work around... Can you boot with the original fstab entry, and then just have a script to mount the geom multipath device after boot? Obviously that has the issue that you cannot boot if the primary path is down, but it should then withstand a path failure when the system is up and running....?


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## armand (Sep 23, 2010)

AndyUKG said:
			
		

> So you can boot from SAN without problems without geom multipath?



Yes it is working perfectly.



			
				AndyUKG said:
			
		

> So I dont have experience to give you an answer to this question, but how about a hack/work around... Can you boot with the original fstab entry, and then just have a script to mount the geom multipath device after boot? Obviously that has the issue that you cannot boot if the primary path is down, but it should then withstand a path failure when the system is up and running....?



It could be a solution, I'm going to try this.


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