[CentOS] filesystem mounting fails at boot

Sat Oct 10 18:41:26 UTC 2015
Imre Gergely <gimre at narancs.net>

On 10/10/2015 05:03 PM, Barry Brimer wrote:
> On October 10, 2015 8:34:11 AM CDT, Imre Gergely <gimre at narancs.net> wrote:
>> _netdev
>>              The filesystem resides on a device that requires network
>> access (used to prevent the system from attempting to mount these
>> filesystems until the network has been enabled on the system).
>> This device is not a network device (this a SAN not a NAS). To the OS
>> it
>> looks like a normal SCSI attached device, it's /dev/sdb. In the blade
>> there is a HBA (Qlogic) card, and it's connected through FiberChannel.
>> If I understand these terms correctly, it has nothing to do with the
>> network.
>> On 10/10/2015 04:20 PM, Eero Volotinen wrote:
>>> Does it work usin netdev option?
>>> Eero
>>> 10.10.2015 4.17 ip. "Imre Gergely" <gimre at narancs.net> kirjoitti:
>>>> Hi
>>>> I have an IBM blade with internal harddisks, in hardware RAID1. I've
>>>> installed a CentOS 6 64bit on it, everything works just fine.
>>>> After the installation, I've presented a vdisk to the blade from an
>>>> external SAN (an HP EVA4000), connected through FiberChannel. I've
>>>> partitioned the disk, formatted it and mounted it under /store, then
>>>> added it to fstab. Everything was fine, until I rebooted.
>>>> At boot I'm getting the following error for /store:
>>>> Mounting local filesystems:  mount: special device
>>>> UUID=2a587e95-4a6c-4336-bb8b-f0d066905bc5 does not exist
>>>> It just goes on to boot without mounting this filesystem. After it
>>>> boots, I can log in and give the command "mount -a", and it gets
>> mounted
>>>> without problems.
>>>> As far as I can tell, the reason for this is that CentOS doesn't
>> wait
>>>> for the external disk to get initialized fully and it just doesn't
>> find
>>>> it at boot time. I have other CentOS blades, installed and booting
>> from
>>>> the same SAN and they work without problems, but I noticed that they
>>>> wait a little bit longer at boot.
>>>> Am I missing some stuff from initrd? What can I do to make it wait
>> for
>>>> the block device a bit longer before it tries mounting it ?
> Does dmesg provide any useful information? If you remove (assuming they are there) rhgb and quiet and add debug to the kernel line at boot time does that give you any more info? How does the dmesg output compare to one that is able to mount the disk at boot without issue?

Yes, I tried that, and look at dmesg, but couldn't find anything
interesting. The only useful info is that the drive is not ready when it
tries to mount it, but it becomes ready a little bit later. The one that
is mounting the disk without issue is a bit different because it also
boots from the SAN so it really needs to have the external storage
available from the beginning. This one boots from internal disk and only
later wants to mount the external disk.

Imre Gergely
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