# [SOLVED] Very big device. - Areca RAID controller

## Zee

Hi all.

  I upgraded my RAID-5 array from 8x 320 GB hard drives to 8x 1000 GB. At the same time I moved the / filesystem to small SSD drive. The system boots fine & fast but dmesg says this (about the RAID array):

sd 0:0:0:0: [sda] Very big device. Trying to use READ CAPACITY(16).

sd 0:0:0:0: [sda] 9765624320 512-byte hardware sectors (5000000 MB)

sd 0:0:0:0: [sda] Write Protect is off

sd 0:0:0:0: [sda] Mode Sense: cb 00 00 08

sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA

sd 0:0:0:0: [sda] Very big device. Trying to use READ CAPACITY(16).

sd 0:0:0:0: [sda] 9765624320 512-byte hardware sectors (5000000 MB)

sd 0:0:0:0: [sda] Write Protect is off

sd 0:0:0:0: [sda] Mode Sense: cb 00 00 08

sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA

 sda: unknown partition table

sd 0:0:0:0: [sda] Attached SCSI disk

 I am using kernel 2.6.24-gentoo-r4. The RAID controller is an ARECA ARC-1230.

 Is this a kernel-related issue or a controller-related one?

thanks in advance,

zeeLast edited by Zee on Sun Jan 11, 2009 12:53 am; edited 1 time in total

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## danomac

That's normal. It's saying it's a large volume and it's going to have to use large block device support.

If you have a x86 kernel, make sure CONFIG_LBD is built into the kernel (it's under "Enable the block layer".)

I have a highpoint controller with a large raid5 as well.

 *Quote:*   

>  sda: unknown partition table

 

Keep in mind you can't use MBR partition tables to use this drive (MBR is limited to 2TB partitions.) You'll have to build EFI GUID Partition support in the kernel, and use parted to create a GPT table, partition it, then format it.

I also noticed that Windows and Linux use the same data partition identifier for GPT tables, so Vista will want to reformat the partition if you accidentally click on it.

Another option is to format the entire drive (use mke2fs on /dev/hpt, instead of /dev/hpt1) then Windows will hide it and leave it alone.

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## Zee

Hi.

  I can't find the option you're describing:

--- Enable the block layer

[  ]   Support for tracing block io actions

[*]   Block layer SG support v4 (EXPERIMENTAL)

[  ]   Block layer data integrity support

(this snippet is from kernel 2.6.27)

 I did however find EFI GUID Partition support.

 Any tip?

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## danomac

What's the output of `uname -r`? 

If you are running a 64-bit kernel, I don't believe it's there. IIRC it's for 32-bit kernels only.

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## Zee

It is and will be a 64-bit kernel.

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## danomac

You won't need CONFIG_LBD then.

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## Zee

Excellent. I'm emerging parted ATM.   :Cool: 

Thanks for the help and explanations.

zee

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