# Drive not appear in /dev

## mkp

Hi,

I have a problem with one new hdd attached to Gentoo box. It's connected to Adaptec 1220sa with another drive. Both are new and 2tb size but only one is visible. Both are shown in kernel logs, one is /dev/sdd, other is /dev/sde but when try fdisk /dev/sde i've got error "Unable to open /dev/sde". If i check /proc/partitions it's there.

```
test linux-3.6 # cat /proc/partitions

major minor  #blocks  name

   8        0  234431064 sda

   8        1     112640 sda1

   8        2   40163328 sda2

   8        3  194153472 sda3

   8       16 1953514584 sdb

   8       32 1953514584 sdc

   8       48 1953514584 sdd

   8       64 1953514584 sde

  11        0    1048575 sr0

   9        0 1953514496 md0
```

The drive is visible only in logs and if i run lshw:

```
*-disk UNCLAIMED

       description: ATA Disk

       product: WDC WD20EFRX-68E

       vendor: Western Digital

       physical id: 0.0.0

       bus info: scsi@5:0.0.0

       version: 82.0

       serial: WD-WCC4M2JL0FCJ

       configuration: ansiversion=5
```

Before that Adaptec, i tried asm1061 controler .. the result was the same. The problem is that i have only 4 sata ports on motherboard and 5 drives. Is there something in the kernel config which i miss? It's not possible to have limitation of connected drives.

How to find what is wrong?

Thanks.

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## NeddySeagoon

mkp,

That controller supports fakeraid and Just A Bunch Of Drives (JBOD) mode.

If its in fakeraid mode, the operating system will see both drives at a low level but only one (the raid set) at a higher level.

Make sure its in JBOD mode.

If that's not it, post your lspci output.

If you want another wild guess. the card implements a SATA Expander. That's like a hub to have more that one drive on a single SATA port.

That's not quite so horrible an it sounds, its only a single lane PCIe card so it can't keep both dives busy at the same time anyway.

SATA Expander is a kernel option.

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## mkp

Hi NeddySeagoon,

I set a fake raid1 through adaptec menu. I know it's normal to see only 1 drive but if it's a hardware raid. So, do i have same info on this 2 drives or not? Like is normal when have raid1.

Thanks.

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## szatox

mkp, don't mistake hardware-dependent software raid with actual hardware raid.

Fakeraid is the former, which means it collects all the disadvantages from both worlds. If you don't have a really good reason to use it, simply disable it and use plain softraid instead (mdraid, lvm, anything but fake raid).

 *Quote:*   

> So, do i have same info on this 2 drives or not? 

  We don't have any way to know for sure what option did you set. I suppose* it's a sort of capacity raid: either striped RAID0 or linear JBOD (next drive appended to previous one).

You can try getting some information from lsblk: what is the size of your fakeraid compared to physical drives inside?

* If you put 2 drives in, you obviously want to see the available space double. Making mirrors by default would result in shitloads of complains from unhappy SOHO users. I'm intentionally leaving any comments on usefulness of redundancy out, because it not the point here.

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## NeddySeagoon

mkp,

Its not hardware raid.

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## mkp

Hi,

It was so simple. Just execute MAKEDEV sdX and voila , drive appear. 

Thanks.

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