# graid3 and geom results



## bluetick (Jan 22, 2010)

I had a raid setup with graid3, after repeted power outage due to ice storm, one drive dropped out. The results from geom disk list of the 3 drives are as follows.

```
Geom name: ad10
Providers:
1. Name: ad10
   Mediasize: 500107862016 (466G)
   Sectorsize: 512
   Mode: r1w1e1
   fwsectors: 63
   fwheads: 16

Geom name: ad12
Providers:
1. Name: ad12
   Mediasize: 500107862016 (466G)
   Sectorsize: 512
   Mode: r1w1e1
   fwsectors: 63
   fwheads: 16

Geom name: ad14
Providers:
1. Name: ad14
   Mediasize: 500107862016 (466G)
   Sectorsize: 512
   Mode: r0w0e0  <<<<< result in question >>>>>
   fwsectors: 63
   fwheads: 16
```

I've searched for hints at the mode results but have not found a answer, is it out of write mode or dead??

from dmesg at reboot


```
GEOM_RAID3: Device raid3/t1 launched (3/3).
GEOM_RAID3: Component ad14 (device t2) broken, skipping.
GEOM_RAID3: Device raid3/t2 launched (2/3).
```

Can I run fschk on the drive ad14 without data loss on the other drives in the raid?? Or Is it just dead? =) 

I can ssh into the computer but it's an one hour drive to touch it.


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## mav@ (Jan 22, 2010)

Every drive of 3-disk RAID3 has only half of all information. It can't be used separately. Degraded RAID3 (2 of 3) same time still can be used, but may have reduced performance.


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## bluetick (Jan 22, 2010)

After reading this article http://phk.freebsd.dk/pubs/bsdcon-03.slides.geom-tutorial.pdf  Iâ€™ve started a zero write of the drive to clear out the geom info and data on the drive, in the hope that it was corrupt and will be able to rejoin the drive to the raid.


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