# ZFS (?) strangeness



## miks (Dec 12, 2010)

Without any process working 







gstat every minute or so is showing high busy % on disk 






.

Can someone explain this?

System: FreeBSD 8.1 amd64 with zfs patched to v15.
Disks: degraded zmirror with currently one active drive (Western Digital Caviar Black 1 TB)
RAM: 8GB


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## graudeejs (Dec 12, 2010)

show
`$ zpool status`


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## miks (Dec 12, 2010)

```
pool: zroot
 state: DEGRADED
status: One or more devices could not be opened.  Sufficient replicas exist for
	the pool to continue functioning in a degraded state.
action: Attach the missing device and online it using 'zpool online'.
   see: http://www.sun.com/msg/ZFS-8000-2Q
 scrub: none requested
config:

	NAME                      STATE     READ WRITE CKSUM
	zroot                     DEGRADED     0     0     0
	  mirror                  DEGRADED     0     0     0
	    gpt/disk1             ONLINE       0     0     0
	    11497708687413159188  UNAVAIL      0     0     0  was /dev/gpt/disk0
```


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## AndyUKG (Dec 14, 2010)

Is it simply that the disk has died or there is an issue with the controller or cable? Can you run "camcontrol identify ada1" and "gpart show ada1"? You could also test reading off the device to /dev/null via dd if you are careful (not to accidentally write data to the disk).

thanks Andy.


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## miks (Dec 14, 2010)

```
[root@xxxx /home/yyyy]# camcontrol identify ada1
pass1: <WDC WD1001FALS-00J7B0 05.00K05> ATA-8 SATA 2.x device
pass1: 300.000MB/s transfers (SATA 2.x, UDMA6, PIO 8192bytes)

protocol              ATA/ATAPI-8 SATA 2.x
device model          WDC WD1001FALS-00J7B0
firmware revision     05.00K05
serial number         WD-WMATV0730410
WWN                   50014ee01137cbc
cylinders             16383
heads                 16
sectors/track         63
sector size           logical 512, physical 512, offset 0
LBA supported         268435455 sectors
LBA48 supported       1953525168 sectors
PIO supported         PIO4
DMA supported         WDMA2 UDMA6 

Feature                      Support  Enable    Value           Vendor
read ahead                     yes	yes
write cache                    yes	yes
flush cache                    yes	yes
overlap                        no
Tagged Command Queuing (TCQ)   no	no
Native Command Queuing (NCQ)   yes		32 tags
SMART                          yes	yes
microcode download             yes	yes
security                       yes	no
power management               yes	yes
advanced power management      no	no	0/0x00
automatic acoustic management  yes	no	254/0xFE	128/0x80
media status notification      no	no
power-up in Standby            yes	no
write-read-verify              no	no	0/0x0
unload                         no	no
free-fall                      no	no
data set management (TRIM)     no
```

and


```
[root@xxxx /home/yyyy]# gpart show ada1
=>        34  1953525101  ada1  GPT  (932G)
          34         128     1  freebsd-boot  (64K)
         162     8388608     2  freebsd-swap  (4.0G)
     8388770  1945136365     3  freebsd-zfs  (928G)
```

does smartcl will show any info about errors if drive is dying?


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## AndyUKG (Dec 14, 2010)

miks said:
			
		

> does smartcl will show any info about errors if drive is dying?



Not personally used it, but seems so:

http://www.cyberciti.biz/tips/linux-find-out-if-harddisk-failing.html

Also you can test something like:


```
dd if=/dev/ada1p3 of=/dev/null count=1000000
```

That will presumably fail going by what you are seeing from iostat. Interesting that the other partions aren't showing 100% busy on the same disk. Further to that you could also try dd'ing from the swap or root partition on ada1.


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## chrcol (Dec 17, 2010)

patch it to STABLE, even tho its prerelease.

the zfsv15 patch has issues.  STABLE has it already merged.

although that may well have nothing to do with your current problem.


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