[OmniOS-discuss] dedup causes zfs/omnios to drop connections.

[John Yocum]

On 12/15/2014 12:43 PM, Rune Tipsmark wrote:
> hi all,
> 
>  
> 
> got a new system I was intending on using as backup repository. Whenever
> dedup is enabled it dies after anywhere between 5 and 30 minutes. I need
> to reboot OmniOS to get it back online.
> 
> the files being copied onto the zfs vols are rather large, about ~2TB
> each... if I copy smaller files, say 400GB or so, it takes longer for it
> to crash.
> 
>  
> 
> what can be done to fix this? after Windows (initiator) looses the
> connection (both Fibre Channel and iSCSI) I still see a lot of disk
> activity using iostat - disks remain active for minutes after the
> copying has died... its like ZFS cannot handle dedup of large files..
> 
> br,
> 
> Rune
> 

How much RAM do you have? And, how big is your ZFS pool? I ask, as dedup
requires a ton of RAM. Helpful reference on the issue
http://utcc.utoronto.ca/~cks/space/blog/solaris/ZFSDedupMemoryProblem

-- 
John Yocum, Systems Administrator, DEOHS