Re: ZFS L2ARC - incorrect size and abnormal system load on r255173

First off I just wanted to clarify that you don't need to compression on
dataset for L2ARC to use LZ4 compression, it does this by default as is
not currently configurable.

Next up I believe we've found the cause of this high load and I've just
committed the fix to head:
http://svnweb.freebsd.org/base?view=revision&sortby=file&revision=256889

Thanks to Vitalij for testing :)

Dmitriy if you could test on your side too that would be appreciated.

    Regards
    Steve

----- Original Message ----- 
From: "Vitalij Satanivskij" <satan_at_ukr.net>
To: "Allan Jude" <freebsd_at_allanjude.com>
Cc: <freebsd-current_at_freebsd.org>
Sent: Thursday, October 10, 2013 6:03 PM
Subject: Re: ZFS L2ARC - incorrect size and abnormal system load on r255173


> AJ> Some background on L2ARC compression for you:
> AJ> 
> AJ> http://wiki.illumos.org/display/illumos/L2ARC+Compression
> 
> I'm alredy see it.
> 
> 
> 
> AJ> http://svnweb.freebsd.org/base?view=revision&revision=251478
> AJ> 
> AJ> Are you sure that compression on pool/zfs is off? it would normally
> AJ> inherit from the parent, so double check with: zfs get compression pool/zfs
> 
> Yes, compression turned off on pool/zfs, it's was may time rechecked.
> 
> 
> 
> AJ> Is the data on pool/zfs related to the data on the root pool? if
> AJ> pool/zfs were a clone, and the data is actually used in both places, the
> AJ> newer 'single copy ARC' feature may come in to play:
> AJ> https://www.illumos.org/issues/3145
> 
> No, both pool and pool/zfs have diferent type of data, pool/zfs was created as new empty zfs (zfs create pool/zfs)
> 
> and data was writed to it from another server. 
> 
> 
> Right now one machine work fine with l2arc. This machine without patch for corecting ashift on cache devices.
> 
> At last 3 day's working with zero errors. Another servers with same config similar data, load and so on after 2 day 
> work began report abouy errors.
> 
> 
> AJ> 
> AJ> 
> AJ> 
> AJ> -- 
> AJ> Allan Jude
> AJ> 
> AJ> _______________________________________________
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