Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 17 Jan 2013 20:18:14 +0100
From:      "Ronald Klop" <ronald-freebsd8@klop.yi.org>
To:        freebsd-fs@freebsd.org
Subject:   Re: slowdown of zfs (tx->tx)
Message-ID:  <op.wq2k8or38527sy@212-182-167-131.ip.telfort.nl>
In-Reply-To: <20130117093259.GA83951@mid.pc5.i.0x5.de>
References:  <20130114195148.GA20540@mid.pc5.i.0x5.de> <CAFqOu6jwJ4qhbOovN_NhzusdQJvrbvUC3g93sziR=Uw99SGenw@mail.gmail.com> <20130114214652.GA76779@mid.pc5.i.0x5.de> <CAFqOu6jKX-Ks6C1RK5GwZ51ZVUSnGSe7S99_EfK%2BfwLPjAFFYw@mail.gmail.com> <20130115224556.GA41774@mid.pc5.i.0x5.de> <CAFqOu6jJnWdbikPmE1-UML5i_x7meF%2BiyY=9WBRyv2j7AeOaSg@mail.gmail.com> <50F67551.5020704@FreeBSD.org> <20130116095009.GA36867@mid.pc5.i.0x5.de> <FD780217EA4548F187715AF1AAF2B91A@multiplay.co.uk> <50F69788.2040506@FreeBSD.org> <20130117093259.GA83951@mid.pc5.i.0x5.de>

next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, 17 Jan 2013 10:32:59 +0100, Nicolas Rachinsky  
<fbsd-mas-0@ml.turing-complete.org> wrote:

> * Andriy Gapon <avg@FreeBSD.org> [2013-01-16 14:05 +0200]:
>> on 16/01/2013 12:14 Steven Hartland said the following:
>> > You only have ~11% free so yer it is pretty full ;-)
>>
>> just in case, Steve is not kidding.
>>
>> Those free hundreds of gigabytes could be spread over the terabytes and  
>> could be
>> quite fragmented if the pool has a history of adding and removing lots  
>> of files.
>>  ZFS could be spending quite a lot of time in that case when it looks  
>> for some
>> free space and tries to minimize further fragmentation.
>>
>> Empirical/anecdotal safe limit on pool utilization is said to be about  
>> 70-80%.
>>
>> You can test if this guess is true by doing the following:
>> kgdb -w
>> (kgdb) set metaslab_min_alloc_size=4096
>>
>> If performance noticeably improves after that, then this is your  
>> problem indeed.
>
> I tried this, but I didn't notice any difference in performance.
>
> Next I'll try the update Artem suggested.
>
> Thanks
>
> Nicolas

Did you already try to free some space?

Ronald.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?op.wq2k8or38527sy>