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From: Duncan <1i5t5.duncan@cox.net>
To: linux-btrfs@vger.kernel.org
Subject: Re: RAID10 Balancing Request for Comments and Advices
Date: Thu, 18 Jun 2015 04:37:54 +0000 (UTC)	[thread overview]
Message-ID: <pan$36ab7$1065ac1$398f382$7ec3408d@cox.net> (raw)
In-Reply-To: 20150617132736.GT9850@carfax.org.uk

Hugo Mills posted on Wed, 17 Jun 2015 13:27:36 +0000 as excerpted:

>> Yes, on this 80% full 6x4TB RAID10 -dusage=15 took 2 seconds and
>> relocated "0 out of 3026 chunks”.
>> 
>> Out of curiosity, I had to use -dusage=90 to have it relocate only 1
>> chunk and it took les than 30 seconds.
>> 
>> So I put a -dusage=25 in the weekly cron just before the scrub.
> 
> In most cases, all you need to do is clean up one data chunk to
> give the metadata enough space to work in. Instead of manually iterating
> through several values of usage= until you get a useful response, you
> can use limit=<n> to stop after <n> successful block group relocations.

Thanks, Hugo.  It wasn't previously clear to me what the practical usage 
for the (relatively new) limit= filter was.  Very useful explanation. =:^)

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman


  parent reply	other threads:[~2015-06-18  4:38 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-16 12:09 RAID10 Balancing Request for Comments and Advices Vincent Olivier
2015-06-16 12:25 ` Hugo Mills
2015-06-16 13:34   ` Vincent Olivier
2015-06-16 23:58     ` Duncan
2015-06-17  0:14       ` Chris Murphy
2015-06-17 13:13         ` Vincent Olivier
2015-06-17 13:27           ` Hugo Mills
2015-06-17 13:29             ` Vincent Olivier
2015-06-18  4:37             ` Duncan [this message]
2015-06-17 13:46       ` Vincent Olivier
2015-06-18  8:00         ` Duncan

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