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From: Duncan <1i5t5.duncan@cox.net>
To: linux-btrfs@vger.kernel.org
Subject: Re: snapshot space available
Date: Tue, 27 Aug 2013 06:29:30 +0000 (UTC)	[thread overview]
Message-ID: <pan$add47$4ad22f14$35690eac$3b7c510f@cox.net> (raw)
In-Reply-To:  6FCC5036-CC36-4DA3-8594-1FA23F3BB256@colorremedies.com

Chris Murphy posted on Mon, 26 Aug 2013 09:15:46 -0600 as excerpted:

> I'm uncertain if autodefrag avoids this problem. It does seem like in
> certain instances, like this, the file system needs to be able to prune
> itself somehow, like a partial balance to consolidate data chunks and
> then release their space so they can become metadata chunks.

Intriguing question re defrag.  I hadn't thought of the possibility until 
you suggested it, but indeed, tracking hundreds of extents instead of one 
or a dozen, does sound like it could reduce metadata usage, reducing the 
chance of running into the issue in the first place as well as lessening 
the chance of a "simple" delete temporarily requiring significant new 
metadata resources in ordered to track all those extent frees before the 
final atomic root entry update.

-- 
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:[~2013-08-27  6:29 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-26 13:35 snapshot space available Russell Coker
2013-08-26 14:47 ` Clemens Eisserer
2013-08-26 15:27   ` Chris Murphy
2013-08-26 19:09     ` Chris Murphy
2013-08-31  9:04       ` Russell Coker
2013-08-31 17:27         ` Chris Murphy
2013-08-26 15:15 ` Chris Murphy
     [not found] ` < 6FCC5036-CC36-4DA3-8594-1FA23F3BB256@colorremedies.com>
2013-08-27  6:29   ` Duncan [this message]

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