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Subject: Re: [RFC] Thing 1: Shardmap fox Ext4
From:   Daniel Phillips <daniel@phunq.net>
To:     Andreas Dilger <adilger@dilger.ca>
Cc:     "Theodore Y. Ts'o" <tytso@mit.edu>, linux-ext4@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
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Message-ID: <57e71e35-b3a4-67e8-d5db-af3b41e9230a@phunq.net>
Date:   Wed, 4 Dec 2019 12:53:28 -0800
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On 2019-12-04 12:47 p.m., Daniel Phillips wrote:
> On 2019-12-04 10:03 a.m., Andreas Dilger wrote:
>>> Here is a pretty picture to get started:
>>>
>>>     https://github.com/danielbot/Shardmap/wiki/Shardmap-media-format
>>
>> The shardmap diagram is good conceptually, but it would be useful
>> to add a legend on the empty side of the diagram that shows the on-disk
>> structures.
> 
> Sounds good, but not sure exactly what you had in mind. Fields of a
> shard entry? Fields of the block 0 header? The record entry block has
> its own diagram, and is polymorphic anyway, so no fixed format.

Ah, the legend can explain that lower tier shard 2 is in process of
being split into upper tier shards 4 and 5, and label the shards
with offset numbers.