blocks|key|933659|text|根据描述：Bscp通过SSH连接复制单个文件或块设备，只传输已更改的部分。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|entityMap|0|LINK|mutability|MUTABLE|url|https://bscp-tool.github.io/^0|5|4|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@$A|L|B|M|1|N]]|C|$]]]|D|$E|$5|F|G|H|C|$I|J]]]]

According to the description: <a href="https://bscp-tool.github.io/" rel="nofollow noreferrer">Bscp</a> copies a single file or block device over an SSH connection, transferring only the parts that have changed.

blocks|key|3533604|text|现在，rsync支持复制设备，包括：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3533605|rsync+--copy-devices+--write-devices+<FROM>+<TO>|code-block|syntax|javascript|3533606|注意，只有在找到实际的设备节点时，它才会写入设备。所以不要使用/dev/mapper/<VG>-<LV>作为目标，因为它只会(尝试)用包含源设备内容的文件替换符号链接。|3533607|其中之一--*link*选项可能会告诉它遵循这些符号链接，但我只是使用/dev/dm-而不是。|entityMap^0|3|5|0|0|V|L|0|4|8|Z|8^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|S|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|T|8|@$9|U|A|V|B|C]]|D|@]|E|$]]|$1|M|3|N|5|6|7|W|8|@$9|X|A|Y|B|C]|$9|Z|A|10|B|C]]|D|@]|E|$]]]|O|$]]

Nowadays, <code>rsync</code> supports copying devices, with:
<pre><code>rsync --copy-devices --write-devices &lt;FROM&gt; &lt;TO&gt;
</code></pre>
Beware that it only writes to a device if it finds an actual device node. So don't use <code>/dev/mapper/&lt;VG&gt;-&lt;LV&gt;</code> as the destination since it will just (try to) replace the symlink with a file containing the content of the source device.
[ One of its <code>--*link*</code> options can probably tell it to follow those symlinks, but I just use <code>/dev/dm-&lt;NN&gt;</code> instead. ]

blocks|key|933711|text|遗憾的是，目前的答案似乎是“否”：我还没有找到任何将rsync方法引入块设备镜像的工具。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|933712|我对此感到惊讶，因为我期望有足够的需求这样一个工具，以维护定期更新的克隆大容量，低变化驱动器有效。这不像写速度(特别是对于外部硬盘驱动器)已经达到这样的速度，使它没有意义。|933713|你的拇指驱动器在现代意义上其实是相当小的:想象一下你想保留1TB笔记本电脑HDD的“热备用”(今天并不少见)。克隆整个驱动器(到另一个硬盘上)甚至要花费几个小时的USB3时间，而当可能只有几个GB实际上被更改时，不必要的写入量简直是疯了。|933714|顺序校验和-比较驱动器将大大节省时间和磨损在这种情况下。更好的是一个有状态的工具，它保留了上次运行时的校验和:它假设目标驱动器自那以后没有变化，所以只需要对源驱动器进行校验。|933715|要是有这样的工具就好了！|entityMap^0|Q|5|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|R|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|S|8|@]|D|@]|E|$]]|$1|J|3|K|5|6|7|T|8|@]|D|@]|E|$]]|$1|L|3|M|5|6|7|U|8|@]|D|@]|E|$]]]|N|$]]

With regret, it seems the answer at present is &quot;No&quot;: I have not found any tool that brings the <code>rsync</code> approach to block-device mirroring.
I'm surprised at this, as I'd expect there to be sufficient demand for such a tool, for maintaining regularly-updated clones of large-capacity, low-change drives efficiently. It's not like write speeds (especially for external hard drives) have reached such speeds as to make it moot yet.
Your thumbdrives are actually quite small in modern terms: imagine you wanted to keep a &quot;hot spare&quot; of a 1TB laptop HDD (not uncommon today). Cloning the whole drive (to another HDD) would take several hours even over USB3, and the amount of gratuitous writing when only perhaps a couple of GB are actually changed, is just crazy.
Sequentially checksum-comparing the drives would save hugely on time and wear in these circumstances. Even better would be a stateful tool, that retained the checksums from the last run: it would assume that the destination drive is unchanged since then, so would only need to checksum the source drive.
If only such a tool existed!

blocks|key|3533497|text|blocksync提供了bscp和更多的所有选项。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3533498|当地圣人：|3533499|#+python+blocksync.py+/dev/source/file+localhost+/path/to/destination/file|code-block|syntax|javascript|3533500|网络使用：|3533501|#+python+blocksync.py+/dev/source/file+user@destination.example.com+/path/to/destination/file`|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/theraser/blocksync|1|https://github.com/theraser/blocksync/blob/master/blocksync.py#L348^0|0|9|C|4|0|9|0|H|2|1|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@$9|10|A|11|B|C]|$9|12|A|13|B|C]]|D|@$9|14|A|15|1|16]|$9|17|A|18|1|19]]|E|$]]|$1|F|3|G|5|6|7|1A|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|1B|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1C|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|1D|8|@]|D|@]|E|$K|L]]]|Q|$R|$5|S|T|U|E|$V|W]]|X|$5|S|T|U|E|$V|Y]]]]

<a href="https://github.com/theraser/blocksync" rel="nofollow noreferrer"><code>blocksync</code></a> provides all the options of <code>bscp</code> and <a href="https://github.com/theraser/blocksync/blob/master/blocksync.py#L348" rel="nofollow noreferrer">many more</a>.
Local sage:
<pre><code># python blocksync.py /dev/source/file localhost /path/to/destination/file
</code></pre>
Network usage:
<pre><code># python blocksync.py /dev/source/file user@destination.example.com /path/to/destination/file`
</code></pre>

blocks|key|933799|text|出于好奇，如果rsync+/dev/sdb到/dev/sdc会发生什么？您可能希望使用这样的虚拟磁盘来解决这个问题：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|933800|sudo+qemu-img+create+-f+raw+disk1.raw+40G
sudo+qemu-img+create+-f+raw+disk2.raw+40G|code-block|syntax|javascript|933801|安装磁盘，并复制和检查它们是否同步。|933802|sudo+modprobe+nbd+
sudo+qemu-img+--connect=/dev/nbd0+disk1.raw+--cache=unsafe+--discard=unmap
sudo+qemu-img+--connect=/dev/nbd0+disk2.raw+--cache=unsafe+--discard=unmap

sudo+gparted+|933803|创建ext4分区到第一个磁盘并复制东西..。|933804|链接/dev/nbd1+1到一个文件夹，因为nbd0尝试rsync+/dev/nbd1+0到linkedFolder/|933805|别忘了这只是一个想法。|933806|但更有效的解决办法是：|933807|简单的方法是使用虚拟磁盘离线同步他们回到网上..。|933808|您可以在实际或虚拟的eth适配器上使用ISCSI+ISER+NBD。|933809|wnbd-client.exe是在ceph中建立的。|933810|ISER需要CNA网卡(便宜的英特尔10+are无处不在)。|933811|ISCSI需要许多连接才能正常工作，有一些解决方案和缓存策略可以完美地工作，但细节不在这里。|entityMap^0|0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|13|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|14|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|15|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|16|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|17|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|18|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|19|8|@]|9|@]|A|$]]|$1|Q|3|R|5|6|7|1A|8|@]|9|@]|A|$]]|$1|S|3|T|5|6|7|1B|8|@]|9|@]|A|$]]|$1|U|3|V|5|6|7|1C|8|@]|9|@]|A|$]]|$1|W|3|X|5|6|7|1D|8|@]|9|@]|A|$]]|$1|Y|3|Z|5|6|7|1E|8|@]|9|@]|A|$]]|$1|10|3|11|5|6|7|1F|8|@]|9|@]|A|$]]]|12|$]]

Just out of curiosity, What happens if you rsync /dev/sdb to /dev/sdc ?
You might want to it out with virtual disks like this:
<pre><code>sudo qemu-img create -f raw disk1.raw 40G
sudo qemu-img create -f raw disk2.raw 40G
</code></pre>
to mount disks and copy and check if they synced
<pre><code>sudo modprobe nbd 
sudo qemu-img --connect=/dev/nbd0 disk1.raw --cache=unsafe --discard=unmap
sudo qemu-img --connect=/dev/nbd0 disk2.raw --cache=unsafe --discard=unmap

sudo gparted 
</code></pre>
create ext4 partition to first disk and copy things ...
link /dev/nbd1 to a folder as nbd0 try to rsync /dev/nbd0 to linkedFolder/
Do not forget that it is just an idea.
Bu more valid solution to your answer is :
Easy way is to use virtual disks take them offline sync them take them back online ...
You can use on real or virtual eth adapters with ISCSI ISER NBD.
wnbd-client.exe is established in ceph.
ISER requires CNA network card (cheap Intel 10Gbe's are all around).
ISCSI requires many connections to work properly , there are workarounds and cache strategies which works flawlessly but details are out of scope here ...

blocks|key|3533297|text|不，不可能。Rsync使用文件时间戳来确定要复制什么和跳过什么。在较低的级别上没有比文件更相似的东西。磁盘上的数据不记得曾经有不同的分区安排。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3533298|为了确保两个磁盘是相同的，在文件系统下工作的工具必须读取两侧的每个块，如果它们不同，则将源块复制到目标块上。这通常比无条件复制要慢。如果对目标磁盘的写入比读取慢得多(但与完全跳过未修改的文件所获得的rsync收益相比)，它可能会更快；我想我已经看到了一个这样做的工具，但现在找不到了。|3533299|如果您在一边对分区设置进行了更改，则在另一侧进行相同的更改，然后在各个文件系统上调用rsync。|offset|length|style|CODE|entityMap^0|0|0|16|5^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|M|8|@$F|N|G|O|H|I]]|9|@]|A|$]]]|J|$]]

No, and there can't be. Rsync uses file timestamps to determine what to copy and what to skip. There's nothing similar at a lower level than files. The data on the disk doesn't remember that there used to be a different partition arrangement.

In order to make sure that two disks are identical, a tool working underneath the filesystem would have to read every block on both sides and copy the source block onto the target block if they differ. That's usually slower than unconditionally doing the copy. It might be faster if writes to the target disk are a lot slower than reads (but still a far cry from what rsync gains by completely skipping unchanged files); I think I've seen a tool that did this but I can't find it now.

If you made a change to the partition setup on one side, make the same change on the other side, then call <code>rsync</code> on the individual filesystems.

I cloned several 32Gb pendrives with a linux system installed using dd. Later I did shrink a partition and I did some little more changes (in the "Master"). Is there any tool for transferring only the blocks changed for evoiding the slow full re-cloning with dd?

I thought in <code>rsync</code>, but it only seems to work with files.

Is there anything similar to rsync to syncing block devices?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我用dd安装了一个linux系统，克隆了几个32 dd的吊灯。后来，我缩小了一个分区，并做了一些更多的更改(在“主”中)。是否有任何工具仅用于转移更改的块，以唤起用dd进行缓慢的完全克隆？我认为在rsync中，它似乎只适用于文件。

问是否有类似于同步块设备的rsync？
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问是否有类似于同步块设备的rsync？
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