Poor man's RAID1 between an SSD and a hard driveFeeding the Cloud
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https://feeding.cloud.geek.nz/posts/poor-mans-raid1-between-ssd-and-hard-drive/Feeding the Cloudikiwiki2019-09-02T18:28:41Zwhy all the --exclude's?https://feeding.cloud.geek.nz/posts/poor-mans-raid1-between-ssd-and-hard-drive/comment_1_57ee2f860f1a077507bee62bacc292c2/Timo Juhani Lindfors2013-04-01T17:14:48Z2013-04-01T08:26:09Z
<p>Hmm, why do you need all of those "--exclude" options? Shouldn't "-x" be enough to ensure that e.g. /sys is not copied?</p>
<p>Also, is there some particular reason why you are not using "--numeric-ids"?</p>
Re: why all the --exclude's?https://feeding.cloud.geek.nz/posts/poor-mans-raid1-between-ssd-and-hard-drive/comment_2_54f90aba90da596cbe64df934465139e/fmarier2013-04-01T17:18:31Z2013-04-01T17:18:16Z
<p>Regarding the excludes, I think you're right, I might be able to remove most of them given that they would cross filesystem boundaries anyways.</p>
<p>As for the numeric-ids option, I've looked at the manpage, but I honestly don't understand how that would make a difference in this case. Do you think it would help with anything?</p>
Why don't you use a real raid1?https://feeding.cloud.geek.nz/posts/poor-mans-raid1-between-ssd-and-hard-drive/comment_3_f2deed14cb710282fbbadb8a9ec13c57/Andre2013-04-01T22:59:12Z2013-04-01T22:22:16Z
Is there any specific reason to not use a real raid1 with mdadm for mirroring? It would work as well as your current setup, and provide the same benefits without using a second encryption.
Re: Why don't you use a real raid1?https://feeding.cloud.geek.nz/posts/poor-mans-raid1-between-ssd-and-hard-drive/comment_4_d2e525e8ef810d579db9e721362bf734/fmarier2013-04-09T23:38:01Z2013-04-01T23:01:04Z
<p>I didn't try a real RAID1 setup, but I suspect that I might lose some of the performance advantages of having an SSD if I/O is blocked on the rotating drive.</p>
<p>Also, from a power usage point of view, it would mean that the hard drive needs to be spinning all the time, as opposed to every couple of hours.</p>
Your title said RAID1...https://feeding.cloud.geek.nz/posts/poor-mans-raid1-between-ssd-and-hard-drive/comment_5_8e548908487f2d40ea9285800441daf1/Alexis Wilke2019-09-02T18:28:41Z2019-09-01T23:03:01Z
<p>I totally agree that a RAID1 would kill the speed of SSD. But then, your post title says RAID1... <img alt=":-)" src="https://feeding.cloud.geek.nz/smileys/smile.png" /></p>
<p>Now, I wanted to mention that if you know the name of your device, you can check whether it's a rotational (HDD) or not (SSD). Here is an example of how you get the flag:</p>
<p>alexis~$ cat /sys/block/sda/queue/rotational</p>
<p>The file is either a 0 (SSD) or a 1 (HDD). What you need is the "sda" part of the path. In a shell script, it can be difficult to grab that info. Although a function such as "df ." give you the info, it's not that practical.</p>
<p>Anyway, your solution is pretty much what I had in mind. Thank you.</p>