Understanding LVM2 behavior in case of disk failure?

Understanding LVM2 behavior in case of disk failure?

I have a LVM2 group using the following command for a 5x4TB set up: pvcreate devsdb,c,d,e,f vgcreate vg0 devsdb,c,d,e,f lvcreate -l 100FREE -n lvol1 vg0 Now that I created this monster, I have some question about it: in the default configuration which happens to be linear, what happens if devsdb fails Should I say good bye to the whole devsdb data or LVM is placing the files on the whole device rather than trying to fill in the first bytes How can I tell which file is on which device If I am to lost a disk, Id like to know where the data is lost in order to be able to restore it if possible.

Комментарии

Отправить комментарий

Популярные сообщения из этого блога

FillChar and StringOfChar under Delphi 10.2 for Win64 Release Target

FillChar and StringOfChar under Delphi 10.2 for Win64 Release Target I have a question about a specific programming problem in Delphi 10.2 Pascal programming language. The StringOfChar and FillChar dont work properly under Win64 Release build on CPUs released before year 2012. Expected result of FillChar is just plain sequence of just repeating 8-bit characters in a given memory buffer. Expected result of StringOfChar is the same, but the result is stored inside a string type. But, in fact, when I compile our applications that worked in Delphi prior to 10.2 by the 10.2 version of Delphi, our applications compiled for Win64 stop working properly on CPUs released before year 2012. The StringOfChar and FillChar dont work properly they return a string of different characters, although in a repeating pattern not just a sequence of the same character as they should. Here is the minimal code enough to demonstrate the issue. Please note that the length of the sequence should be at least ...
Далее...

Intuition behind successive squaring.

Intuition behind successive squaring. I was looking at the successive squaring method used commonly in modular exponentiation problems and was wondering why we are able to square the remainder of successive powers of a number. For example for 7327 mod 853: 71 equiv mod 853 72 equiv 49 mod 853 49 74 equiv 492 mod 853 695 78 equiv 6952 mod 853 227 ... 7256 equiv 6282 mod 853 298 During this operation, why is that we square the remainder and how do we know that doing so will relate to the final answer Im struggling to understand the intuition behind this strategy and why this actually works. You are trying to arrive at the answer with as little computation as possible. You could have arrived to the answer by multiplying 7 mod853 to itself 327 times. But that will take forever. Now, note that any integer 327 for example can be expressed in binary. For example, 327 101000111_2. This means that 327 1 2 4 64 256. If you somehow had the values of 71, 72, 74, 764, 7256 mod 8...
Далее...