[linux-lvm] Server hangs when writing to LVM volume due to LVM Snapshots

[Tomasz Chmielewski]

Veselin Kantsev schrieb:
> Hello Tomasz,
> thank you much for the prompt reply.
> 
> The server has 6119216k of RAM in total.

That's quite a bit..
You would need terabytes of snapshots to fill it.
So perhaps it hangs for a different reason.

Capacitors? Hardware?


> And most of it is shown as used all the time (To my knowledge thats just how
> linux utilizes ram). 

Please show the output of "free" command. The "buffers/cache" line is 
your current RAM usage, excluding buffers (more or less).


> But from memory, the last time the server froze during copying (goes
> back to normal once I kill the copy process) I didn't notice any extreme
> RAM usage or swapping.

Kernel data in memory used for snapshots will not be swapped out.


> As I'm rotating LVM snapshots weekly, there are 7 snapshots on the system
> at all times, and 1 of them is active(the last one taken).

(...)

> Do you see a flaw in this process that might be causing the issues?

Unless you have terabytes of data in snapshots, it shouldn't be a problem.

Does it freeze for good? Machine stops responding, stops logging, etc.?


-- 
Tomasz Chmielewski
http://wpkg.org