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Can cp/mv commands cause high load?
Hello guys,
Can you please tell me if this is normal? I copied a 2gb backup file from one directory to another and it caused high load to the server.
First attempt is using mv. 1-minute high load reaching up to ~30; cpu wait reaching up to ~40
Second attempt using cp. 1-minute high load reaching up to ~12; cpu wait reaching up to ~45
KVM server on a leased dedi, E3-1230 cpu, 2x1TB HDD sw-raid1
Thanks.
Comments
That's what I did.
mv gets 40-65 CPU usage with top while cp is much lower max of 0.3-1.
nope, same. just moving file to another directory.
If it's within the same filesystem, mv shouldn't cause any kind of load, since the data isn't being read or written. The only thing being written is an update to one single inode.
No unless the HDD is overloaded with VPS accounts. Simply ask your provider to move to other node, as current is overloaded!
Only 1 KVM VPS on the server. Do you think this is a faulty HDD?
Failed hard drive would be my guess if a mv within the same filesystem is causing any load, yes.
Is your mdadm out of sync?
I see I see.
@AnthonySmith I am not actually sure. I only have access to the KVM not to the node itself. I will consult my provider.
By the way, I repeated the mv a while ago. 3rd attempt = 1-minute high load reached ~70, cpu wait now ~99.
Smartctl -a /dev/sdX
Look for reallocated or pending sector counts. Smart errors are also bad.
Ahh didnt see u dont have access to host.. Have provider smarttest the host drives
thanks, i will tell them that.
A 2gb file should not cause heavy load. If the IO is already being hit pretty hard, it can. It may not even appear to the provider that the IO is being hit very hard. I've run into some issues recently that have tested me a bit on this issue, but we're talking moving a couple hundred GB around, not just 2GB. I'd explain further but I'm still scratching my head about it.
by any chance are you using IDE in the KVM virtual server?
@qjq you got that right.
the fix was to change from ide to virtio and choosing deadline scheduler for centos.