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I have configured my hard drives to go to sleep after 1 minute of inactivity. This used to work very well; the server was almost always dead silent. But recently the drives are more often awake.
Can I check what is keeping them from going to sleep? This is a home server.
rc.local:
hdparm -M 128 -S 60 /dev/sda
hdparm -S 60 /dev/sdb
Update: The server is running Ubuntu 10.04. The OS, with /tmp and /var/, is on an SSD, while sda and sdb are only used for storage/backup.
Update 2: From my sysctl.conf:
vm.swappiness = 1
vm.vfs_cache_pressure = 50
vm.dirty_writeback_centisecs = 1500
vm.dirty_ratio = 20
vm.dirty_backgrounds_ratio = 10
1Are you aware that by spinning down the drives you're shortening their already short lives? – None – 2010-10-09T11:27:48.393
@John: do you have a solid reference for that? I've seen it argued both ways. @Znarkus: I guess you're running Linux, from your use of
hdparm
, but you should state your OS explicitly in your question. – Gilles 'SO- stop being evil' – 2010-10-09T12:13:20.997Most disk wear is from the heat-up/cool-down cycle. The less you do that, the longer it will last. – Chris S – 2010-10-09T15:30:11.667
@Gilles, I don't know of a reference you can look up but personal experience of nearly 4 decades, as well as an understanding of why the wear takes place, is kind of hard to ignore. – None – 2010-10-09T21:34:25.373
@John: I've learnt to be wary of this kind of “conventional wisdom” — the same that claims that hard drives should run as cool as possible (which turned out to be false). I've asked for quantitative data in a separate question.
– Gilles 'SO- stop being evil' – 2010-10-10T12:16:08.953That is very interesting. But as non solid state disks make so much noise and produces heat from their relative high energy consumption, I can't have them spinning all day. I've updated the question with more information – Znarkus – 2010-10-12T10:56:42.167