Keeping disks busy [LWN.net]

Keeping disks busy

Posted Sep 27, 2002 16:46 UTC (Fri) by aglet (guest, #1334)
Parent article: Keeping disks busy

Probably the most inappropriate place for this comment, but I have the opposite problem. I'd like my disks to be kept as idle as possible.

A journalled filesystem is a very good thing for laptops, where power outages (and associated unclean shutdowns) are a relatively frequent ocurrence. I've switched my laptop over to ext3 for unrelated reasons (IRQ problems cause it to lock up every now and then, necessitating a hard reset, and the disk is big enough for this to be annoying...). I used to run noflushd so that the disk stayed spun down, but since ext3 does a flush every 5 seconds this has stopped working.

Which brings me, finally, to my question: is there any way to reconcile usage of a journalled filesystem with civilised battery usage? I'm aware of course that if changes were only committed to disk rarely I'd risk losing more data, but I'd like to be able to make that trade-off.

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Keeping disks busy

Posted Sep 27, 2002 18:47 UTC (Fri) by steveha (guest, #3876) [Link]

Have you looked into "noatime"? By default, the disk system keeps track of when you access files -- reading a file is accessing it, so reading a file results in a write to update the access time. If you add the "noatime" option to your /etc/fstab file (where the filesystem mounting options are specified) it will cut down your disk writes.

steveha

Keeping disks busy

Posted Sep 28, 2002 15:09 UTC (Sat) by chaostrophy (guest, #662) [Link]

Have a look at the last few kernel traffics (http://kt.zork.net/kernel-traffic/). There were some patches to help with that, it delays writes until some read must happen, then spins the disk up, flushs all writes, and does as much reading as it can.

Here is is from lwn:
http://lwn.net/Articles/1652/

OK, so it was more than 2-3 weeks ago.

Good luck,
Ron

looking for a sysadmin gig