Hi On Mon, Feb 17, 2014 at 01:09:35PM +0000, Nuno Magalhães wrote: > Greetings, > > One of my 4 SATA HDDs is constantly making "write noise", as if it was > under heavy load. However, the system is idle (and recently > installed). > I can't see any activity on iotop and this starts immediately when i > turn on the box. The HDD activiy LED doesn't blink on this activity. > > All drives seem functional, smartctl -t short <device> only shows > errors for sdd, the oldest drive, but by the noise it makes when > running said test that's not the culprit and it doesn't even have > filesystems yet (it's one big LVM VG with no LVs). That leaves me with > 2 new drives (sda and sdc) that are part of a RAID1 array where / is > an xfs in an LV; and sdb which has /boot (256MB ext2) and /stuff (50GB > ext4 which is 1% full, also in an LV). > > I believe sdb may be the culprit. Also booting has become slow (from > about 3sec to over 10, stopping on loading linux, loading ramdisk, > mounting filesystems, etc). (Also GRUB delays on "error: unknown lvm > metadata header" for /dev/sdb1, but that's because /boot is not on LVM > - i've edited all 4 simlinks to it from /etc/lvm/lvm.conf but it still > looks at it; GRUB proceeds normally after that). > > Short of unplugging the drives one by one, is there a way i can a) > discover/confirm which one is thrashing about? and b) make it stop? > I've seen hdparm -s is not recommended, and i'm not sure if whichever > drive it is it supports the required power management feature (they > all support "Power Management feature set", but other power-related > features vary).
You may be able to get clues from sysstat - it can tell you how many blocks have been transferred to each device. However, it is not very granular in the default configuration: I believe it is every 10 minutes by default. But if you make the box idle for 30 minutes, and you still see IO to a drive, then that would be a good clue. Note that even read activity may cause writes - if the atime mount option is set (not sure whether this applies for XFS though). Thus reads from cache may still result in writes. Another possibility is cron jobs - but e.g. stopping cron for a period could be a useful diagnostic: if it still happens even with cron stopped, then cron is unlikely to be the culprit. Or at least: unlikely to be the *only* culprit. Same goes for logging - e.g. (r)syslogd activity. Hope this helps -- Karl E. Jorgensen -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20140217172017.GA9715@hawking
