From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: Spontaneous rebuild Date: Mon, 3 Dec 2007 10:14:37 +1100 Message-ID: <18259.15453.811495.461016@notabene.brown> References: <475230AF.3010100@student.tuwien.ac.at> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: message from Oliver Martin on Sunday December 2 Sender: linux-raid-owner@vger.kernel.org To: Oliver Martin Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Sunday December 2, oliver.martin@student.tuwien.ac.at wrote: > > Anyway, the problems are back: To test my theory that everything is > alright with the CPU running within its specs, I removed one of the > drives while copying some large files yesterday. Initially, everything > seemed to work out nicely, and by the morning, the rebuild had finished. > Again, I unmounted the filesystem and ran badblocks -svn on the LVM. It > ran without gripes for some hours, but just now I saw md had started to > rebuild the array again out of the blue: > > Dec 1 20:04:49 quassel kernel: usb 4-5.2: reset high speed USB device > using ehci_hcd and address 4 > Dec 2 01:06:02 quassel kernel: md: data-check of RAID array md0 ^^^^^^^^^^ > Dec 2 01:06:02 quassel kernel: md: minimum _guaranteed_ speed: 1000 > KB/sec/disk. > Dec 2 01:06:02 quassel kernel: md: using maximum available idle IO > bandwidth (but not more than 200000 KB/sec) for data-check. ^^^^^^^^^^ > Dec 2 01:06:02 quassel kernel: md: using 128k window, over a total of > 488383936 blocks. > Dec 2 03:57:24 quassel kernel: usb 4-5.2: reset high speed USB device > using ehci_hcd and address 4 > This isn't a resync, it is a data check. "Dec 2" is the first Sunday of the month. You probably have a crontab entries that does echo check > /sys/block/mdX/md/sync_action early on the first Sunday of the month. I know that Debian does this. It is good to do this occasionally to catch sleeping bad blocks. NeilBrown