On 09/08/2011 02:25 AM, Nick wrote:
On 08/09/11 07:23, Emmett Culley wrote:
Today I suddenly have two VMs that have read only file systems. The host is CentOS 6, as are the two VMs with this problem.
Disclaimer: I can't claim this matches your circumstance exactly, but it is something you might check.
I have seen problems with LVM partitions in KVM guests being unwritable, despite being mounted read-write, on CentOS5.6 (host and guest). Specifically, I was booting a guest from the CentOS live CD in order to fix /etc/fstab on the root partition, which was LVM, but I could not save my changes.
Executing 'vgscan' resolved my problem; I'm not clear exactly why, but I could then remount and write successfully. You might also try 'vgchange -ay' if that doesn't work.
Perhaps:
- boot with liveCD .iso in a virtual CD drive
- check whether VolGroup-lv_root is mounted and writeable (use mount, lvdisplay, touch etc.)
- if not, unmount it, run vgscan
- remount it, and check for writability again
N
I will give that a try. However I remembered something about both failed VMs from my investigations yesterday and checked it out this morning on the one that is still available. The last lines of syslog (/var/log/messages) are:
Sep 6 19:42:49 dev squid[2885]: Ready to serve requests. Sep 6 19:42:50 dev squid[2885]: storeLateRelease: released 0 objects Sep 7 00:16:55 dev fail2ban.actions: WARNING [apache-pma] Ban 82.165.150.194 Sep 7 15:47:06 dev mountd[1658]: authenticated unmount request from 192.168.6.12:603 for /web (/web) Sep 7 15:49:33 dev mountd[1658]: authenticated mount request from 192.168.6.12:699 for /web (/web) Sep 7 15:49:34 dev mountd[1658]: authenticated mount request from 192.168.6.12:863 for /web (/web) Sep 7 21:19:59 dev init: tty (/dev/tty1) main process ended, respawning Sep 7 21:59:23 dev kernel: ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen Sep 7 21:59:23 dev kernel: ata1.00: failed command: WRITE DMA Sep 7 21:59:23 dev kernel: ata1.00: cmd ca/00:08:a0:02:31/00:00:00:00:00/e3 tag 0 dma 4096 out Sep 7 21:59:23 dev kernel: res 40/00:01:00:00:00/00:00:00:00:00/a0 Emask 0x4 (timeout) Sep 7 21:59:23 dev kernel: ata1.00: status: { DRDY } Sep 7 21:59:23 dev kernel: ata1: soft resetting link Sep 7 21:59:23 dev kernel: ata1.00: configured for MWDMA2 Sep 7 21:59:23 dev kernel: ata1.00: device reported invalid CHS sector 0 Sep 7 21:59:23 dev kernel: ata1: EH complete
So it looks like there is a bug I can report. But where to report it? I don't see how it can be a CentOS 6 bug.
Emmett