[linux-lvm] problem with lvcreate and redirection of stdout/stderr

[Lentes, Bernd]

Alasdair wrote:

>
> On Wed, Aug 20, 2014 at 05:27:52PM +0200, Lentes, Bernd wrote:
> > lvcreate -v -L 45G -n lv_root_snapshot -s vg1/lv_root >>
> > /var/log/update.log 2>&1
>
> > lvcreate    Suspending vg1-lv_root (252:0) with filesystem sync with device
> flush
>
> /var/log is presumably part of a filesystem on the same LV that is getting its
> I/O paused for a brief moment while the snapshot is taken.
>

Yes it is. I have just one lv for the whole directory / .

> 1) Run lvm dumpconfig log/activation  to double-check this is not set to 1.

log {
        verbose=2
        syslog=0
        file="/var/log/lvm2.log"
        overwrite=0
        level=5
        indent=1
        command_names=1
        prefix="  "
}

activation {
        missing_stripe_filler="/dev/ioerror"
        reserved_stack=256
        reserved_memory=8192
        process_priority=-18
        mirror_region_size=512
        readahead="auto"
        monitoring=1
        mirror_log_fault_policy="allocate"
        mirror_device_fault_policy="remove"
        thin_pool_autoextend_threshold=100
        thin_pool_autoextend_percent=20
        udev_rules=1
        udev_sync=1
}


>
> 2) What filesystem is this and precisely what kernel?  (cat /proc/mounts)

FS is ext3, kernel is 3.0.76-0.11-default

vm58820-6:~ # cat /proc/mounts
rootfs / rootfs rw 0 0
udev /dev tmpfs rw,relatime,nr_inodes=0,mode=755 0 0
tmpfs /dev/shm tmpfs rw,relatime 0 0
/dev/mapper/vg1-lv_root / ext3 rw,relatime,errors=continue,user_xattr,acl,barrier=1,data=ordered 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,relatime 0 0
devpts /dev/pts devpts rw,relatime,gid=5,mode=620,ptmxmode=000 0 0
debugfs /sys/kernel/debug debugfs rw,relatime 0 0
/dev/vda3 /boot ext3 rw,relatime,errors=continue,user_xattr,acl,barrier=1,data=ordered 0 0
fusectl /sys/fs/fuse/connections fusectl rw,relatime 0 0
securityfs /sys/kernel/security securityfs rw,relatime 0 0
none /var/lib/ntp/proc proc ro,nosuid,nodev,relatime 0 0


>
> 3) Try to obtain a stack trace at the point where this locks up e.g.
> echo t > /proc/sysrq-trigger followed by dmesg (or divert your logging of
> kernel messages to a different filesystem outside the snapshot).
>
> Alasdair

the stack trace you find here (~190KB):  http://www.filedropper.com/stacktracevm58820-6lvcreate

Strange thing is that it worked now once without system stop. But second time stop again.


Thanks for your help.



Bernd

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