[OpenIndiana-discuss] ZFS stalls with oi_151?

[Michael Stapleton]

Hi,

I had similar hard lockups when I accidentally tried to delete a ZFS
Volume while doing a ZFS send at the same time.
There seems to be a missing lock.

In the end I had to ensure that I did not run concurrent zfs commands. 

Are there any other ZFS commands hung at the same time?


Mike

On Fri, 2011-10-21 at 10:16 +0200, Tommy Eriksen wrote:

> Hi guys,
> 
> I've got a bit of a ZFS problem:
> All of a sudden, and it doesn't seem related to load or anything, the system will stop writing to the disks in my storage pool. No error messages are logged (that I can find anyway), nothing in dmesg, messages or the likes. 
> 
> ZFS stalls, a simple snapshot command (or the likes) just hangs indefinitely and can't be stopped with ctrl+c or kill -9.
> 
> Today, the stall happened after I had been running 2 VMs on each (running on vsphere5 connecting via iscsi) running iozone -s 200G (just to generate a bunch of load). Happily, this morning, I saw that they were still running without problem and stopped them. Then, when asking vSphere to delete the VMs, all write I/O stalled. A bit too much irony for me :)
> 
> However, and this puzzled me, everything else seems to run perfectly, even up to zfs writing new data on the l2arc devices while data is read.
> 
> Boxes (2 of the same) are:
> Supermicro based, 24 bay chassis
> 2*X5645 Xeon
> 48gigs of RAM
> 3*LSI2008 controllers coupled to
> 20 Seagate Constellation ES 3TB SATA
> 2 Intel 600GB SSD
> 2 Intel 311 20GB SSD
> 
> 18 of the 3TB drives are set up in mirrored vdevs, the last 2 are spares.
> 
> Running oi_151a (trying a downgrade to 148 today, I think, since I have 5 or so boxes running without problems on 148, but both my 151a are playing up).
> 
> /etc/system variables:
> set zfs:zfs_vdev_max_pending = 4
> set zfs:l2arc_noprefetch = 0
> set zfs:zfs_vdev_cache_size = 0
> 
> 
> I can write to a (spare) disk on the same controller without errors, so I take it its not a general I/O stall on the controller:
> root at zfsnas3:/var/adm# dd if=/dev/zero of=/dev/rdsk/c8t5000C50035DE14FAd0s0 bs=1M
> ^C1640+0 records in
> 1640+0 records out
> 1719664640 bytes (1.7 GB) copied, 11.131 s, 154 MB/s
> 
> iostat reported - note no writes to any of the other drives. All writes just stall.
> 
>                            extended device statistics       ---- errors --- 
>    r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b s/w h/w trn tot device
> 3631.6  167.2 14505.5 152337.1  0.0  2.2    0.0    0.6   0 157   0   0   0   0 c8
>  109.0    0.8  472.9    0.0  0.0  0.0    0.0    0.5   0   3   0   0   0   0 c8t5000C50035B922CCd0
>  143.0    0.8  567.1    0.0  0.0  0.1    0.0    0.5   0   3   0   0   0   0 c8t5000C50035CA8A5Cd0
>   89.6    0.8  414.1    0.0  0.0  0.1    0.0    0.6   0   2   0   0   0   0 c8t5000C50035CAB258d0
>   95.8    0.8  443.3    0.0  0.0  0.0    0.0    0.5   0   2   0   0   0   0 c8t5000C50035DE3DEBd0
>  144.8    0.8  626.4    0.0  0.0  0.1    0.0    0.6   0   4   0   0   0   0 c8t5000C50035BE1945d0
>  134.0    0.8  505.7    0.0  0.0  0.0    0.0    0.4   0   3   0   0   0   0 c8t5000C50035DDB02Ed0
>    1.0    0.4    3.4    0.0  0.0  0.0    0.0    0.0   0   0   0   0   0   0 c8t5000C50035DE0414d0
>  107.8    0.8  461.6    0.0  0.0  0.0    0.0    0.3   0   2   0   0   0   0 c8t5000C50035D40D15d0
>  117.2    0.8  516.5    0.0  0.0  0.1    0.0    0.5   0   3   0   0   0   0 c8t5000C50035DE0C86d0
>   64.2    0.8  261.2    0.0  0.0  0.0    0.0    0.6   0   2   0   0   0   0 c8t5000C50035DD6044d0
>    2.0    0.8    6.8    0.0  0.0  0.0    0.0    0.0   0   0   0   0   0   0 c8t5001517959582943d0
>    2.0    0.8    6.8    0.0  0.0  0.0    0.0    0.0   0   0   0   0   0   0 c8t5001517959582691d0
>  109.8    0.8  423.5    0.0  0.0  0.0    0.0    0.3   0   2   0   0   0   0 c8t5000C50035C13A6Bd0
>  765.0    0.8 3070.9    0.0  0.0  0.2    0.0    0.2   0   7   0   0   0   0 c8t5001517959699FE0d0
>    1.0  149.2    3.4 152337.1  0.0  1.0    0.0    6.5   0  97   0   0   0   0 c8t5000C50035DE14FAd0
>  210.4    0.8  775.4    0.0  0.0  0.1    0.0    0.4   0   3   0   0   0   0 c8t5000C50035CA1E58d0
>  689.4    0.8 2776.6    0.0  0.0  0.1    0.0    0.2   0   7   0   0   0   0 c8t50015179596A8717d0
>  108.6    0.8  430.5    0.0  0.0  0.0    0.0    0.4   0   2   0   0   0   0 c8t5000C50035CBD12Ad0
>  165.6    0.8  561.5    0.0  0.0  0.1    0.0    0.4   0   3   0   0   0   0 c8t5000C50035CA90DDd0
>  164.4    0.8  578.5    0.0  0.0  0.1    0.0    0.4   0   4   0   0   0   0 c8t5000C50035DDFC34d0
>  125.6    0.8  477.7    0.0  0.0  0.0    0.0    0.4   0   2   0   0   0   0 c8t5000C50035DE2AD3d0
>   93.2    0.8  371.3    0.0  0.0  0.0    0.0    0.4   0   2   0   0   0   0 c8t5000C50035B94C40d0
>  113.2    0.8  445.3    0.0  0.0  0.1    0.0    0.5   0   3   0   0   0   0 c8t5000C50035BA02AEd0
>   75.4    0.8  304.8    0.0  0.0  0.0    0.0    0.4   0   2   0   0   0   0 c8t5000C50035DDA579d0
> 
> 
> …Is anyone else seeing similar?
> 
> Thanks a lot,
> Tommy
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