[zfs-discuss] Re: Copying a file from one ZFS to another starves all other processes
ryan at zbit.net.au
Wed May 22 02:50:01 EDT 2013
I've compiled against Ubuntu Raring Kernel (GIT Head).
Just has default kernel config + a few filesystems + network drivers +
Seems to be a bit more stable than it was before. But still get the same
issue. Maybe I should set up a straight ubuntu box and see if it works.
On a side note, if there any way to throttle a cp ?. Maybe if I throttle
it (I shouldn't have to!) at least it won't kill the system. ionice
doesn't seem to make any difference.
On 20/05/2013 10:50 AM, Ryan How wrote:
> BTW, I'm not overlaying ZFS with aufs or anything, they don't interact
> at all on the system.
> On 20/05/2013 10:47 AM, Ryan How wrote:
>> I'm running slackware 14.0, and am compiling ZOL with the "Generic
>> RPM" KMOD method. I've just downloaded the ubuntu raring kernel
>> sources and will try that. Most people seem to be using that and it
>> is working. I'm using Aufs too, so I need to compile a custom kernel
>> (But not doing any crazy configuration or anything). Seems that
>> ubuntu raring already has it patched in :)
>> Thanks, Ryan
>> On 19/05/2013 11:36 PM, RangerRick wrote:
>>> Hi Ryan,
>>> What version of Linux are you running? We have many hundreds of
>>> customers using ZOL with SoftNAS and have had no such issues with
>>> ZOL on CentOS 6.x.
>>> However, I have seen something similar to what you describe occur
>>> when files are copied to and from the LOCAL filesystem (non-ZFS)
>>> only on a ZOL system. Local filesystem caching appears to put
>>> pressure on available memory, which in turn causes what appears to
>>> be a lockup until that memory pressure is relieved. We have not
>>> observed this when the files being copied are ZFS to ZFS - only if
>>> done on the root filesystem, which is non-ZFS. As we do not use the
>>> root filesystem for file sharing, we do not encounter this in practice.
>>> On Friday, May 17, 2013 11:29:32 PM UTC-5, Ryan How wrote:
>>> With all the ZFS problems I'm having, it seems that it must be a
>>> with my kernel or something, coz otherwise I'm sure there would
>>> be a lot
>>> more people posting issues on the mailing list and a lot less
>>> using ZOL!
>>> They all almost seem related to I/O scheduling and buffering
>>> (well the
>>> symptoms of it, not sure what the actual problem is)
>>> One of the problems I'm having is when copying a file (cp fileA
>>> it basically starves everything else. Then my VMs (running as file
>>> backed storage directly on ZFS) get corrupt filesystems
>>> reporting that
>>> the disk controller was not responding (I'm guessing because
>>> they are
>>> trying to write, get to response from the system, so the guest
>>> the virtual disk is faulty)
>>> Does anyone else get anything like this?
>>> When copying as well, all the zfs commands are slow to respond (eg.
>>> zpool iostat takes a few seconds to spit out any info)
>>> Not using dedup or compression, machine has 32GB ram of which
>>> 6GB is
>>> currently free (after running for a few hours)
>>> I'm not really fussed if performance is slow (but performance is
>>> actually quite good), but if I am doing more than 1 disk related
>>> at a time it is kinda useless.
>>> Thanks, Ryan
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the zfs-discuss