Re: [Users] Extremely poor disk access speeds in Windows guest

On 01/26/2014 02:37 AM, Steve Dainard wrote: > Thanks for the responses everyone, really appreciate it. > > I've condensed the other questions into this reply. > > > Steve, > What is the CPU load of the GlusterFS host when comparing the raw > brick test to the gluster mount point test? Give it 30 seconds and > see what top reports. You'll probably have to significantly increase > the count on the test so that it runs that long. > > - Nick > > > > Gluster mount point: > > *4K* on GLUSTER host > [root@gluster1 rep2]# dd if=/dev/zero of=/mnt/rep2/test1 bs=4k > count=500000 > 500000+0 records in > 500000+0 records out > 2048000000 <tel:2048000000> bytes (2.0 GB) copied, 100.076 s, 20.5 MB/s > > > Top reported this right away: > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 1826 root 20 0 294m 33m 2540 S 27.2 0.4 0:04.31 glusterfs > 2126 root 20 0 1391m 31m 2336 S 22.6 0.4 11:25.48 glusterfsd > > Then at about 20+ seconds top reports this: > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 1826 root 20 0 294m 35m 2660 R 141.7 0.5 1:14.94 glusterfs > 2126 root 20 0 1392m 31m 2344 S 33.7 0.4 11:46.56 glusterfsd > > *4K* Directly on the brick: > dd if=/dev/zero of=test1 bs=4k count=500000 > 500000+0 records in > 500000+0 records out > 2048000000 <tel:2048000000> bytes (2.0 GB) copied, 4.99367 s, 410 MB/s > > > 7750 root 20 0 102m 648 544 R 50.3 0.0 0:01.52 dd > 7719 root 20 0 0 0 0 D 1.0 0.0 0:01.50 flush-253:2 > > Same test, gluster mount point on OVIRT host: > dd if=/dev/zero of=/mnt/rep2/test1 bs=4k count=500000 > 500000+0 records in > 500000+0 records out > 2048000000 <tel:2048000000> bytes (2.0 GB) copied, 42.4518 s, 48.2 MB/s > > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 2126 root 20 0 1396m 31m 2360 S 40.5 0.4 13:28.89 glusterfsd > > > Same test, on OVIRT host but against NFS mount point: > dd if=/dev/zero of=/mnt/rep2-nfs/test1 bs=4k count=500000 > 500000+0 records in > 500000+0 records out > 2048000000 <tel:2048000000> bytes (2.0 GB) copied, 18.8911 s, 108 MB/s > > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 2141 root 20 0 550m 184m 2840 R 84.6 2.3 16:43.10 glusterfs > 2126 root 20 0 1407m 30m 2368 S 49.8 0.4 13:49.07 glusterfsd > > Interesting - It looks like if I use a NFS mount point, I incur a cpu > hit on two processes instead of just the daemon. I also get much better > performance if I'm not running dd (fuse) on the GLUSTER host. > > > The storage servers are a bit older, but are both dual socket > quad core > > opterons with 4x 7200rpm drives. > > > A block size of 4k is quite small so that the context switch > overhead involved with fuse would be more perceivable. > > Would it be possible to increase the block size for dd and test? > > > > I'm in the process of setting up a share from my desktop and > I'll see if > > I can bench between the two systems. Not sure if my ssd will > impact the > > tests, I've heard there isn't an advantage using ssd storage for > glusterfs. > > > Do you have any pointers to this source of information? Typically > glusterfs performance for virtualization work loads is bound by the > slowest element in the entire stack. Usually storage/disks happen to > be the bottleneck and ssd storage does benefit glusterfs. > > -Vijay > > > I had a couple technical calls with RH (re: RHSS), and when I asked if > SSD's could add any benefit I was told no. The context may have been in > a product comparison to other storage vendors, where they use SSD's for > read/write caching, versus having an all SSD storage domain (which I'm > not proposing, but which is effectively what my desktop would provide). > > Increasing bs against NFS mount point (gluster backend): > dd if=/dev/zero of=/mnt/rep2-nfs/test1 bs=128k count=16000 > 16000+0 records in > 16000+0 records out > 2097152000 <tel:2097152000> bytes (2.1 GB) copied, 19.1089 s, 110 MB/s > > > > GLUSTER host top reports: > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 2141 root 20 0 550m 183m 2844 R 88.9 2.3 17:30.82 glusterfs > 2126 root 20 0 1414m 31m 2408 S 46.1 0.4 14:18.18 glusterfsd > > So roughly the same performance as 4k writes remotely. I'm guessing if I > could randomize these writes we'd see a large difference. > > > Check this thread out, > http://raobharata.wordpress.com/2012/10/29/qemu-glusterfs- > native-integration/ it's > quite dated but I remember seeing similar figures. > > In fact when I used FIO on a libgfapi mounted VM I got slightly > faster read/write speeds than on the physical box itself (I assume > because of some level of caching). On NFS it was close to half.. > You'll probably get a little more interesting results using FIO > opposed to dd > > ( -Andrew) > > > Sorry Andrew, I meant to reply to your other message - it looks like > CentOS 6.5 can't use libgfapi right now, I stumbled across this info in > a couple threads. Something about how the CentOS build has different > flags set on build for RHEV snapshot support then RHEL, so native > gluster storage domains are disabled because snapshot support is assumed > and would break otherwise. I'm assuming this is still valid as I cannot > get a storage lock when I attempt a gluster storage domain. > > > ------------------------------------------------------------ > ------------------------------------------------------------ > ------------------------------------------------------------ > -------------------- > > I've setup a NFS storage domain on my desktops SSD. I've re-installed > win 2008 r2 and initially it was running smoother. > > Disk performance peaks at 100MB/s. > > If I copy a 250MB file from a share into the Windows VM, it writes out > quickly, less than 5 seconds. > > If I copy 20 files, ranging in file sizes from 4k to 200MB, totaling in > 650MB from the share - windows becomes unresponsive, in top the > desktop's nfs daemon is barely being touched at all, and then eventually > is not hit. I can still interact with the VM's windows through the spice > console. Eventually the file transfer will start and rocket through the > transfer. > > I've opened a 271MB zip file with 4454 files and started the extract > process but the progress windows will sit on 'calculating...' after a > significant period of time the decompression starts and runs at > <200KB/second. Windows is guesstimating 1HR completion time. Eventually > even this freezes up, and my spice console mouse won't grab. I can still > see the resource monitor in the Windows VM doing its thing but have to > poweroff the VM as its no longer usable. > > The windows update process is the same. It seems like when the guest > needs quick large writes its fine, but lots of io causes serious > hanging, unresponsiveness, spice mouse cursor freeze, and eventually > poweroff/reboot is the only way to get it back. > > Also, during window 2008 r2 install the 'expanding windows files' task > is quite slow, roughly 1% progress every 20 seconds (~30 mins to > complete). The GLUSTER host shows these stats pretty consistently: > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 8139 root 20 0 1380m 28m 2476 R 83.1 0.4 8:35.78 glusterfsd > 8295 root 20 0 550m 186m 2980 S 4.3 2.4 1:52.56 glusterfs > > bwm-ng v0.6 (probing every 2.000s), press 'h' for help > input: /proc/net/dev type: rate > \ iface Rx Tx > Total > > ============================================================ > ================== > lo: 3719.31 KB/s 3719.31 KB/s > 7438.62 KB/s > eth0: 3405.12 KB/s 3903.28 KB/s > 7308.40 KB/s > > > I've copied the same zip file to an nfs mount point on the OVIRT host > (gluster backend) and get about 25 - 600 KB/s during unzip. The same > test on NFS mount point (desktop SSD ext4 backend) averaged a network > transfer speed of 5MB/s and completed in about 40 seconds. > > I have a RHEL 6.5 guest running on the NFS/gluster backend storage > domain, and just did the same test. Extracting the file took 22.3 > seconds (faster than the fuse mount point on the host !?!?). > > GLUSTER host top reported this while the RHEL guest was decompressing > the zip file: > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 2141 root 20 0 555m 187m 2844 S 4.0 2.4 18:17.00 glusterfs > 2122 root 20 0 1380m 31m 2396 S 2.3 0.4 83:19.40 glusterfsd > > > > > > *Steve Dainard * > IT Infrastructure Manager > Miovision <http://miovision.com/> | /Rethink Traffic/ > 519-513-2407 <tel:519-513-2407> ex.250 > 877-646-8476 <tel:877-646-8476> (toll-free) > > *Blog <http://miovision.com/blog> | **LinkedIn > <https://www.linkedin.com/company/miovision-technologies> | Twitter > <https://twitter.com/miovision> | Facebook > <https://www.facebook.com/miovision>* > ------------------------------------------------------------------------ > Miovision Technologies Inc. | 148 Manitou Drive, Suite 101, Kitchener, > ON, Canada | N2C 1L3 > This e-mail may contain information that is privileged or confidential. > If you are not the intended recipient, please delete the e-mail and any > attachments and notify us immediately. > > > > > _______________________________________________ > Users mailing list > Users(a)ovirt.org > http://lists.ovirt.org/mailman/listinfo/users > > please note currently (>3.3.1), we don't use libgfapi on fedora as well, as we found some gaps in functionality in the libvirt libgfapi support for snapshots. once these are resolved, we can re-enable libgfapi on a glusterfs storage domain.