On 01/26/2014 02:37 AM, Steve Dainard wrote:
Thanks for the responses everyone, really appreciate it.2048000000 <tel:2048000000> bytes (2.0 GB) copied, 100.076 s, 20.5 MB/s
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, 4.99367 s, 410 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, 42.4518 s, 48.2 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, 18.8911 s, 108 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
2097152000 <tel:2097152000> bytes (2.1 GB) copied, 19.1089 s, 110 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
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/
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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.