On Thu, Sep 9, 2021 at 4:12 PM Mathieu Valois <[email protected]> wrote:
> You can find attached the benchmarks on the host and guest. I find the > differences not so big though... > Host is using the gluster mount (/rhev/data-center/mnt/glusterSD/server:_path/...) or writing directly into the same filesystem used by gluster (/bricks/brick1/...)? If will help if you share output of lsblk and the command line used to run fio on the host. Comparing host and guest: seq-write: (groupid=0, jobs=4): err= 0: pid=294433: Thu Sep 9 14:30:14 2021 write: IOPS=151, BW=153MiB/s (160MB/s)(4628MiB/30280msec); 0 zone resets I guess the underlying storage is hard disk - 150 MiB/s is not bad but very low compared with fast SSD. seq-read: (groupid=1, jobs=4): err= 0: pid=294778: Thu Sep 9 14:30:14 2021 read: IOPS=7084, BW=7086MiB/s (7430MB/s)(208GiB/30016msec) You have crazy caching (ignoring the direct I/O?), 7GiB/s read? rand-write-qd32: (groupid=2, jobs=4): err= 0: pid=295141: Thu Sep 9 14:30:14 2021 write: IOPS=228, BW=928KiB/s (951kB/s)(28.1MiB/30971msec); 0 zone resets Very low, probably limited by the hard disks? rand-read-qd32: (groupid=3, jobs=4): err= 0: pid=296094: Thu Sep 9 14:30:14 2021 read: IOPS=552k, BW=2157MiB/s (2262MB/s)(63.2GiB/30001msec) Very high, this is what you get from fast consumer SSD. rand-write-qd1: (groupid=4, jobs=1): err= 0: pid=296386: Thu Sep 9 14:30:14 2021 write: IOPS=55, BW=223KiB/s (229kB/s)(6696KiB/30002msec); 0 zone resets Very low. rand-read-qd1: (groupid=5, jobs=1): err= 0: pid=296633: Thu Sep 9 14:30:14 2021 read: IOPS=39.4k, BW=154MiB/s (161MB/s)(4617MiB/30001msec) Same caching. If we compare host and guest: $ grep -B1 IOPS= *.out guest.out-seq-write: (groupid=0, jobs=4): err= 0: pid=46235: Thu Sep 9 14:18:05 2021 guest.out: write: IOPS=57, BW=58.8MiB/s (61.6MB/s)(1792MiB/30492msec); 0 zone resets ~33% of host throughput guest.out-rand-write-qd32: (groupid=2, jobs=4): err= 0: pid=46330: Thu Sep 9 14:18:05 2021 guest.out: write: IOPS=299, BW=1215KiB/s (1244kB/s)(35.8MiB/30212msec); 0 zone resets Better than host guest.out-rand-write-qd1: (groupid=4, jobs=1): err= 0: pid=46552: Thu Sep 9 14:18:05 2021 guest.out: write: IOPS=213, BW=854KiB/s (875kB/s)(25.0MiB/30003msec); 0 zone resets Better than host So you have very fast reads (seq/random), with very slow seq/random write. Also would be interesting to test fsync - this benchmark does not do any fsync but your slow yum/rpm upgrade likey do one of more fsyncs per package upgrade. There is an example sync test script here: https://www.ibm.com/cloud/blog/using-fio-to-tell-whether-your-storage-is-fast-enough-for-etcd Le 09/09/2021 à 13:40, Nir Soffer a écrit : > > There are few issues with this test: > - you don't use oflag=direct or conv=fsync, so this may test copying data > to the host page cache, instead of writing data to storage > - This tests only sequential write, which is the best case for any kind of > storage > - Using synchronous I/O - every write wait for the previous write > completion > - Using single process > - 2g is too small, may test your cache performance > > Try to test using fio - attached fio script that tests sequential and > random io with > various queue depth. > > You can use it like this: > > fio --filename=/path/to/fio.data --output=test.out bench.fio > > Test both on the host, and in the VM. This will give you more detailed > results that may help to evaluate the issue, and it may help Gluster > folks to advise on tuning your storage. > > Nir > > -- > [image: téïcée] <https://www.teicee.com/?pk_campaign=Email> *Mathieu > Valois* > > Bureau Caen: Quartier Kœnig - 153, rue Géraldine MOCK - 14760 > Bretteville-sur-Odon > Bureau Vitré: Zone de la baratière - 12, route de Domalain - 35500 Vitré > 02 72 34 13 20 | www.teicee.com > <https://www.teicee.com/?pk_campaign=Email> > [image: téïcée sur facebook] <https://www.facebook.com/teicee> [image: > téïcée sur twitter] <https://twitter.com/Teicee_fr> [image: téïcée sur > linkedin] <https://www.linkedin.com/company/t-c-e> [image: téïcée sur > viadeo] <https://fr.viadeo.com/fr/company/teicee> [image: Datadocké] >
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