[PVE-User] software RAID in 4.2

Miguel González miguel_3_gonzalez at yahoo.es
Mon Jan 30 10:15:32 CET 2017


On 01/24/17 10:22 AM, Eneko Lacunza wrote:
> Hi Miguel,
> 
> El 24/01/17 a las 10:11, Miguel González escribió:
>> Reads and in both, Proxmox and therefore in guest VMs.
>>
>> As you can see in my messages writes seem to be more or less fine around
>> 140 MB/s in Proxmox while reads are around 40 MB/s.
>>
>> At this point I don´t know if there is something related to hardware or
>> software, I have raised a ticket with support.
> 
> Ok, I don't think pveperf's "fsyncs/second" is good, it's way too low.
> 
> Also, 42MB/s isn't very good from VM, but maybe qcow2 is expanding the
> file there.
> 
> Re-reading your first post I think you have a hw/cabling issue. Does sdb
> give same hdparm results as sda?

Ok, suggested by support I took down all VMs and run the tests without
nothing running. I still find fsyncs low from time to time, which I
don´t understand, varying from 2-40 is a bit too much variation from my
point of view.


root at myserver:~# pveperf /vz/
CPU BOGOMIPS: 42667.60
REGEX/SECOND: 1099581
HD SIZE: 1809.50 GB (/dev/mapper/pve-data)
BUFFERED READS: 138.73 MB/sec
AVERAGE SEEK TIME: 18.94 ms
FSYNCS/SECOND: 1.97
DNS EXT: 17.82 ms
DNS INT: 13.27 ms (myserver)
root at myserver:~# pveperf /vz/
CPU BOGOMIPS: 42667.60
REGEX/SECOND: 1162253
HD SIZE: 1809.50 GB (/dev/mapper/pve-data)
BUFFERED READS: 123.24 MB/sec
AVERAGE SEEK TIME: 13.28 ms
FSYNCS/SECOND: 39.64
DNS EXT: 11.67 ms
DNS INT: 19.81 ms (myserver)
root at myserver:~# pveperf /vz/
CPU BOGOMIPS: 42667.60
REGEX/SECOND: 1123387
HD SIZE: 1809.50 GB (/dev/mapper/pve-data)
BUFFERED READS: 121.61 MB/sec
AVERAGE SEEK TIME: 13.83 ms
FSYNCS/SECOND: 22.67
DNS EXT: 14.01 ms
DNS INT: 13.90 ms (myserver)
root at myserver:~# pveperf /vz/
CPU BOGOMIPS: 42667.60
REGEX/SECOND: 1138502
HD SIZE: 1809.50 GB (/dev/mapper/pve-data)
BUFFERED READS: 100.28 MB/sec
AVERAGE SEEK TIME: 13.74 ms
FSYNCS/SECOND: 41.03
DNS EXT: 13.72 ms
DNS INT: 12.70 ms (myserver)
root at myserver:~# pveperf /vz/
CPU BOGOMIPS: 42667.60
REGEX/SECOND: 1102421
HD SIZE: 1809.50 GB (/dev/mapper/pve-data)
BUFFERED READS: 134.41 MB/sec
AVERAGE SEEK TIME: 12.74 ms
FSYNCS/SECOND: 30.34
DNS EXT: 11.25 ms
DNS INT: 14.16 ms (myserver)
root at myserver:~# hdparm -tT /dev/sda

/dev/sda:
Timing cached reads: 16160 MB in 2.00 seconds = 8087.23 MB/sec
Timing buffered disk reads: 434 MB in 3.00 seconds = 144.60 MB/sec
root at myserver:~# hdparm -tT /dev/sdb

/dev/sdb:
Timing cached reads: 16492 MB in 2.00 seconds = 8253.77 MB/sec
Timing buffered disk reads: 456 MB in 3.01 seconds = 151.44 MB/sec



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