[PVE-User] software RAID in 4.2

[Eneko Lacunza]

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?

Cheers

>
> Thanks!
>
> Miguel
>
>
>
>
>
>
> On 01/24/17 9:04 AM, Eneko Lacunza wrote:
>> Miguel,
>>
>> You have trouble with writes or reads?
>>
>>  From Proxmox or from a guest VM?
>>
>> El 23/01/17 a las 19:39, Miguel González escribió:
>>> Sorry I meant reads, pveperf:
>>>
>>> root at myserver:~# pveperf /vz/
>>> CPU BOGOMIPS:      42669.12
>>> REGEX/SECOND:      935261
>>> HD SIZE:           1809.50 GB (/dev/mapper/pve-data)
>>> BUFFERED READS:    94.56 MB/sec
>>> AVERAGE SEEK TIME: 17.88 ms
>>> FSYNCS/SECOND:     10.15
>>> DNS EXT:           16.93 ms
>>> DNS INT:           23.36 ms (ibertrix-node2)
>>>
>>>
>>> from specs from the manufacturer average seek time is around 8 ms
>>>
>>> writes are like this:
>>>
>>> root at myserver:~# dd if=/dev/zero of=/mytempfile
>>> ^C15210305+0 records in
>>> 15210305+0 records out
>>> 7787676160 bytes (7.8 GB) copied, 52.1116 s, 149 MB/s
>>>
>>>
>>> performance from a VM (I have 5 VMs running in this 32 Gb RAM server)
>>> running Centos 6.8:
>>>
>>> root at vm [~]# dd if=/dev/zero of=/mytempfile
>>> ^C9360176+0 records in
>>> 9360176+0 records out
>>> 4792410112 bytes (4.8 GB) copied, 112.571 s, 42.6 MB/s
>>>
>>> The settings for virtual HD are: qcow2 and writeback cache
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> On 01/23/17 7:02 PM, Mehmet wrote:
>>>> For datasafety i would not disable Barrier!
>>>>    But do you mean realy write Performance? As i know hdparm is used
>>>> for read Performance...
>>>>
>>>> Am 23. Januar 2017 18:57:19 MEZ schrieb Michael Rasmussen
>>>> <mir at miras.org>:
>>>>> On Mon, 23 Jan 2017 18:34:11 +0100
>>>>> Miguel González <miguel_3_gonzalez at yahoo.es> wrote:
>>>>>
>>>>>> Considering hdparm reports same speed for the underlying disk and the
>>>>>> soft raid seems some settings that need to be set. I´m asking here
>>>>> just
>>>>>> to be safe in terms of proxmox and not to be too aggressive. My
>>>>>> impression is that with ext3 I got better performance.
>>>>>>
>>>>> You can achieve the same performance and security level with ext4 as
>>>>> you did with ext3 by using this mount option: barrier=0
>>>>>
>>>>> -- 
>>>>> Hilsen/Regards
>>>>> Michael Rasmussen
>>>>>
>>>>> Get my public GnuPG keys:
>>>>> michael <at> rasmussen <dot> cc
>>>>> http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xD3C9A00E
>>>>> mir <at> datanom <dot> net
>>>>> http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xE501F51C
>>>>> mir <at> miras <dot> org
>>>>> http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xE3E80917
>>>>> --------------------------------------------------------------
>>>>> /usr/games/fortune -es says:
>>>>> You are here:
>>>>>          ***
>>>>>          ***
>>>>>           *********
>>>>>            *******
>>>>>             *****
>>>>>          ***
>>>>>           *
>>>>>
>>>>>           But you're not all there.
>>>> _______________________________________________
>>>> pve-user mailing list
>>>> pve-user at pve.proxmox.com
>>>> http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-user
>>>>
>>> _______________________________________________
>>> pve-user mailing list
>>> pve-user at pve.proxmox.com
>>> http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-user
>>
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