Date: Wed, 17 Aug 2016 10:19:05 +0200 From: rainer@ultra-secure.de To: =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= <roger.pau@citrix.com> Cc: freebsd-xen@freebsd.org, owner-freebsd-xen@freebsd.org Subject: Re: Is it me or is FreeBSD slower on Xen than Linux? Message-ID: <599395934f751784b1f842ed3c8f879c@ultra-secure.de> In-Reply-To: <cff064d12c783cc6eebba4b56f063ba7@ultra-secure.de> References: <2a0a5ae2821551935de329b8665834be@ultra-secure.de> <20160816100605.la63x2ju5bmtdqhl@mac> <e62d4e94ec36fa859783ddc0aeb1aa28@ultra-secure.de> <20160816110759.6xlvxikw3tziahfd@mac> <c3a3a7da26cd1a6a114c03e823926272@ultra-secure.de> <20160816132938.d2i4u2y3scpzi2et@mac> <00D22384-BAA7-42E4-A486-4BE07562D011@sarenet.es> <8521aebaa093bcefe5956a71fd879140@ultra-secure.de> <872C5626-F58D-4F84-92AC-88B7352D1DDF@sarenet.es> <c6bdef83f2370173c067820565bf933e@ultra-secure.de> <20160816141826.56mxsgx6e7rynxqg@mac> <cff064d12c783cc6eebba4b56f063ba7@ultra-secure.de>
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Am 2016-08-16 16:24, schrieb rainer@ultra-secure.de:
> Am 2016-08-16 16:18, schrieb Roger Pau Monné:
>
>> I'm not saying it's not possible, but are you sure this slowdown is
>> caused
>> by the disk? It's certainly a possibility, but I would like to make
>> sure
>> it's caused by that before jumping into conclusions.
>>
>> Can you load the full database in RAM and perform the same test. TBH,
>> I
>> don't use MariaDB, so I'm not sure what's the best way to achieve
>> this, but
>> a quick search on google shows there are multiple ways. In any case,
>> make
>> sure with iostat that the database is not read from the disk.
>
> I'll try to do some disk-benchmarks, when I can attach some bigger
> disks.
on Ubuntu 14 with HVM:
dc3dd wipe=/dev/xvdc
dc3dd 7.1.614 started at 2016-08-17 09:38:17 +0200
compiled options:
command line: dc3dd wipe=/dev/xvdc
device size: 104857600 sectors (probed)
sector size: 512 bytes (probed)
53687091200 bytes (50 G) copied (100%), 464.642 s, 110 M/s
input results for pattern `00':
104857600 sectors in
output results for device `/dev/xvdc':
104857600 sectors out
dc3dd completed at 2016-08-17 09:46:01 +0200
On FreeBSD 10.3-RELEASE-p6 with HVM:
Aug 17 09:57:52 bla-prod kernel: xbd4: 51200MB <Virtual Block Device> at
device/vbd/51776 on xenbusb_front0
Aug 17 09:57:52 bla-prod kernel: xbd4: features: write_barrier
Aug 17 09:57:52 bla-prod kernel: xbd4: synchronize cache commands
enabled.
dc3dd wipe=/dev/xbd4
and it's showing 8.something MB/s
Is this normal?
What may I be doing wrong?
Rainer
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