Mailing List Archive: DRBD: Users

drbd performance issue on SATA

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francois.delpierre at pivert

Jan 1, 2012, 9:04 AM

Post #1 of 11 (771 views)
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drbd performance issue on SATA

Hi,

I'm building a very low cost virtualization server for a Non Profit organization using 2 HP workstations (500€ each) (8GB Ram, 1.5TB, QuadCore AMD), Software Proxmox and DRBD for the data replication with dedicated gigabit & cross cable for the replication.

After setting up the replication (Protocol C), I had catastrophic performances, ( dropping to 30 IOPS after 60s of random writes ).

I also found a lot of reading, not fully explaining my terrific 30 IOPS on 7200RPM drives, but clearly pointing the necessity to have a battery backed up cache controller to sustain random writes generated by the meta-disk.

As the hardware makrket did change quite a lot recently, especially towards SSD, I immediately realized that 240GB SSD are half price than a small raid controller, a battery for the cache, and 2 small disks with reasonable performances (10rpm). So, I choose SSD.

I created 2 partitions on my SSD :
- 128MB for external meta-disk of my slow SATA partition (750GB)
- 240GB for a second DRBD resource, with internal meta-disk.

My questions :
- Is there some recommendations on a SSD setup ?
- Why is the external meta-disk that few documented ? I spent more than 1 hour to find the syntax of the directive :

meta-disk /dev/disk/by-id/scsi-SATA_MKNSSDCR240GB_MKN1146A0000032XXX-part1[0];

And it's not clear to my what is the [0] at the end ?

Regards,

François Delpierre

ediazrod at gmail

Jan 3, 2012, 5:19 AM

Post #2 of 11 (743 views)
Permalink

Re: drbd performance issue on SATA [In reply to]

I check the Network link too, because some times the network are the
real problem.

Did you test the network interface?.

Did you change the the protocol to A for example.. and make more test.

In my experience the SSD disk has problems for broken.

http://www.codinghorror.com/blog/2011/05/the-hot-crazy-solid-state-drive-scale.html

What configuration are you creating? Active/active, Active/passive?
What filesystem?

regards!

On Sun, Jan 1, 2012 at 6:04 PM, François Delpierre
<francois.delpierre [at] pivert> wrote:
> Hi,
>
> I'm building a very low cost virtualization server for a Non Profit
> organization using 2 HP workstations (500€ each) (8GB Ram, 1.5TB, QuadCore
> AMD), Software Proxmox and DRBD for the data replication with dedicated
> gigabit & cross cable for the replication.
>
> After setting up the replication (Protocol C), I had catastrophic
> performances, ( dropping to 30 IOPS after 60s of random writes ).
>
> I also found a lot of reading, not fully explaining my terrific 30 IOPS on
> 7200RPM drives, but clearly pointing the necessity to have a battery backed
> up cache controller to sustain random writes generated by the meta-disk.
>
> As the hardware makrket did change quite a lot recently, especially towards
> SSD, I immediately realized that 240GB SSD are half price than a small raid
> controller, a battery for the cache, and 2 small disks with reasonable
> performances (10rpm). So, I choose SSD.
>
> I created 2 partitions on my SSD :
> - 128MB for external meta-disk of my slow SATA partition (750GB)
> - 240GB for a second DRBD resource, with internal meta-disk.
>
> My questions :
> - Is there some recommendations on a SSD setup ?
> - Why is the external meta-disk that few documented ? I spent more than 1
> hour to find the syntax of the directive :
>
> meta-disk
> /dev/disk/by-id/scsi-SATA_MKNSSDCR240GB_MKN1146A0000032XXX-part1[0];
>
> And it's not clear to my what is the [0] at the end ?
>
> Regards,
>
> François Delpierre
>
>
> _______________________________________________
> drbd-user mailing list
> drbd-user [at] lists
> http://lists.linbit.com/mailman/listinfo/drbd-user
>
_______________________________________________
drbd-user mailing list
drbd-user [at] lists
http://lists.linbit.com/mailman/listinfo/drbd-user

francois.delpierre at pivert

Jan 4, 2012, 4:18 AM

Post #3 of 11 (746 views)
Permalink

Re: drbd performance issue on SATA [In reply to]

I noticed I did not reply to the list. So, here is the copy :

Hi Eduardo,

When I had these horrible performances I was not in a good situations :
- One 2GB disk SSD 7200RPM per node.
- DRBD 8.3, Protocol C, Active-Active
- 2 Network interfaces on a 100Mbits network switch.

Now that I added the SSDs, I'll test again. I'm currently looking on how to test.
As I'm not interested in testing my OS cache, I'll reduce the memory to 1GB or less (with the mem=1024M kernel boot option), Install an ubuntu VM with 512MRam and PV disk drivers, and run either bonnie++ or iozone in these 4 conditions :
- Local SSD
- DRBD SSD in Active-Active
- Local SATA
- DRBD Sata in Active-Active (but with the meta-disk on SSD). (Where I was getting 30IOPS with bonnie++ in my VM before I moved meta-disk to SSD)

Regards,
François Delpierre

----- Mail original -----

De: "Eduardo Diaz - Gmail" <ediazrod [at] gmail>
À: "François Delpierre" <francois.delpierre [at] pivert>
Cc: drbd-user [at] lists
Envoyé: Mardi 3 Janvier 2012 14:19:39
Objet: Re: [DRBD-user] drbd performance issue on SATA

I check the Network link too, because some times the network are the
real problem.

Did you test the network interface?.

Did you change the the protocol to A for example.. and make more test.

In my experience the SSD disk has problems for broken.

http://www.codinghorror.com/blog/2011/05/the-hot-crazy-solid-state-drive-scale.html

What configuration are you creating? Active/active, Active/passive?
What filesystem?

regards!

On Sun, Jan 1, 2012 at 6:04 PM, François Delpierre
<francois.delpierre [at] pivert> wrote:
> Hi,
>
> I'm building a very low cost virtualization server for a Non Profit
> organization using 2 HP workstations (500€ each) (8GB Ram, 1.5TB, QuadCore
> AMD), Software Proxmox and DRBD for the data replication with dedicated
> gigabit & cross cable for the replication.
>
> After setting up the replication (Protocol C), I had catastrophic
> performances, ( dropping to 30 IOPS after 60s of random writes ).
>
> I also found a lot of reading, not fully explaining my terrific 30 IOPS on
> 7200RPM drives, but clearly pointing the necessity to have a battery backed
> up cache controller to sustain random writes generated by the meta-disk.
>
> As the hardware makrket did change quite a lot recently, especially towards
> SSD, I immediately realized that 240GB SSD are half price than a small raid
> controller, a battery for the cache, and 2 small disks with reasonable
> performances (10rpm). So, I choose SSD.
>
> I created 2 partitions on my SSD :
> - 128MB for external meta-disk of my slow SATA partition (750GB)
> - 240GB for a second DRBD resource, with internal meta-disk.
>
> My questions :
> - Is there some recommendations on a SSD setup ?
> - Why is the external meta-disk that few documented ? I spent more than 1
> hour to find the syntax of the directive :
>
> meta-disk
> /dev/disk/by-id/scsi-SATA_MKNSSDCR240GB_MKN1146A0000032XXX-part1[0];
>
> And it's not clear to my what is the [0] at the end ?
>
> Regards,
>
> François Delpierre
>
>
> _______________________________________________
> drbd-user mailing list
> drbd-user [at] lists
> http://lists.linbit.com/mailman/listinfo/drbd-user
>

drbd at pivert

Jan 4, 2012, 6:40 AM

Post #4 of 11 (744 views)
Permalink

Re: drbd performance issue on SATA [In reply to]

Here are the stats results with Bonnie++, in HTML format (see attachment)
The first 4 tests are in VM.
The 2 last are just test on 2 workstations with similar options. An entry level one and a high end one, both with SSDs. DRBD is of course not used there.

Test command :
-------------------
bonnie++ -d ./scratchdir/ -c 2 -s 2G -n 64:4096:512 (Changed to -s 16G on my high end workstation )

Virtualization software and Hardware for the first 4 tests (localssd1, ssdvg1, localdir, satavg1) :
------------------------------------------------------------------------------------------------------------------------

- Virtulization : Proxmox VE 1.9 (KVM) + VirtIO network & disk drivers, 10GB Storage and 256MB Ram
- Hardware : 2 HP Pavilion G5415be workstation with QuadCore Athlon X4 645 3.2GHz+ SSD Chronos SA3 MSK 240GB ( in SATA2 mode because of Mother board ) - Limited to 1GB of Ram with the mem=1024M boot option.
- Additional GBits PCIe 1X network adapters with a cross cable dedicated to DRBD replication (when used).

Test conditions (rest of Stack description ):
localssd1
=======
- VM OS : Ubuntu 11.10 Server with default options (ext4)
- VM Storage : LVM on (SSD PV of 40GB)

ssdvg1
=====

- VM OS : Ubuntu 11.10 Server with default options (ext4) with 256MB Ram
- VM Storage : LVM on DRBD Active-Active (Protocol C) (SSD PV of 200GB in each server)

localdir
=====

- VM OS : Ubuntu 11.10 Server with default options (ext4) with 256MB Ram
- VM Storage : RAW Image on a local SATA disk (2TB/7200RPM) formated in EXT3

satavg1
=====

- VM OS : Ubuntu 11.10 Server with default options (ext4) with 256MB Ram
- VM Storage : LVM on DRBD Active-Active (Protocol C) (SATA disk 2TB/7200RPM PV of 750GB in each server) - With Meta-Disk on a small partition of 128MB on the

skinner
=====
- Not a VM, just my workstation, a very light workstation with 2GB Ram, Dual Core ATOM 1.8GHz, and OCZ Vertex2 SSD.
- Kubuntu 11.10 on ext4

westvleteren
=========
- Not a VM, an other workstation, high end, with 8GB Ram, Quad Core intel Corei5, SSD 120GB SATA3 ( more than 500MB/s read/writes with 90000 IOPS )

Conclusions :
-----------------
- on the satavg1 test, using meta-disk on SSD did not fix my problem. Maybe it's better than meta-disk internal, but clearly unusable. Machine unresponsive, host with load of 10 during the test in the VM, ... So unfortunately, SSD meta-disk did not save my 750GB partitions from being far too slow to be used.

- on the ssdvg1, the performances, are really good. Strangely, it even competes to the results without DRBD (localssd1). The move to SSD for my VMs seems to fix my issue. My totally useless cluster on SATA Drives, becomes now really usable with SSD.

As all my VMs can keep into 200GB storage. My performance problem is fixed, it's even really good.

Regards,

François

I noticed I did not reply to the list. So, here is the copy :

Hi Eduardo,

When I had these horrible performances I was not in a good situations :
- One 2GB disk SSD 7200RPM per node.
- DRBD 8.3, Protocol C, Active-Active
- 2 Network interfaces on a 100Mbits network switch.

Now that I added the SSDs, I'll test again. I'm currently looking on how to test.
As I'm not interested in testing my OS cache, I'll reduce the memory to 1GB or less (with the mem=1024M kernel boot option), Install an ubuntu VM with 512MRam and PV disk drivers, and run either bonnie++ or iozone in these 4 conditions :
- Local SSD
- DRBD SSD in Active-Active
- Local SATA
- DRBD Sata in Active-Active (but with the meta-disk on SSD). (Where I was getting 30IOPS with bonnie++ in my VM before I moved meta-disk to SSD)

Regards,
François Delpierre
----- Mail original -----

De: "Eduardo Diaz - Gmail" <ediazrod [at] gmail>
À: "François Delpierre" <francois.delpierre [at] pivert>
Cc: drbd-user [at] lists
Envoyé: Mardi 3 Janvier 2012 14:19:39
Objet: Re: [DRBD-user] drbd performance issue on SATA

I check the Network link too, because some times the network are the
real problem.

Did you test the network interface?.

Did you change the the protocol to A for example.. and make more test.

In my experience the SSD disk has problems for broken.

http://www.codinghorror.com/blog/2011/05/the-hot-crazy-solid-state-drive-scale.html

What configuration are you creating? Active/active, Active/passive?
What filesystem?

regards!

On Sun, Jan 1, 2012 at 6:04 PM, François Delpierre
<francois.delpierre [at] pivert> wrote:

Hi,

I'm building a very low cost virtualization server for a Non Profit
organization using 2 HP workstations (500€ each) (8GB Ram, 1.5TB, QuadCore
AMD), Software Proxmox and DRBD for the data replication with dedicated
gigabit & cross cable for the replication.

After setting up the replication (Protocol C), I had catastrophic
performances, ( dropping to 30 IOPS after 60s of random writes ).

I also found a lot of reading, not fully explaining my terrific 30 IOPS on
7200RPM drives, but clearly pointing the necessity to have a battery backed
up cache controller to sustain random writes generated by the meta-disk.

As the hardware makrket did change quite a lot recently, especially towards
SSD, I immediately realized that 240GB SSD are half price than a small raid
controller, a battery for the cache, and 2 small disks with reasonable
performances (10rpm). So, I choose SSD.

I created 2 partitions on my SSD :
- 128MB for external meta-disk of my slow SATA partition (750GB)
- 240GB for a second DRBD resource, with internal meta-disk.

My questions :
- Is there some recommendations on a SSD setup ?
- Why is the external meta-disk that few documented ? I spent more than 1
hour to find the syntax of the directive :

meta-disk
/dev/disk/by-id/scsi-SATA_MKNSSDCR240GB_MKN1146A0000032XXX-part1[0];

And it's not clear to my what is the [0] at the end ?

Regards,

François Delpierre

_______________________________________________
drbd-user mailing list
drbd-user [at] lists
http://lists.linbit.com/mailman/listinfo/drbd-user

Attachments:

bonnie_results.html (12.4 KB)

ediazrod at gmail

Jan 4, 2012, 3:08 PM

Post #5 of 11 (751 views)
Permalink

Re: drbd performance issue on SATA [In reply to]

Hi, don't have a 1Gb network??? you "need" a 1GB network at least
because the 100 is veryyyyy slow... for a speed configuration...

Now I have a Active-Active (what filesystem are you using? ocfs2??),
If you send me the test that you make I can run in my own server...
(somthink ease, please :) ).

On Wed, Jan 4, 2012 at 1:18 PM, François Delpierre
<francois.delpierre [at] pivert> wrote:
> I noticed I did not reply to the list. So, here is the copy :
>
> Hi Eduardo,
>
> When I had these horrible performances I was not in a good situations :
> - One 2GB disk SSD 7200RPM per node.
> - DRBD 8.3, Protocol C, Active-Active
> - 2 Network interfaces on a 100Mbits network switch.
>
> Now that I added the SSDs, I'll test again. I'm currently looking on how to
> test.
> As I'm not interested in testing my OS cache, I'll reduce the memory to 1GB
> or less (with the mem=1024M kernel boot option), Install an ubuntu VM with
> 512MRam and PV disk drivers, and run either bonnie++ or iozone in these 4
> conditions :
> - Local SSD
> - DRBD SSD in Active-Active
> - Local SATA
> - DRBD Sata in Active-Active (but with the meta-disk on SSD). (Where I was
> getting 30IOPS with bonnie++ in my VM before I moved meta-disk to SSD)
>
> Regards,
>
> François Delpierre
>
> ________________________________
> De: "Eduardo Diaz - Gmail" <ediazrod [at] gmail>
> À: "François Delpierre" <francois.delpierre [at] pivert>
> Cc: drbd-user [at] lists
> Envoyé: Mardi 3 Janvier 2012 14:19:39
> Objet: Re: [DRBD-user] drbd performance issue on SATA
>
> I check the Network link too, because some times the network are the
> real problem.
>
> Did you test the network interface?.
>
> Did you change the the protocol to A for example.. and make more test.
>
> In my experience the SSD disk has problems for broken.
>
> http://www.codinghorror.com/blog/2011/05/the-hot-crazy-solid-state-drive-scale.html
>
> What configuration are you creating? Active/active, Active/passive?
> What filesystem?
>
> regards!
>
> On Sun, Jan 1, 2012 at 6:04 PM, François Delpierre
> <francois.delpierre [at] pivert> wrote:
>> Hi,
>>
>> I'm building a very low cost virtualization server for a Non Profit
>> organization using 2 HP workstations (500€ each) (8GB Ram, 1.5TB, QuadCore
>> AMD), Software Proxmox and DRBD for the data replication with dedicated
>> gigabit & cross cable for the replication.
>>
>> After setting up the replication (Protocol C), I had catastrophic
>> performances, ( dropping to 30 IOPS after 60s of random writes ).
>>
>> I also found a lot of reading, not fully explaining my terrific 30 IOPS on
>> 7200RPM drives, but clearly pointing the necessity to have a battery
>> backed
>> up cache controller to sustain random writes generated by the meta-disk.
>>
>> As the hardware makrket did change quite a lot recently, especially
>> towards
>> SSD, I immediately realized that 240GB SSD are half price than a small
>> raid
>> controller, a battery for the cache, and 2 small disks with reasonable
>> performances (10rpm). So, I choose SSD.
>>
>> I created 2 partitions on my SSD :
>> - 128MB for external meta-disk of my slow SATA partition (750GB)
>> - 240GB for a second DRBD resource, with internal meta-disk.
>>
>> My questions :
>> - Is there some recommendations on a SSD setup ?
>> - Why is the external meta-disk that few documented ? I spent more than 1
>> hour to find the syntax of the directive :
>>
>> meta-disk
>> /dev/disk/by-id/scsi-SATA_MKNSSDCR240GB_MKN1146A0000032XXX-part1[0];
>>
>> And it's not clear to my what is the [0] at the end ?
>>
>> Regards,
>>
>> François Delpierre
>>
>>
>> _______________________________________________
>> drbd-user mailing list
>> drbd-user [at] lists
>> http://lists.linbit.com/mailman/listinfo/drbd-user
>>
>
>
> _______________________________________________
> drbd-user mailing list
> drbd-user [at] lists
> http://lists.linbit.com/mailman/listinfo/drbd-user
>
_______________________________________________
drbd-user mailing list
drbd-user [at] lists
http://lists.linbit.com/mailman/listinfo/drbd-user

arnold at arnoldarts

Jan 4, 2012, 4:07 PM

Post #6 of 11 (736 views)
Permalink

Re: drbd performance issue on SATA [In reply to]

On Wednesday 04 January 2012 13:18:32 François Delpierre wrote:
> I noticed I did not reply to the list. So, here is the copy :
>
>
> Hi Eduardo,
>
>
> When I had these horrible performances I was not in a good situations :
> - One 2GB disk SSD 7200RPM per node.
> - DRBD 8.3, Protocol C, Active-Active
> - 2 Network interfaces on a 100Mbits network switch.

That will give you 12MB/s for drbd-io. Maybe 24 if trunked/bonded and your
switch does its job right (my hp-switch at home doesn't(*)).
Better not set your hopes to high with the ssd... Altough I never heard of an
ssd with revolutions-per-minute.

If you encounter low io performance (and you will unless your disks are way
old and PATA without DMA), invest that ~50€ and give each server a gigabit
card.

Have fun,

Arnold

Attachments:

signature.asc (0.19 KB)

ediazrod at gmail

Jan 5, 2012, 1:45 AM

Post #7 of 11 (730 views)
Permalink

Re: drbd performance issue on SATA [In reply to]

The cost of one PCI-E 1Gb card is for 10€, if you want use a Intel
good card, you cand speed 30€....

Change to 1G, this is you problem...

On Thu, Jan 5, 2012 at 1:07 AM, Arnold Krille <arnold [at] arnoldarts> wrote:
> On Wednesday 04 January 2012 13:18:32 François Delpierre wrote:
>> I noticed I did not reply to the list. So, here is the copy :
>>
>>
>> Hi Eduardo,
>>
>>
>> When I had these horrible performances I was not in a good situations :
>> - One 2GB disk SSD 7200RPM per node.
>> - DRBD 8.3, Protocol C, Active-Active
>> - 2 Network interfaces on a 100Mbits network switch.
>
> That will give you 12MB/s for drbd-io. Maybe 24 if trunked/bonded and your
> switch does its job right (my hp-switch at home doesn't(*)).
> Better not set your hopes to high with the ssd... Altough I never heard of an
> ssd with revolutions-per-minute.
>
> If you encounter low io performance (and you will unless your disks are way
> old and PATA without DMA), invest that ~50€ and give each server a gigabit
> card.
>
> Have fun,
>
> Arnold
>
> _______________________________________________
> drbd-user mailing list
> drbd-user [at] lists
> http://lists.linbit.com/mailman/listinfo/drbd-user
>
_______________________________________________
drbd-user mailing list
drbd-user [at] lists
http://lists.linbit.com/mailman/listinfo/drbd-user

drbd at pivert

Jan 6, 2012, 12:46 AM

Post #8 of 11 (719 views)
Permalink

Re: drbd performance issue on SATA [In reply to]

Hi,

Warning, I inserted a major confusion in my previous email.

When I wrote :
>> When I had these horrible performances I was not in a good situations :
>> - One 2GB disk SSD 7200RPM per node.
>> - DRBD 8.3, Protocol C, Active-Active
>> - 2 Network interfaces on a 100Mbits network switch.

This is of course SATA Magnetic/Mecanic drive. Thanks for pointing that SSD has to revolution per minute metrics.

I'm deeply sorry,

So, yes, the SSD completely changed the performances for this solution from a useless one to a working one.
And also, the Gigabit card is necessary to reach acceptable performances.
When you need fast resync, it's interesting to split your volumes in 2, to have 2 DRBD clusters :
with Cross-Cable, you always have the full duplex active, and if you cross sync 2 DRBD volume pairs, you can replicate at 90MB/s in one way, and 90MB/s the other way. (total 180MB/s for resyncing to DRBD volumes with one volume master on each node.)

Regards,

----- Mail original -----

De: "Eduardo Diaz - Gmail" <ediazrod [at] gmail>
À: "Arnold Krille" <arnold [at] arnoldarts>
Cc: drbd-user [at] lists
Envoyé: Jeudi 5 Janvier 2012 10:45:21
Objet: Re: [DRBD-user] drbd performance issue on SATA

The cost of one PCI-E 1Gb card is for 10€, if you want use a Intel
good card, you cand speed 30€....

Change to 1G, this is you problem...

On Thu, Jan 5, 2012 at 1:07 AM, Arnold Krille <arnold [at] arnoldarts> wrote:
> On Wednesday 04 January 2012 13:18:32 François Delpierre wrote:
>> I noticed I did not reply to the list. So, here is the copy :
>>
>>
>> Hi Eduardo,
>>
>>
>> When I had these horrible performances I was not in a good situations :
>> - One 2GB disk SSD 7200RPM per node.
>> - DRBD 8.3, Protocol C, Active-Active
>> - 2 Network interfaces on a 100Mbits network switch.
>
> That will give you 12MB/s for drbd-io. Maybe 24 if trunked/bonded and your
> switch does its job right (my hp-switch at home doesn't(*)).
> Better not set your hopes to high with the ssd... Altough I never heard of an
> ssd with revolutions-per-minute.
>
> If you encounter low io performance (and you will unless your disks are way
> old and PATA without DMA), invest that ~50€ and give each server a gigabit
> card.
>
> Have fun,
>
> Arnold
>
> _______________________________________________
> drbd-user mailing list
> drbd-user [at] lists
> http://lists.linbit.com/mailman/listinfo/drbd-user
>
_______________________________________________
drbd-user mailing list
drbd-user [at] lists
http://lists.linbit.com/mailman/listinfo/drbd-user

ff at mpexnet

Jan 6, 2012, 12:51 AM

Post #9 of 11 (714 views)
Permalink

Re: drbd performance issue on SATA [In reply to]

Hi,

On 01/06/2012 09:46 AM, François Delpierre wrote:
> you can replicate at 90MB/s in one way,

that's true, but it's advisable to use no more than 30% of your total
bandwidth for syncing, so that your DRBD write latency won't suffer.

Cheers,
Felix
_______________________________________________
drbd-user mailing list
drbd-user [at] lists
http://lists.linbit.com/mailman/listinfo/drbd-user

ediazrod at gmail

Jan 7, 2012, 1:48 AM

Post #10 of 11 (708 views)
Permalink

Re: drbd performance issue on SATA [In reply to]

Hi, please send to the list the final performance :-) too see how drbd
do "the job"...

On Fri, Jan 6, 2012 at 9:51 AM, Felix Frank <ff [at] mpexnet> wrote:
> Hi,
>
> On 01/06/2012 09:46 AM, François Delpierre wrote:
>> you can replicate at 90MB/s in one way,
>
> that's true, but it's advisable to use no more than 30% of your total
> bandwidth for syncing, so that your DRBD write latency won't suffer.
>
> Cheers,
> Felix
> _______________________________________________
> drbd-user mailing list
> drbd-user [at] lists
> http://lists.linbit.com/mailman/listinfo/drbd-user
_______________________________________________
drbd-user mailing list
drbd-user [at] lists
http://lists.linbit.com/mailman/listinfo/drbd-user

drbd at pivert

Jan 7, 2012, 3:41 AM

Post #11 of 11 (703 views)
Permalink

Re: drbd performance issue on SATA [In reply to]

Hi,

The stats did not change, and the description for the tests are good. Only the "2GB disk SSD 7200RPM" by "2TB HD SATA 7200RPM" .

For the bandwidth, my settings in the drbd config for the replication rate are set to 40M, but I unlock them when I need a full resync and nothing is running with the drbdsetup {device} syncer [-a {dev_minor}] [-r {rate}] command.

----- Mail original -----

De: "Eduardo Diaz - Gmail" <ediazrod [at] gmail>
À: "Felix Frank" <ff [at] mpexnet>
Cc: "François Delpierre" <drbd [at] pivert>, drbd-user [at] lists
Envoyé: Samedi 7 Janvier 2012 10:48:44
Objet: Re: [DRBD-user] drbd performance issue on SATA

Hi, please send to the list the final performance :-) too see how drbd
do "the job"...

On Fri, Jan 6, 2012 at 9:51 AM, Felix Frank <ff [at] mpexnet> wrote:
> Hi,
>
> On 01/06/2012 09:46 AM, François Delpierre wrote:
>> you can replicate at 90MB/s in one way,
>
> that's true, but it's advisable to use no more than 30% of your total
> bandwidth for syncing, so that your DRBD write latency won't suffer.
>
> Cheers,
> Felix
> _______________________________________________
> drbd-user mailing list
> drbd-user [at] lists
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