[DRBD-user] drbd storage size

Ivan ivan at c3i.bg
Sat Oct 25 14:12:03 CEST 2014

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.


Hi,

On 10/25/2014 02:38 PM, Cesar Peschiera wrote:
> Hi Meji
>
> In three weeks i will have two Intel NIC X520-QDA1 of 40 Gb/s, according
> to these link:
> http://ark.intel.com/products/68672/Intel-Ethernet-Converged-Network-Adapter-X520-QDA1
>
> http://www.intel.com/content/www/us/en/network-adapters/converged-network-adapters/ethernet-x520-qda1-brief.html
>

At those speeds it would be interesting to test the upcoming 3.18 kernel 
with the bulk network transmission patch [1] ; that should save you a 
bunch of cpu cycles.

[1] http://lwn.net/Articles/615238

ivan


>
> In my Hardware setup also i have a RAID controller H710p of Dell (LSI
> chipset with 1 MB of cache) and with two groups of 4 HDDs SAS 15K RPM,
> each group is  configured in RAID 10, this setup is applied for each
> Server (the HDDs for the OS are in other RAID), obviously i don't have
> much storage compared to yours.
>
> In these Servers i will have running DRBD 8.4.5 version
>
> If you want to know the result of my tests, only let me know.
>
> Best regards
> Cesar
>
> ----- Original Message ----- From: "Meij, Henk" <hmeij at wesleyan.edu>
> To: <drbd-user at lists.linbit.com>
> Sent: Thursday, October 23, 2014 5:10 PM
> Subject: Re: [DRBD-user] drbd storage size
>
>
>> a) it turns out the counter  (8847740/11287100)M goes down, not up,
>> deh, never noticed
>>
>> b) ran plain  rsync across eth0 (public, with switches/routers) and
>> eth1 (nic to nic)
>> eth0 sent 585260755954 bytes  received 10367 bytes  116690412.98
>> bytes/sec
>> eth1 sent 585260755954 bytes  received 10367 bytes  122580535.41
>> bytes/sec
>> so my LSI raid card is behaving and DRBD is slowing the initialization
>> down somehow.
>> Found chapter 15 and will try some suggestions but ideas welcome.
>>
>> c) for grins
>> version: 8.4.5 (api:1/proto:86-101)
>> GIT-hash: 1d360bde0e095d495786eaeb2a1ac76888e4db96 build by
>> mockbuild at Build64R6, 2014-08-17 19:26:04
>> 0: cs:SyncTarget ro:Secondary/Secondary ds:Inconsistent/UpToDate C r-----
>>    ns:0 nr:3601728 dw:3601408 dr:0 al:0 bm:0 lo:4 pe:11 ua:3 ap:0 ep:1
>> wo:f oos:109374215324
>>        [>....................] sync'ed:  0.1% (106810756/106814272)M
>>        finish: 731:23:05 speed: 41,532 (31,868) want: 41,000 K/sec
>>
>> 100TB in 731 hours would  be 30 days. Can I expect large delta data
>> replication to go equally slow using DRDB?
>>
>> -Henk
>>
>>
>>
>> ________________________________________
>> From: drbd-user-bounces at lists.linbit.com
>> [drbd-user-bounces at lists.linbit.com] on behalf of Meij, Henk
>> [hmeij at wesleyan.edu]
>> Sent: Thursday, October 23, 2014 9:57 AM
>> To: Philipp Reisner; drbd-user at lists.linbit.com
>> Subject: Re: [DRBD-user] drbd storage size
>>
>> Thanks for the write up y'll.  I'll have to think about #3 not sure I
>> grasp it fully.
>>
>> Last night I started a 12 TB test and started first initialization for
>> observation (0 is primary).
>> I have node0:eth1 wired directly into node1:eth1 with 10 foot CAT 6
>> cable (MTU=9000)
>> Data from node1 to node0
>> PING 10.10.52.232 (10.10.52.232) 8970(8998) bytes of data.
>> 8978 bytes from 10.10.52.232: icmp_seq=1 ttl=64 time=0.316 ms
>>
>> This morning's progress report from node1:(drbd v8.4.5)
>>
>>        [===>................] sync'ed: 21.7% (8847740/11287100)M
>>        finish: 62:50:50 speed: 40,032 (39,008) want: 68,840 K/sec
>>
>> which confuses me: 8.8M out of 11.3M is 77.8% synced, not? I will let
>> this test finish before I do a dd attempt.
>>
>> iostat reveals %idle cpu 99%+ and little to no %iowait (near 0%),
>> iotop confirms very little IO (<5 K/s), typical data
>> Device:         rrqm/s   wrqm/s     r/s     w/s   rsec/s   wsec/s
>> avgrq-sz avgqu-sz   await  svctm  %util
>> sdb1              0.00   231.00    0.00  156.33     0.00 79194.67
>> 506.58 0.46    2.94   1.49  23.37
>>
>> Something is throttling this IO as 40M/s is about half of what I was
>> hoping for. Will dig some more.
>>
>> -Henk
>>
>> ________________________________________
>> From: drbd-user-bounces at lists.linbit.com
>> [drbd-user-bounces at lists.linbit.com] on behalf of Philipp Reisner
>> [philipp.reisner at linbit.com]
>> Sent: Thursday, October 23, 2014 9:17 AM
>> To: drbd-user at lists.linbit.com
>> Subject: Re: [DRBD-user] drbd storage size
>>
>> Am Donnerstag, 23. Oktober 2014, 08:55:03 schrieb Digimer:
>>> On 23/10/14 04:00 AM, Philipp Reisner wrote:
>>> > 2a) Initialize both backend devices to a known state.
>>> >
>>> >      I.e. dd if=/dev/zero of=/dev/sdb1 bs=$((1024*1024)) oflag=direct
>>>
>>> Question;
>>>
>>>    What I've done in the past to speed up initial sync is to create the
>>> DRBD device, pause-sync, then do your 'dd if=/dev/zero ...' trick to
>>> /dev/drbd0. This effectively drives the resync speed to the max possible
>>> and ensures full sync across both nodes. Is this a sane approach?
>>>
>>
>> Yes, sure that is a way to do it. (I have the impression that is
>> something
>> form the drbd-8.3 world.)
>>
>> I do not know from the top of the head if that will be faster than the
>> built-in background resync in drbd-8.4.
>>
>> Best,
>> Phil
>>
>> _______________________________________________
>> drbd-user mailing list
>> drbd-user at lists.linbit.com
>> http://lists.linbit.com/mailman/listinfo/drbd-user
>> _______________________________________________
>> drbd-user mailing list
>> drbd-user at lists.linbit.com
>> http://lists.linbit.com/mailman/listinfo/drbd-user
>> _______________________________________________
>> drbd-user mailing list
>> drbd-user at lists.linbit.com
>> http://lists.linbit.com/mailman/listinfo/drbd-user
>>
>
> _______________________________________________
> drbd-user mailing list
> drbd-user at lists.linbit.com
> http://lists.linbit.com/mailman/listinfo/drbd-user



More information about the drbd-user mailing list