Hello, On Fri, 11 Apr 2014 09:48:56 +0800 Punit Dambiwal wrote:
> Hi, > > What is the drawback to run the journals on the RAID1...?? > Did you read what I wrote below? > My plan is 2 SSD RAID1 (then i will create virtual disks for OS as well > as for every OSD).That means one virtual disk of OS and other 24 virtual > disks for journals.... ?? > Assuming your SSD (even though you have 2 since you're using RAID1 you only have the write capacity of one) is a decent Intel DC 3700 400GB, the maximum write speed of that is 460MB/s. Meaning 2 things: a) if your're using 10GbE for networking, you already limited your max throughput to that, instead of the 1GB/s your network could theoretically achieve. b) at that speed your SSD journal can serve about 4 actual OSD disks at full speed. You crippled the performance potential of your storage node immensely. Even with the limitation of the single min-SAS link to the backplane in this storage server (it is a 4x lane, so 24Gb/s total) you would need 4 or 5 dedicated SSDs at the above speed to saturate that link. Of course the bandwidth of that link is theoretical, with 24 disks to server it will be lower in practice. > Please suggest me better way to do this ?? > I already did below. Regards, Christian > > On Wed, Apr 9, 2014 at 4:02 PM, Christian Balzer <ch...@gol.com> wrote: > > > On Wed, 9 Apr 2014 14:59:30 +0800 Punit Dambiwal wrote: > > > > > Hi, > > > > > > I have changed my plan and now i want to use the following supermicro > > > server :- > > > > > > SuperStorage Server 6047R-E1R24L > > > > > > Can any one tell me....is this server is good for the OSD > > > nodes...two ssd on RAID1 (OS & journal) and 24 HDD for OSD (JBOD on > > > the motherboard controller). > > > > > Wrong on so many levels. > > > > Firstly, 2 SSDs (really just one if you're using RAID1 for the journal > > partitions as well) for 24 OSDs. > > The SSD will be a speed bottleneck and also have to handle ALL the > > writes that ever happen to the whole machine (meaning it will wear out > > quickly). > > > > If you want/need SSD journals, a sensible ratio would be 3-4 OSDs per > > journal SSD (partitioned into the respective amount of journals). > > So something like 6 SSDs and 18 HDDs. > > > > Secondly that backplane is connected to the HBA with one mini-SAS link. > > That means at best 4 lanes of 6Gb/s for 24 drives, but it might be just > > one lane, the manual is typical Supermicro quality. =.= > > Another, potentially massive bottleneck. > > > > Also what are your goals in term of throughput, IOPS here? > > If you're planning on getting lots of 24 disk boxes, fine. > > Otherwise you might be better off getting smaller nodes. > > > > Regards, > > > > Christian. > > > > > > > > > > > > > > > > > > On Fri, Apr 4, 2014 at 11:51 AM, Ирек Фасихов <malm...@gmail.com> > > > wrote: > > > > > > > You need to use Dell OpenManage: > > > > > > > > https://linux.dell.com/repo/hardware/. > > > > > > > > > > > > > > > > 2014-04-04 7:26 GMT+04:00 Punit Dambiwal <hypu...@gmail.com>: > > > > > > > >> Hi, > > > >> > > > >> I want to use Dell R515/R510 for the OSD node purpose.... > > > >> > > > >> 1. 2*SSD for OS purpose (Raid 1) > > > >> 2. 10* Segate 3.5' HDDx 3TB for OSD purpose (No RAID...JBOD) > > > >> > > > >> To create JBOD...i created all 10 HDD as raid0....but the problem > > > >> is when i will plug out the HDD from the server and plug-in > > > >> again,i need to import the RAID configuration again to make this > > > >> OSD working.... > > > >> > > > >> Can anyone suggest me good way to do this ?? > > > >> > > > >> Thanks, > > > >> Punit > > > >> > > > >> _______________________________________________ > > > >> ceph-users mailing list > > > >> ceph-users@lists.ceph.com > > > >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > >> > > > >> > > > > > > > > > > > > -- > > > > С уважением, Фасихов Ирек Нургаязович > > > > Моб.: +79229045757 > > > > > > > > > > -- > > Christian Balzer Network/Systems Engineer > > ch...@gol.com Global OnLine Japan/Fusion Communications > > http://www.gol.com/ > > _______________________________________________ > > ceph-users mailing list > > ceph-users@lists.ceph.com > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > -- Christian Balzer Network/Systems Engineer ch...@gol.com Global OnLine Japan/Fusion Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
