>> does 'ceph mds dump' list pool 3 in teh data_pools line? Yes. It lists the desired poolids I wanted to put data in.
---------- Forwarded message ---------- From: hemant surale <[email protected]> Date: Thu, Nov 29, 2012 at 2:59 PM Subject: Re: OSD daemon changes port no To: Sage Weil <[email protected]> I used a little different version of "cephfs" as "cephfs /home/hemant/a set_layout --pool 3 -c 1 -u 4194304 -s 4194304" and "cephfs /home/hemant/b set_layout --pool 5 -c 1 -u 4194304 -s 4194304". Now cmd didnt showed any error but When I put data to dir "a" & "b" ideally it should go to different pool but its not working as of now. Whatever I am doing is it possible (to use 2 dir pointing to 2 different pools for data placement) ? - Hemant Surale. On Tue, Nov 27, 2012 at 10:21 PM, Sage Weil <[email protected]> wrote: > On Tue, 27 Nov 2012, hemant surale wrote: >> I did "mkdir a " "chmod 777 a" . So dir "a" is /home/hemant/a" . >> then I used "mount.ceph 10.72.148.245:/ /ho >> >> root@hemantsec-virtual-machine:/home/hemant# cephfs /home/hemant/a >> set_layout --pool 3 >> Error setting layout: Invalid argument > > does 'ceph mds dump' list pool 3 in teh data_pools line? > > sage > >> >> On Mon, Nov 26, 2012 at 9:56 PM, Sage Weil <[email protected]> wrote: >> > On Mon, 26 Nov 2012, hemant surale wrote: >> >> While I was using "cephfs" following error is observed - >> >> ------------------------------------------------------------------------------------------------ >> >> root@hemantsec-virtual-machine:~# cephfs /mnt/ceph/a --pool 3 >> >> invalid command >> > >> > Try >> > >> > cephfs /mnt/ceph/a set_layout --pool 3 >> > >> > (set_layout is the command) >> > >> > sage >> > >> >> usage: cephfs path command [options]* >> >> Commands: >> >> show_layout -- view the layout information on a file or dir >> >> set_layout -- set the layout on an empty file, >> >> or the default layout on a directory >> >> show_location -- view the location information on a file >> >> Options: >> >> Useful for setting layouts: >> >> --stripe_unit, -u: set the size of each stripe >> >> --stripe_count, -c: set the number of objects to stripe across >> >> --object_size, -s: set the size of the objects to stripe across >> >> --pool, -p: set the pool to use >> >> >> >> Useful for getting location data: >> >> --offset, -l: the offset to retrieve location data for >> >> >> >> ------------------------------------------------------------------------------------------------ >> >> It may be silly question but unable to figure it out. >> >> >> >> :( >> >> >> >> >> >> >> >> >> >> On Wed, Nov 21, 2012 at 8:59 PM, Sage Weil <[email protected]> wrote: >> >> > On Wed, 21 Nov 2012, hemant surale wrote: >> >> >> > Oh I see. Generally speaking, the only way to guarantee separation >> >> >> > is to >> >> >> > put them in different pools and distribute the pools across >> >> >> > different sets >> >> >> > of OSDs. >> >> >> >> >> >> yeah that was correct approach but i found problem doing so from >> >> >> abstract level i.e. when I put file inside mounted dir >> >> >> "/home/hemant/cephfs " ( mounted using "mount.ceph" cmd ) . At that >> >> >> time anyways ceph is going to use default pool data to store files ( >> >> >> here files were striped into different objects and then sent to >> >> >> appropriate osd ) . >> >> >> So how to tell ceph to use different pools in this case ? >> >> >> >> >> >> Goal : separate read and write operations , where read will be done >> >> >> from one group of OSD and write is done to other group of OSD. >> >> > >> >> > First create the other pool, >> >> > >> >> > ceph osd pool create <name> >> >> > >> >> > and then adjust the CRUSH rule to distributed to a different set of OSDs >> >> > for that pool. >> >> > >> >> > To allow cephfs use it, >> >> > >> >> > ceph mds add_data_pool <poolid> >> >> > >> >> > and then: >> >> > >> >> > cephfs /mnt/ceph/foo --pool <poolid> >> >> > >> >> > will set the policy on the directory such that new files beneath that >> >> > point will be stored in a different pool. >> >> > >> >> > Hope that helps! >> >> > sage >> >> > >> >> > >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> - >> >> >> Hemant Surale. >> >> >> >> >> >> >> >> >> On Wed, Nov 21, 2012 at 12:33 PM, Sage Weil <[email protected]> wrote: >> >> >> > On Wed, 21 Nov 2012, hemant surale wrote: >> >> >> >> Its a little confusing question I believe . >> >> >> >> >> >> >> >> Actually there are two files X & Y. When I am reading X from its >> >> >> >> primary .I want to make sure simultaneous writing of Y should go to >> >> >> >> any other OSD except primary OSD for X (from where my current read >> >> >> >> is >> >> >> >> getting served ) . >> >> >> > >> >> >> > Oh I see. Generally speaking, the only way to guarantee separation >> >> >> > is to >> >> >> > put them in different pools and distribute the pools across >> >> >> > different sets >> >> >> > of OSDs. Otherwise, it's all (pseudo)random and you never know. >> >> >> > Usually, >> >> >> > they will be different, particularly as the cluster size increases, >> >> >> > but >> >> >> > sometimes they will be the same. >> >> >> > >> >> >> > sage >> >> >> > >> >> >> > >> >> >> >> >> >> >> >> >> >> >> >> - >> >> >> >> Hemant Sural.e >> >> >> >> >> >> >> >> On Wed, Nov 21, 2012 at 11:50 AM, Sage Weil <[email protected]> >> >> >> >> wrote: >> >> >> >> > On Wed, 21 Nov 2012, hemant surale wrote: >> >> >> >> >> >> and one more thing how can it be possible to read from one >> >> >> >> >> >> osd and >> >> >> >> >> >> then simultaneous write to direct on other osd with less/no >> >> >> >> >> >> traffic? >> >> >> >> >> > >> >> >> >> >> > I'm not sure I understand the question... >> >> >> >> >> >> >> >> >> >> Scenario : >> >> >> >> >> I have written file X.txt on some osd which is primary >> >> >> >> >> for filr >> >> >> >> >> X.txt ( direct write operation using rados cmd) . >> >> >> >> >> Now while read on file X.txt is in progress, Can I make >> >> >> >> >> sure >> >> >> >> >> the simultaneous write request must be directed to other osd >> >> >> >> >> using >> >> >> >> >> crushmaps/other way? >> >> >> >> > >> >> >> >> > Nope. The object location is based on the name. Reads and >> >> >> >> > writes go to >> >> >> >> > the same location so that a single OSD can serialize request. >> >> >> >> > That means, >> >> >> >> > for example, that a read that follows a write returns the >> >> >> >> > just-written >> >> >> >> > data. >> >> >> >> > >> >> >> >> > sage >> >> >> >> > >> >> >> >> > >> >> >> >> >> Goal of task : >> >> >> >> >> Trying to avoid read - write clashes as much as possible >> >> >> >> >> to >> >> >> >> >> achieve faster operations (I/O) . Although CRUSH selects osd for >> >> >> >> >> data >> >> >> >> >> placement based on pseudo random function. is it possible ? >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> - >> >> >> >> >> Hemant Surale. >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> On Tue, Nov 20, 2012 at 10:15 PM, Sage Weil <[email protected]> >> >> >> >> >> wrote: >> >> >> >> >> > On Tue, 20 Nov 2012, hemant surale wrote: >> >> >> >> >> >> Hi Community, >> >> >> >> >> >> I have question about port number used by ceph-osd daemon >> >> >> >> >> >> . I >> >> >> >> >> >> observed traffic (inter -osd communication while data ingest >> >> >> >> >> >> happened) >> >> >> >> >> >> on port 6802 and then after some time when I ingested second >> >> >> >> >> >> file >> >> >> >> >> >> after some delay port no 6804 was used . Is there any >> >> >> >> >> >> specific reason >> >> >> >> >> >> to change port no here? >> >> >> >> >> > >> >> >> >> >> > The ports are dynamic. Daemons bind to a random (6800-6900) >> >> >> >> >> > port on >> >> >> >> >> > startup and communicate on that. They discover each other via >> >> >> >> >> > the >> >> >> >> >> > addresses published in the osdmap when the daemon starts. >> >> >> >> >> > >> >> >> >> >> >> and one more thing how can it be possible to read from one >> >> >> >> >> >> osd and >> >> >> >> >> >> then simultaneous write to direct on other osd with less/no >> >> >> >> >> >> traffic? >> >> >> >> >> > >> >> >> >> >> > I'm not sure I understand the question... >> >> >> >> >> > >> >> >> >> >> > sage >> >> >> >> >> -- >> >> >> >> >> To unsubscribe from this list: send the line "unsubscribe >> >> >> >> >> ceph-devel" in >> >> >> >> >> the body of a message to [email protected] >> >> >> >> >> More majordomo info at >> >> >> >> >> http://vger.kernel.org/majordomo-info.html >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
