-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 #1 `readlink /var/lib/ceph/osd/-/journal` If it returns nothing then it is a file, if it returns something it is a partition.
#2 It appears that the default of ceph-deploy is to create and use a partition (I don't use ceph-deploy, so I can't be authoritative). This makes sense as there is a lot of overhead in a file system and a file and by using a raw partition, it cuts that all out and gives better performance. All writes land at the journal first, then are later flushed to the XFS/EXT4 file system. This helps turn random I/O into 'less'-random I/O. You can see big performance gains by locating the journal on a partition of a quality SSD (there are plenty of threads about "quality" SSD). -----BEGIN PGP SIGNATURE----- Version: Mailvelope v0.13.1 Comment: https://www.mailvelope.com wsFcBAEBCAAQBQJVdw89CRDmVDuy+mK58QAAuWkP/1FqhX1DhZXKOIfMf8Of 6H0Y3Qi+eCWmpcteOZIK+fF3ZXXHsAp2hU+ON8TWjLZXEmPQj49tuJfkQfdj DYO4s1k2Bc5D3PP5UsIM9t76rJuJfBXk7i8816GIvwKgiDDiVnNG4UZut5xW TzpOwpq8vPB3E3cWI/Zg7W4R61D7SbtIzrdu6LVaCatLmHMIM2Aj4Zgdjlqz 1+1t2oy+8NmTr8OqDeZCV+9HdsPWtVkhmcba9CJvT1MYHrXvhMVBKZcso0mb bzS9xxw0FfyX7cDZQUsduP/kR2u6yEj6vyXw2sRGBDAj6Cx6Zc2YcfiDi/cJ hOmN+8nRo4D35O97qFtVGPrcJJjB4titoA/yfTslqzo89omkOCx1ZycYlwzq xvxuxfY+XznwvpEu40AayPY5e1RqIeY9ntRWt3rTScOY/J3xj7BgawA+Y8rp QVoFyzp+/sQBkTuiVivknUYUDpVXpwng2YLVl9hrjhZfAW/orLiIm/ztq2ro HnrCeyMpGICBdptUYk5XBcEfwMStxaUrWO3cU8QkzYnIToh0aOOX7XkpXuMa s/3d8gtMtC1btATHFBzZ/WIOwhOif7kRSXS9fOi/SYEh0164HunDuAb1KjEM tI0dly7JNGPagz3VAsBXaAoxoKXB1wfkdo0I59OmFTDGwoYOLQi5jhQd7csl A7Am =1XtM -----END PGP SIGNATURE----- ---------------- Robert LeBlanc GPG Fingerprint 79A2 9CA4 6CC4 45DD A904 C70E E654 3BB2 FA62 B9F1 On Tue, Jun 9, 2015 at 8:35 AM, Vickey Singh <vickey.singh22...@gmail.com> wrote: > Thanks Michael for your response. > > Could you also please help in understanding > > #1 On my ceph cluster , how can i confirm if journal is on block device > partition or on file ? > > #2 Is it true that by default ceph-deploy creates journal on dedicated > partition and data on another partition if i use the command ceph-deploy > osd create ceph-node1:/dev/sdb > > I want to understand the concept of journals creation in Ceph. Hope you > will help me. > > - vicky > > On Tue, Jun 9, 2015 at 5:28 PM, Michael Kuriger <mk7...@yp.com> wrote: > >> You could mount /dev/sdb to a filesystem, such as /ceph-disk, and then >> do this: >> ceph-deploy osd create ceph-node1:/ceph-disk >> >> Your journal would be a file doing it this way. >> >> >> >> [image: yp] >> >> >> >> Michael Kuriger >> >> Sr. Unix Systems Engineer >> >> * mk7...@yp.com |( 818-649-7235 >> >> From: Vickey Singh <vickey.singh22...@gmail.com> >> Date: Tuesday, June 9, 2015 at 12:21 AM >> To: "ceph-users@lists.ceph.com" <ceph-users@lists.ceph.com> >> Subject: [ceph-users] Beginners ceph journal question >> >> Hello Cephers >> >> Beginners question on Ceph Journals creation. Need answers from experts. >> >> - Is it true that by default ceph-deploy creates journal on dedicated >> partition and data on another partition. It does not creates journal on >> file ?? >> >> ceph-deploy osd create ceph-node1:/dev/sdb >> >> This commands is creating >> data partition : /dev/sdb2 >> Journal Partition : /dev/sdb1 >> >> In ceph-deploy command i have not specified journal partition but still >> it creates a journal on sdb1 ? >> >> - How can i confirm if journal is on block device partition or on file ? >> >> - How can i create journal on a file ? command would be helpful ? >> >> Regards >> Vicky >> > > > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > >
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