CephNotes

Some notes about Ceph
Laurent Barbe @SIB

Find the OSD location

Of course, the simplest way is using the command ceph osd tree.

Note that, if an osd is down, you can see "last address" in ceph health detail :

$ ceph health detail
...
osd.37 is down since epoch 16952, last address 172.16.4.68:6804/628

Also, you can use …

LXC 2.0.0 First support for Ceph RBD

FYI, the first RBD support has been added to LXC commands.

Example :

# Install LXC 2.0.0 (ubuntu) :
$ add-apt-repository ppa:ubuntu-lxc/lxc-stable
$ apt-get update
$ apt-get install lxc

# Add a ceph pool for lxc bloc devices :
$ ceph osd pool create lxc 64 64

# To create the container, you only need to …

Downgrade LSI 9207 to P19 firmware

After numerous problems encountered with the P20 firmware on this card model, here are the steps I followed to flash in P19 Version.

Since, no more problems :)

The model of the card is a LSI 9207-8i (SAS2308 controler) with IT FW:

lspci | grep LSI
01:00.0 Serial Attached SCSI …

Get OMAP key/value size

List the total size of all keys for each object on a pool.

object        size_keys(kB)  size_values(kB)  total(kB)  nr_keys  nr_values
meta.log.44   0              1                1          0        10
data_log.78   0              56419            56419      0        406841
meta.log.36   0              1                1          0        10
data_log.71   0              56758            56758 …

The kernel 4.1 is out

This kernel version support all features for Hammer, in particular straw v2.

https://www.kernel.org/

The main changes in this version:

rbd: rbd_wq comment is obsolete
libceph: announce support for straw2 buckets
crush: straw2 bucket type with an efficient 64-bit crush_ln()
crush: ensuring at most num-rep osds …