ceph中rbd块的使用技巧有哪些

这篇文章将为大家详细讲解有关ceph中rbd块的使用技巧有哪些，小编觉得挺实用的，因此分享给大家做个参考，希望大家阅读完这篇文章后可以有所收获。

1. rbd块的真实大小

由于ceph采用thin provisioning，只有写数据时才会分配相应的块。所以当我们创建一个很大的块时，也是瞬间完成的，因为除了一些元数据外，ceph并没有分配出相应的空间。那么我们创建的rbd块到底有多大呢？以我的环境为例：

[root@osd1 /]# rbd ls myrbdhello.txtrbd1[root@osd1 /]# rbd info myrbd/rbd1rbd image 'rbd1':        size 1024 MB in 256 objects        order 22 (4096 kB objects)        block_name_prefix: rbd_data.13446b8b4567        format: 2        features: layering[root@osd1 /]# rbd diff myrbd/rbd1 | awk '{ SUM += $2 } END { print SUM/1024/1024 " MB" }'14.2812 MB[root@osd1 /]# rbd diff myrbd/rbd1Offset     Length  Type 0          131072  data 4194304    16384   data 130023424  16384   data 260046848  16384   data 390070272  16384   data 520093696  4194304 data 524288000  4194304 data 528482304  2129920 data 650117120  16384   data 780140544  16384   data 910163968  16384   data 1040187392 16384   data 1069547520 4194304 data

2. rbd format1与rbd fromat2

rbd format1:

[root@osd1 /]# rbd create myrbd/rbd1 -s 8[root@osd1 /]# rbd info myrbd/rbd1rbd image 'rbd1':        size 8192 kB in 2 objects        order 22 (4096 kB objects)        block_name_prefix: rb.0.13fb.6b8b4567        format: 1[root@osd1 /]# rados ls -p myrbdrbd_directoryrbd1.rbd[root@osd1 /]# rbd map myrbd/rbd1[root@osd1 /]# rbd showmappedid pool  image snap device    0  myrbd rbd1  -    /dev/rbd0 [root@osd1 /]# dd if=/dev/zero of=/dev/rbd0 dd: writing to `/dev/rbd0': No space left on device16385+0 records in16384+0 records out8388608 bytes (8.4 MB) copied, 2.25155 s, 3.7 MB/s[root@osd1 /]# rados ls -p myrbdrbd_directoryrbd1.rbdrb.0.13fb.6b8b4567.000000000001rb.0.13fb.6b8b4567.000000000000

1. $image_name.rbd : 包含了这个块的id (rb.0.13fb.6b8b4567)

2. $rbd_id.$fragment : 数据块
   

3. rbd_directory :当前pool中rbd块的列表

rbd format2

[root@osd1 /]# rbd create myrbd/rbd1 -s 8 --image-format=2[root@osd1 /]# rbd info myrbd/rbd1rbd image 'rbd1':        size 8192 kB in 2 objects        order 22 (4096 kB objects)        block_name_prefix: rbd_data.13436b8b4567        format: 2        features: layering[root@osd1 /]# rados ls -p myrbdrbd_directoryrbd_header.13436b8b4567rbd_id.rbd1[root@osd1 /]# rbd map myrbd/rbd1[root@osd1 /]# rbd showmappedid pool  image snap device    0  myrbd rbd1  -    /dev/rbd0 [root@osd1 /]# dd if=/dev/zero of=/dev/rbd0dd: writing to `/dev/rbd0': No space left on device16385+0 records in16384+0 records out8388608 bytes (8.4 MB) copied, 2.14407 s, 3.9 MB/s[root@osd1 /]# rados ls -p myrbdrbd_directoryrbd_data.13436b8b4567.0000000000000000rbd_data.13436b8b4567.0000000000000001rbd_header.13436b8b4567rbd_id.rbd1

1. rbd_data.$rbd_id.$fragment :数据块

2. rbd_directory : 当前pool中rbd块的列表

3. rbd_header.$rbd_id : rbd块的元数据
   

4. rbd_id.$image_name : 包含了这个块的id ( 13436b8b4567 )

3. Ceph Primary Affinity

[root@mon0 yum.repos.d]# ceph --admin-daemon /var/run/ceph/ceph-mon.*.asok config show | grep 'primary_affinity'  "mon_osd_allow_primary_affinity": "false",#在ceph.conf中加入primary affinitymon osd allow primary affinity = true[root@mon0 yum.repos.d]# ceph pg dump | grep active+clean | egrep "\[0," | wc -ldumped all in format plain109[root@mon0 yum.repos.d]# ceph pg dump | grep active+clean | egrep ",0\]" | wc -ldumped all in format plain123# ceph osd primary-affinity osd.0 0.5set osd.0 primary-affinity to 0.5 (8327682)# ceph pg dump | grep active+clean | egrep "\[0," | wc -l48# ceph pg dump | grep active+clean | egrep ",0\]" | wc -l132# ceph osd primary-affinity osd.0 0set osd.0 primary-affinity to 0 (802)# ceph pg dump | grep active+clean | egrep "\[0," | wc -l0# ceph pg dump | grep active+clean | egrep ",0\]" | wc -l180

4. 升级ceph

29号ceph放出了0.87 giant版本，我们第一时间进行了升级。升级过程非常简单，只需修改一处ceph.repo，然后yum update ceph就可以了。升级完成后重启各种服务。ceph.repo如下：

[root@mon0 software]# cat /etc/yum.repos.d/ceph.repo[Ceph]name=Ceph packages for $basearchgpgkey=https://ceph.com/git/?p=ceph.git;a=blob_plain;f=keys/release.ascenabled=1baseurl=http://ceph.com/rpm-giant/el6/$basearchpriority=1gpgcheck=1type=rpm-md[ceph-source]name=Ceph source packagesgpgkey=https://ceph.com/git/?p=ceph.git;a=blob_plain;f=keys/release.ascenabled=1baseurl=http://ceph.com/rpm-giant/el6/SRPMSpriority=1gpgcheck=1type=rpm-md[Ceph-noarch]name=Ceph noarch packagesgpgkey=https://ceph.com/git/?p=ceph.git;a=blob_plain;f=keys/release.ascenabled=1baseurl=http://ceph.com/rpm-giant/el6/noarchpriority=1gpgcheck=1type=rpm-m

5. ceph admin socket

利用ceph admin socket可以获得ceph的在线参数，对于验证与调试很有帮助。

$ ceph --admin-daemon /path/to/your/ceph/socket[root@osd2 ~]# ceph --admin-daemon /var/run/ceph/ceph-osd.4.asok help{ "config diff": "dump diff of current config and default config",  "config get": "config get : get the config value",  "config set": "config set   [ ...]: set a config variable",  "config show": "dump current config settings",  "dump_blacklist": "dump blacklisted clients and times",  "dump_historic_ops": "show slowest recent ops",  "dump_op_pq_state": "dump op priority queue state",  "dump_ops_in_flight": "show the ops currently in flight",  "dump_reservations": "show recovery reservations",  "dump_watchers": "show clients which have active watches, and on which objects",  "flush_journal": "flush the journal to permanent store",  "get_command_descriptions": "list available commands",  "getomap": "output entire object map",  "git_version": "get git sha1",  "help": "list available commands",  "injectdataerr": "inject data error into omap",  "injectmdataerr": "inject metadata error",  "log dump": "dump recent log entries to log file",  "log flush": "flush log entries to log file",  "log reopen": "reopen log file",  "objecter_requests": "show in-progress osd requests",  "perf dump": "dump perfcounters value",  "perf schema": "dump perfcounters schema",  "rmomapkey": "remove omap key",  "setomapheader": "set omap header",  "setomapval": "set omap key",  "status": "high-level status of OSD",  "truncobj": "truncate object to length",  "version": "get ceph version"}

获取journal相关的参数设置：

[root@osd2 ~]# ceph --admin-daemon /var/run/ceph/ceph-mon.osd2.asok config show | grep journal  "debug_journaler": "0\/5",  "debug_journal": "1\/3",  "journaler_allow_split_entries": "true",  "journaler_write_head_interval": "15",  "journaler_prefetch_periods": "10",  "journaler_prezero_periods": "5",  "journaler_batch_interval": "0.001",  "journaler_batch_max": "0",  "mds_kill_journal_at": "0",  "mds_kill_journal_expire_at": "0",  "mds_kill_journal_replay_at": "0",  "mds_journal_format": "1",  "osd_journal": "\/var\/lib\/ceph\/osd\/ceph-osd2\/journal",  "osd_journal_size": "5120",  "filestore_fsync_flushes_journal_data": "false",  "filestore_journal_parallel": "false",  "filestore_journal_writeahead": "false",  "filestore_journal_trailing": "false",  "journal_dio": "true",  "journal_aio": "true",  "journal_force_aio": "false",  "journal_max_corrupt_search": "10485760",  "journal_block_align": "true",  "journal_write_header_frequency": "0",  "journal_max_write_bytes": "10485760",  "journal_max_write_entries": "100",  "journal_queue_max_ops": "300",  "journal_queue_max_bytes": "33554432",  "journal_align_min_size": "65536",  "journal_replay_from": "0",  "journal_zero_on_create": "false",  "journal_ignore_corruption": "false",

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