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17.68 15.35 0.00 54.2703:40:01 PM All 17.22 0.00 13.42 15.50 0 .53.8603:50:01 pm All 19.16 0.00 10.48 14.86 0.00 55.4904:00:01 PM All 11.95 0.00 14.80 15.52) 0.00 57.73Iotop a bit, the JBD2 process consumes a lot of IO processing, searching for the next, about Jbd2,jbd2 is part of the Ext4 file system. EXT4 file System This bug,bug principle is roughly that
:00 [crypto/0] 44? S 0:00 [kthrotld/0] 45? S 0:00 [PCIEHPD] 47? S 0:00 [kpsmoused] 48? S 0:00 [Usbhid_resumer] 49? S 0:00 [Deferwq] 81? S 0:00 [Kdmremove] 82? S 0:00 [kstriped] 113? S 0:00 [Ttm_swap] 242? S 0:00 [scsi_eh_0] 246? S 0:00 [scsi_eh_1] 266? S 1:08 [mpt_poll_0] 267? S 0:00 [mpt/0] 268? S 0:00 [scsi_eh_2] 363? S 0:12 [flush-8:0] 416? S 0:02 [jbd
KSOFTIRQD/3 33? 00:00:00 kworker/3:0h 34? 00:00:00 Khelper 35? 00:00:00 KDEVTMPFS 36? 00:00:00 Netns 37? 00:00:00 Writeback 38? 00:00:00 Kintegrityd 39? 00:00:00 Bioset 40? 00:00:00 kworker/u9:0 41? 00:00:00 KBLOCKD 42? 00:00:00 ATA_SFF 43? 00:00:00 KHUBD 44? 00:00:00 MD 45? 00:00:00 DEVFREQ_WQ 46? 00:00:01 kworker/0:1 48? 00:00:00 KHUNGTASKD 49? 00:00:00 kswapd0 50? 00:00:00
, 0K shrd, 272K buff, 2524K cachedcpu:24.6% usr 0.2% sys 0.0% nic 74.8% idle 0.2% io 0. 0% IRQ 0.0% sirqload average:0.82 0.79 0.48 2/61 1471 PID PPID USER STAT VSZ%vsz CPU%cpu COMMAND 1412 1399 0 R 5004 0.4 0 24.6/cam_previewfb0v3 1471 1399 0 R 2392 0.2 3 0.2 top-d1 1399 1 0 s 2392 0.2 1 0.0-/bin/sh 1 0 0 S 2388 0.2 3 0.0 init 2 0 SW 0 0.0 1 0.0 [kworker/1:1] 372 2 0 SW 0 0.0 0 0.0 [KHUBD] 1356 2 0 SW 0 0.0 0 0.0 [ Kworker/0:3] 6 2 0 SW 0 0.0 2 0.0 [kworker/u:0] 2 0 SW 0 0.0 2 0
, I used iotop to find an I/O criminal, jbd2. OverviewThe journaling block device (jbd) provides a filesystem-independent interface for filesystem journaling. ext3, ext4 and ocfs2 are known to use jbd. ocfs2 starting from Linux 2.6.28 and ext4 use a fork of jbd called jbd2. It is known that its main function is to write logs to the file system. So I/O pressure must be too high due to too frequent operat
Fixed the ext4 bug. A kernel bug was reported during production: MySQL used the entire Kernel panic during reset master. DBAs are very enthusiastic to help find the re-step: it is a mine-like file, as long as it is open, then fdatasync, Kernel panic. The position of the panic code is j_assert (Journal-> j_running_transaction!) in jbd2_journal_commit_transaction! = NULL); however, why does jbd2 commit transactions when running_transaction is not trigge
[Email protected] ~]# umount/drbd/Umount:/drbd:device is busy.(In some cases useful info about processes, use the device are found by lsof (8) or fuser (1))Solution One:First, find the process and command to use this file, the specific operation code[Email protected] ~]# lsof |grep "/DRBD"JBD2/DRBD 8219 root CWD DIR 253,0 4096 2/JBD2/DRBD 8219 root RTD DIR 253,0 4096 2/
A few days ago encountered Jbd2 process to occupy a large amount of disk Io, with iotop to see the situation is generally as follows:System version: Centos6.5-64bit650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/6F/B1/wKiom1WlNR2hcwJIAAKvAWzrg_U127.jpg "title=" Iotop.png "alt=" Wkiom1wlnr2hcwjiaakvawzrg_u127.jpg "/>650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/6F/AE/wKioL1WlNwawFemjAAI7czGLBYQ543.jpg "title=" Iotop1.png "alt="
is only a measure of the rush (non-idle time) and is not significant for virtual devices that are backed by multiple disks later. These devices can be better understood by applying a load: IOPS (r/s + w/s) and throughput (rkb/s + wkb/s).IotopTop tool that contains disk I/O.Batch mode (-B) provides scrolling output. The following demo shows only the I/O process (-O), output once every 5 seconds (-D5):[Email protected] ~]# IOTOP-BOD5Total DISK read:0.00 b/S | Total DISK write:8.76 k/sactual DISK
10 '; Do Ps-eo State,pid,cmd | grep "^d"; echo "----"; Sleep 5; Done d 248 [jbd2/dm-0-8] D 16528 bonnie++-n 0-u 0-r 239-s 478-f-b-d/tmp----d [Kdmflush] D 16528 bonnie++-N 0 -U 0-r 239-s 478-f-b-d/tmp----# or: While true; do date; PS AUXF | awk ' {if ($8== "D") print $;} '; Sleep 1; Done Tue 20:03:54 CLT (Root 302 0.0 0.0) 0 0? D May22 2:58 \_ [Kdmflush] root 321 0.0 0.0 0 0? D May22 4:11 \_ [jbd2
hardware reason, we can try to move the read/write operation to another disk, and then look at the effect:3. The last words: a different path In fact, in addition to using the above professional tools to locate this problem, we can directly use the Process status to find the relevant process. We know that the process has the following statuses: D uninterruptible sleep (usually IO) R running or runnable (on run queue) S interruptible sleep (waiting for an event to complete) T stopped, eithe
/modules/2.6.32-642.el6.x86_64/kernel/fs/jbd2/jbd2.ko Insmod/lib/modules/2.6.32-642.el6.x86_64/kernel /fs/ext4/ext4.ko#通过depmod生成的配置文件查询[[email protected] ~]# grep ' \#当然如果此模块已经被加载, you can also view dependencies by Lsmod[Email protected] ~]# Lsmod | grep ' \View module specific parametersModprobe-c#查看isofs的具体参数[Email protected] ~]# Modprobe-c | grep ' \Parse: There are no additional kernel parameters, but
Tags: jdb2 centosA few days ago encountered Jbd2 process to occupy a large amount of disk Io, with iotop to see the situation is generally as follows:System version: Centos6.5-64bit650) this.width=650; "src=" Http://image.lxway.com/upload/6/75/67554ca6f1ecf4c1667509de64c19089_thumb.jpg "alt=" JDB2 results in high disk IO usage "title=" JDB2 results in high disk IO usage "style=" border:0px;vertical-align:middle;height:auto; "/>650) this.width=650; "sr
information. PS: It is recommended that our servers enable this option CPU load value is high, indicating that there are too many threads in the running state and D state. The thread waits for the resource to go to sleep, goes into the D state (that is, disk sleep, deep sleep), the thread into the D state cannot be interrupted, and they sleep until the waiting resource is released and wakes them up. (the general principle is that these threads wait for what resources, such as a
the relevant process.We know that the process has the following States:Sleepsleepfor2.6. XX kernel) X dead (should never be seen) Z Defunct ("zombie") process, terminated but not reaped by its parent.Where the status is D is usually caused by the wait IO to cause so-called "non-disruptive sleep", we can start from this point and then step by bit to locate the problem: forXinch`seq Ten`; Do PS-eo State,pid,cmd |grep "^d";Echo "----";Sleep 5; DoneD248[jbd2
the relevant process.We know that the process has the following States: PROCESS State CODES D uninterruptible sleep (usually IO) R running or runnable (on run queue) S Interruptib Le Sleep (Waiting for the event to complete) T stopped, either by a job control signal or because it's being traced. W Paging (not valid since the 2.6.xx kernel) X dead (should never is seen) Z defunct ("zombie") process, Termin Ated but not reaped by its parent. The where the status is D is usually caused by t
(1-41610, default 1 ): press Enter and press Enter. [Enter] [plain] Last cylinder or + size or + sizeM or + sizeK (1-41610, default 41610 ): enter w to write data and exit [plain] Command (m for help): w www.2cto.com 3. Before formatting a virtual hard disk partition and formatting it to ext4, you must first check the system Whether to load the ext4 module [plain] [root @ localhost ~] # Lsmod | if grep ext4 is not loaded, manually load it (there is an ext4 module in centos5.x, but it needs to b
What this section says: using the Linux kernel module actual combat-compile an NTFS kernel module, implement Linux mount NTFS file system and implement read and write functionsKernel module operationKernel (module) management commands:The function of a module: A program that encapsulates a specific function. For example, Oki Bao. All phones can be flushed.The target path of the kernel module is stored:[Email protected]]# ls3.10.0-229.el7.x86_64 4.2.4[[Email protected]]# cd/lib/modules/4.2.4/ke
Error: modinfo: cocould not find module snd_ens1371 Error: modinfo: cocould not find module snd_rawmidi Error: modinfo: cocould not find module snd_ac97_codec Error: modinfo: cocould not find module ac97_bus Error: modinfo: cocould not find module snd_seq Error: modinfo: cocould not find module snd_seq_device Error: modinfo: cocould not find module snd_pcm Error: modinfo: cocould not find module snd_timer Error: modinfo: cocould not find module SND Error: modinfo: cocould not find module soundc
S 2.0 6.8. 89 vs_exe3 iotop: 3.1 features Is a top tool used to monitor the disk I/O usage of each thread, Note: You must install this command by yourself (yum install iotop)3.2 command output Total disk read: 50.23 M/s | Total disk write: 34.25 K/s Tid prio user disk read disk write swapin io> COMMAND 61524 be/4 root 47.65 M/s 0.00 B/s 0.00% 37.83%./relay_server 61539 be/4 root 121.77 K/s 0.00 B/s 0.00% 26.73%./relay_server 61544 be/4 root 700.15 K/s 0.00 B/s 0.00% 24.89%./relay_server 61543 b
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