Solved

Linux device disks

Posted on 2015-02-06
6
188 Views
Last Modified: 2015-03-18
We were just checking a linux server  that currently has a 4 physical disk drives and one of them  failed. The following are outputs for the system.  We dont' know Linux. Could someone explain the outputs. Like for instance: what is md1 and are sdb3 and sda3  the physical disks or partitions of a physical disk.
-----------------------------------------------------------
[root@r101s0u1bak ~]# cat /proc/mdstat
Personalities : [raid1] [raid0]
md5 : active raid0 md3[0] md4[1]
      3802994752 blocks 64k chunks

md1 : active raid1 sdb3[1] sda3[0]
      8008320 blocks [2/2] [UU]

md3 : active raid1 sdb5[1] sda5[0]
      1899493312 blocks [2/2] [UU]

md2 : active raid1 sdc1[1]
      50010176 blocks [2/1] [_U]

md4 : active raid1 sdc2[1]
      1903501568 blocks [2/1] [_U]

md0 : active raid1 sdb2[1] sda2[0]
      45761088 blocks [2/2] [UU]
----------------------------------------------------

[root@r101s0u1bak ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/md0               43G  4.0G   37G  10% /
/dev/md2               47G  625M   44G   2% /usr/bp
/dev/sdb1             236M   18M  206M   8% /mnt/boot_sync
/dev/sda1             236M   18M  206M   8% /boot
tmpfs                 3.9G     0  3.9G   0% /dev/shm
/dev/md5              3.6T  1.6T  2.0T  44% /backups
[root@r101s0u1bak ~]#
0
Comment
Question by:Shen
  • 3
  • 2
6 Comments
 
LVL 84

Assisted Solution

by:ozo
ozo earned 500 total points
ID: 40593602
md5 : active raid0 md3[0] md4[1]
      3802994752 blocks 64k chunks
/dev/md5 is an active, raid0 array  with component devices  /dev/md3 [device 0] and /dev/md4 [device 1]

md1 : active raid1 sdb3[1] sda3[0]
      8008320 blocks [2/2] [UU]
/dev/md1 is an active, raid1 array with component devices /dev/sdb3 [device 1] and  /dev/sda3  [device 0]
out of 2 devices, 2 are in use, and both are Up

md3 : active raid1 sdb5[1] sda5[0]
      1899493312 blocks [2/2] [UU]
/dev/md3 is an active, raid1 array with component devices /dev/sdb5 [device 1] and  /dev/sda5  [device 0]
out of 2 devices, 2 are in use, and both are Up

md2 : active raid1 sdc1[1]
      50010176 blocks [2/1] [_U]
/dev/md2 is an active, raid1 array with component device /dev/sdc1 [device 1]
out of 2 devices, 1 is in in use, device 0 is down and device 1 is up

md4 : active raid1 sdc2[1]
      1903501568 blocks [2/1] [_U]
/dev/md4 is an active, raid1 array with component device /dev/sdc2 [device 1]
out of 2 devices, 1 is in in use, device 0 is down and device 1 is up

md0 : active raid1 sdb2[1] sda2[0]
      45761088 blocks [2/2] [UU]
/dev/md0 is an active, raid1 array with component devices /dev/sdb1 [device 1] and  /dev/sda2  [device 0]
out of 2 devices, 2 are in use, and both are Up

sdx# is partition # on scsi device x
0
 

Author Comment

by:Shen
ID: 40594462
So if I undertand it:
   the raids  names are the dev/md0..4  
  and  dev/sdbx[] , dev/sdax[], dev/sdcx[], dev/mdx[] are partitions of sdb, sda,  sdc, md  physical devices since the machines has 4 physical drives?
0
 

Author Comment

by:Shen
ID: 40594504
Please forget my previous response:

After reading your explanation more:

all the sdbx,sdax,sdcx, mdx are partitions in 2  devices [0] or [1]. Each devices (0,1) is raid 1, so this makes 4 physical drives.
0
Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

 
LVL 84

Accepted Solution

by:
ozo earned 500 total points
ID: 40594584
I would guess that md2 and md4 would normally have a mirror on /dev/sdd#, and that this is the drive that failed.
0
 

Author Closing Comment

by:Shen
ID: 40598144
thanks.  Do you suggest any tools to fix the drive
0
 

Expert Comment

by:Saravanan Palanisamy
ID: 40675066
Use mdadm command utility to replace the failed drive.
0

Featured Post

Comprehensive Backup Solutions for Microsoft

Acronis protects the complete Microsoft technology stack: Windows Server, Windows PC, laptop and Surface data; Microsoft business applications; Microsoft Hyper-V; Azure VMs; Microsoft Windows Server 2016; Microsoft Exchange 2016 and SQL Server 2016.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This is the error message I got (CODE) Error caused by incompatible libmp3lame 3.98-2 with ffmpeg I've googled this error message and found out sometimes it attaches this note "can be treated with downgrade libmp3lame to version 3.97 or 3.98" …
How many times have you wanted to quickly do the same thing to a list but found yourself typing it again and again? I first figured out a small time saver with the up arrow to recall the last command but that can only get you so far if you have a bi…
Learn several ways to interact with files and get file information from the bash shell. ls lists the contents of a directory: Using the -a flag displays hidden files: Using the -l flag formats the output in a long list: The file command gives us mor…
Get a first impression of how PRTG looks and learn how it works.   This video is a short introduction to PRTG, as an initial overview or as a quick start for new PRTG users.

820 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question