Questions[disk-volume](server)

I have cent-os 7 installed on an ssd with capacity 160GB. The Cent-os partitions only consume 20GB in total, such that when I run fdisk -l this is my output:

Disk /dev/sda: 171.8 GB, 171798691840 bytes, 335544320 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000a2b1e

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     1026047      512000   83  Linux
/dev/sda2         1026048    41943039    20458496   8e  Linux LVM

Disk /dev/mapper/centos-swap: 2147 MB, 2147483648 bytes, 4194304 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/mapper/centos-root: 18.8 GB, 18798870528 bytes, 36716544 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

When I try to run pvs I get the following:

  PV         VG     Fmt  Attr PSize  PFree
  /dev/sda2  centos lvm2 a--  19.51g    0

What steps do I need to take in order to get CentOS to recognise the full 160GB physical volume, and then be able to either extend centos-root directly or first create another logical partition (of size 140GB), remove it and then allow centos-root to expand into the that space?

Apologies if my terminology is incorrect, I'm not a Linux expert.

Problem: I need to figure out which volume corresponds to what partition(s) which corresponds to what disk in an extremely efficient script able manor. I know how to correspond which partition corresponds to what disk because the disk id is directly in the results of a simple wmic query. However, the first part of the problem is more difficult. How to correlate which volume belongs to which partitions?

Is there a way, using wmic, PowerShell, cmd prompt, to reverse-engineer which volume maps to which partition(s), that works across all currently supported versions of Windows Server (Windows Server 2008R2 - Windows Server 2016)?

If so how would this query look?

Using diskpart to get information is NOT an option. Although it can be used to script out disk operations, it is terrible to use diskpart as a tool to return information about disk configurations. Diskpart output is NOT parsible.

Am getting the following error while trying to mount a ec2 volume

[ec2-user@ip-172-XX-XX-XX-XX ~]$ sudo mount /dev/xvdf /mnt
mount: /dev/xvdf is write-protected, mounting read-only
mount: unknown filesystem type '(null)'

Also, tried to mount the part as below

[ec2-user@ip-172-XX-XX-XX ~]$ sudo mount /dev/xvdf2 /mnt
    mount: wrong fs type, bad option, bad superblock on /dev/xvdf2,
       missing codepage or helper program, or other error

       In some cases useful info is found in syslog - try
       dmesg | tail or so.

I've run into an issue with my KVM host which runs VMs on a LVM volume. As of last night the logical volumes are no longer seen as such (I can't create snapshots of them even though I have been for months now).

Running any scans all result in nothing being found:

[root@apollo ~]# pvscan
No matching physical volumes found

[root@apollo ~]# vgscan
Reading all physical volumes.  This may take a while...
No volume groups found

root@apollo ~]# lvscan
No volume groups found

If I try restoring the VG conf backup from /etc/lvm/backups/vg0 I get the following error:

[root@apollo ~]# vgcfgrestore -f /etc/lvm/backup/vg0 vg0
Couldn't find device with uuid 20zG25-H8MU-UQPf-u0hD-NftW-ngsC-mG63dt.
Cannot restore Volume Group vg0 with 1 PVs marked as missing.
Restore failed.

/etc/lvm/backups/vg0 has the following for the physical volume:

physical_volumes {

            pv0 {
                    id = "20zG25-H8MU-UQPf-u0hD-NftW-ngsC-mG63dt"
                    device = "/dev/sda5"    # Hint only

                    status = ["ALLOCATABLE"]
                    flags = []
                    dev_size = 4292870143   # 1.99902 Terabytes
                    pe_start = 384
                    pe_count = 524031       # 1.99902 Terabytes
            }
}

fdisk -l /dev/sda shows the following:

[root@apollo ~]# fdisk -l /dev/sda

Disk /dev/sda: 6000.1 GB, 6000069312512 bytes
64 heads, 32 sectors/track, 5722112 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000188b7

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               2       32768    33553408   82  Linux swap / Solaris
/dev/sda2           32769       33280      524288   83  Linux
/dev/sda3           33281     1081856  1073741824   83  Linux
/dev/sda4         1081857     3177984  2146435072   85  Linux extended
/dev/sda5         1081857     3177984  2146435071+  8e  Linux LVM

The server is running a 4 disk HW RAID10 which seems perfectly healthy according to megacli and smartd.

The only odd message in /var/log/messages is the following which shows up every couple of hours:

Jun 10 09:41:57 apollo udevd[527]: failed to create queue file: No space left on device

Output of df -h

[root@apollo ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda3            1016G  119G  847G  13% /
/dev/sda2             508M   67M  416M  14% /boot

Does anyone have any ideas what to do next? The VMs are all running fine at the moment apart from not being able to snapshot them.

Updated with extra info It's not a lack of inodes:

[root@apollo ~]# df -i
Filesystem            Inodes   IUsed   IFree IUse% Mounted on
/dev/sda3            67108864   48066 67060798    1% /
/dev/sda2              32768      47   32721    1% /boot

pvs, vgs & lvs either output nothing or "No volume groups found".

In my Windows EC2 instance I have 3 drive: C, D, and E.

• C: 30 GB
• D: 1 GB
• E: 1 GB

In my AWS console, I have the following volumes:

• vol-e0059988 (1 GB)
• vol-ec059984 (1 GB)
• vol-ea059982 (30 GB)

How do I know which volume my D and E drive are attached to?