Increasing storage memory on RHEL server
 

Hi All,

I am a new Linux. I ahve following scenario:

We have a application hosted on Linux server and all the data regarding this application is stored on three different mount points on server. Now the storage of this mount point have become full and we need to allocate more storage to this mount points without affecting our application's current data that is residing on this mount points. I need some pre-requisites and point to be taken care before increasing storage on this mount points. I need complete steps on how this can be achieved.

The server is RHEL 6.8

Thank you,
Kunal

To answer such a question we would need to know far more about your storage devices and configuration. Is the storage on a SAN or local disk? Are you using LVM? Are you using RAID, and if so at what level, in hardware or software? What kind of file systems are you using on that storage?
Those answers only get us to the beginning, but they may be enough to start!

Please start by showing the output of these cmds
using CODE tags as described here https://www.linuxquestions.org/quest...do=bbcode#code.

Welcome to LQ

The storage is on SAN also we are using LVM.

Thanks
Kunal

output for lsblk:

NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 1 465G 0 disk
ââsda1 8:1 1 102M 0 part /boot
ââsda2 8:2 1 25G 0 part /usr
ââsda3 8:3 1 15G 0 part /
ââsda4 8:4 1 1K 0 part
ââsda5 8:5 1 15G 0 part /var
ââsda6 8:6 1 2G 0 part [SWAP]
ââsda7 8:7 1 407.9G 0 part /home
sdb 8:16 1 930G 0 disk
ââraidvg-SftpVol (dm-0) 253:0 0 100G 0 lvm
â ââSftp (dm-18) 253:18 0 100G 0 crypt /sftp-jail
ââraidvg-QMvol (dm-1) 253:1 0 80G 0 lvm
â ââQM (dm-12) 253:12 0 80G 0 crypt /databases/QM
ââraidvg-DWvol (dm-2) 253:2 0 70G 0 lvm
â ââDW (dm-13) 253:13 0 70G 0 crypt /databases/DW
ââraidvg-CCMvol (dm-3) 253:3 0 65G 0 lvm
â ââCCM (dm-11) 253:11 0 65G 0 crypt /databases/CCM
ââraidvg-JTSvol (dm-4) 253:4 0 20G 0 lvm
â ââJTS (dm-10) 253:10 0 20G 0 crypt /databases/JTS
ââraidvg-DB2BKVol (dm-5) 253:5 0 230G 0 lvm
â ââDB2BK (dm-17) 253:17 0 230G 0 crypt /db2_online_backups
ââraidvg-Training_Vol (dm-6) 253:6 0 285G 0 lvm
â ââTraining (dm-16) 253:16 0 285G 0 crypt /databases/Training
ââraidvg-RMvol (dm-7) 253:7 0 70G 0 lvm
â ââRM (dm-14) 253:14 0 70G 0 crypt /databases/RM
ââraidvg-DCCvol (dm-8) 253:8 0 10G 0 lvm
ââDCC (dm-15) 253:15 0 10G 0 crypt /databases/DCC

output for df -h :

Filesystem Size Used Avail Use% Mounted on
/dev/sda3 15G 10G 4.0G 72% /
tmpfs 16G 80K 16G 1% /dev/shm
/dev/sda1 99M 69M 26M 73% /boot
/dev/sda7 402G 263G 119G 69% /home
/dev/sda2 25G 2.3G 21G 10% /usr
/dev/sda5 15G 2.2G 12G 16% /var
/dev/mapper/JT 20G 8.6G 11G 47% /databases/JT
/dev/mapper/CC 64G 50G 12G 82% /databases/CC
/dev/mapper/ab 79G 62G 14G 83% /databases/ab
/dev/mapper/D 69G 53G 13G 81% /databases/D
/dev/mapper/R 69G 21G 45G 32% /databases/R
/dev/mapper/Dc 9.8G 4.5G 4.8G 49% /databases/Dc
/dev/mapper/Tr 281G 213G 54G 80% /databases/Tr
/dev/mapper/DB 227G 105G 110G 49% /db2
/dev/mapper/Sftp 99G 6.2G 88G 7% /sftp-


Thanks
Kunal

There are an abundance of topics on the Internet already about how to add storage to an LVM setup, e.g. this one.

Red Hat also provides its subscribers with excellent documentation. As a Red Hat licensee, you should have the necessary logon information somewhere.

You should also check the documentation for your SAN.

Conceptually, LVM allows you to add physical devices (or partitions thereon) to a "physical storage-pool," then to allocate space to "logical volumes" from those pools. (The "logical volumes" are what the operating system sees, and it is not apparent that a logical volume might be spread across many drives.) Once you have added the storage, you simply re-size the filesystem upward so that it can allocate the newly-added space.

You can do all of this without rebooting the system.

In a situation such as yours I have used two methods:
1. export an additional LUN to the server from SAN management, add the new LUN to the volume group using the LVM tools, then expand the file system to the new size. I hate this, but it works even when you have two or three different SAN solutions serving the server.

2. Expand the existing LUN to the new size using the SAN tools, use multipath and tools to recognize the new size in the hardware layer, expand the volume group using the LVM tools, and finally expand the file system to the new size. I have done this LIVE, with the file system mounted, with no problems. Since your hardware and SAN may differ significantly from mine, it may be safer to allow for downtime.

In all cases, it is silly to start any steps without making certain that you have multiple complete and verified backups first. The most simple error could erase all of your data, so be prepared and protected.

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Moved: This thread is more suitable in <Red Hat> and has been moved accordingly to help your thread/question get the exposure it deserves.