Storage

The Basics NFS vs iscsi NFS can handle simultaniously writing from several clients. NFS is a filesystem , iscsi is a block storage. iscsi performance are same with NFS. iscsi will appear as disk to the OS, not the case for NFS. Concurrent access to a block device like iSCSI is not possible with standard file systems. You’ll need a shared disk filesystem (like GFS or OCSFS) to allow this, but in most cases the easiest solution would be to just use a network share (via SMB/CIFS or NFS) if this is sufficient for your application.

Server Side First Install samba and samba-client (for debug + test) /etc/samba/smb.conf 1[home] 2Workgroup=WORKGROUP (le grp par defaul sur windows) 3Hosts allow = ... 4[shared] 5browseable = yes 6path = /shared 7valid users = user01, @un_group_au_choix 8writable = yes 9passdb backend = tdbsam #passwords are stored in the /var/lib/samba/private/passdb.tdb file. Test samba config testparm /usr/bin/testparm -s /etc/samba/smb.conf smbclient -L \192.168.56.102 -U test : list all samba shares available smbclient //192.168.56.102/sharedrepo -U test : connect to the share pdbedit -L : list user smb (better than smbclient)

SSHFS SSHFS mounts a remote filesystem on your local filesystem through an SSH connection, all with user rights. The advantage is being able to manipulate remote data with any file manager (Nautilus, Konqueror, ROX, or even the command line). - Prerequisites: administrator rights, ethernet connection, installation of FUSE and the SSHFS package. - SSHFS users must belong to the `fuse` group. Note: FUSE allows a user to mount a filesystem themselves. Normally, mounting a filesystem requires being an administrator, or having it pre-approved in /etc/fstab with hard-coded information.

Find old files 1find . -type f -mtime +150 -exec ls -lrt {} \; | more 2find . -maxdepth 1 -name "*.log" -mtime +10 -exec ls -lrt {} \; 3find . -mtime +150 -exec rm -f {} \; The find loop is cheaper than a shell loop (for ...). You can make it even more efficient by batching the rm calls: 1find . -type f -print -exec rm -- "{}" + # note the "+" instead of the usual "\;" See which directories use the most space 1du -max . # list all the FS sub-directories (-x avoids filesystems other than the requested one, "." = search from where you are) 2du -sh * # show the total without listing the sub-directories (h = human readable) 3du -max . | sort -n | tail -30 # the 30 largest files/directories 4du -ks * | sort -n # size in kilobytes of all files and directories, where you are 5du -hsc * | sort -h # from smallest to largest 6ls -lrS # list files by size (in bytes) - note: ls -l does not give the true value contained in a directory 7du -ch /dir/ # size of the directories contained in /dir/ (with suffix) then the total Reduce / Truncate a file 1perl -e 'truncate "wanted_file", 100000' 2truncate -s 0 /ftpusers/ftp.upload.log File deleted but space still held by a process 1lsof +aL1 # "+L1" selects open files that have been "unlinked" (deleted but still open) 2lsof -nP | grep '(deleted)' 3find /proc/*/fd -type f -links 0 -exec ls -lrt {} \; # [SunOS] There are two solutions:

Rsync The classic formula 1rsync -arv --info=progress2 photo backup_photo a = archive — preserves permissions (owner, group), times, symbolic links and devices. r = recursive — copies directories and sub-directories. v = verbose — prints what is being copied. Examples 1rsync -apvz --stats --update --exclude gsast/olap_cubes --exclude gsast/param user@server-src:/export/ user@server-dest:/home/ 2rsync -av -e ssh root@192.168.1.10:/backup/DUMP/* . 3rsync -azp --stats root@oracle-src:/ec/sw/oracle/client/product/12.2.0.1/network/mesg/ ~/mesg/ 4rsync -azp /home/user/mesg/ root@oracle-dest.example.com:/ec/sw/oracle/client/product/12.2.0.1/network/mesg/ 5 6ssh root@oracle-dest.example.com "ls -lrt /ec/sw/oracle/client/product/12.2.0.1/network/mesg/" 7ssh root@oracle-dest.example.com "chown oracle:dc_dba /ec/sw/oracle/client/product/12.2.0.1/network/mesg/*" 8 9rsync -aS --delete --rsh /export/home backup-host:/export/save Propagate deletions to the backup If you delete files in the source directory, rsync does not propagate the deletion to the backup directory unless you add the --delete option.

General concern If you want to move VMs to an another Storage Domain, you need to copy the template from it as well! Remove a disk: 1# IF RHV does not use anymore disk those should appear empty in lsblk: 2lsblk -a 3sdf 8:80 0 4T 0 disk 4└─36001405893b456536be4d67a7f6716e3 253:38 0 4T 0 mpath 5sdg 8:96 0 4T 0 disk 6└─36001405893b456536be4d67a7f6716e3 253:38 0 4T 0 mpath 7sdh 8:112 0 4T 0 disk 8└─36001405893b456536be4d67a7f6716e3 253:38 0 4T 0 mpath 9sdi 8:128 0 0 disk 10└─360014052ab23b1cee074fe38059d7c94 253:39 0 100G 0 mpath 11sdj 8:144 0 0 disk 12└─360014052ab23b1cee074fe38059d7c94 253:39 0 100G 0 mpath 13sdk 8:160 0 0 disk 14└─360014052ab23b1cee074fe38059d7c94 253:39 0 100G 0 mpath 15 16# find all disks from LUN ID 17LUN_ID="360014054ce7e566a01d44c1a4758b092" 18list_disk=$(dmsetup deps -o devname ${LUN_ID}| cut -f 2 |cut -c 3- |tr -d "()" | tr " " "\n") 19echo ${list_disk} 20 21# Remove from multipath 22multipath -f "${LUN_ID}" 23 24# remove disk 25for i in ${list_disk}; do echo ${i}; blockdev --flushbufs /dev/${i}; echo 1 > /sys/block/${i}/device/delete; done 26 27# You can which disk link with which LUN on CEPH side 28ls -l /dev/disk/by-* NFS for OLVM/oVirt Since oVirt need a shared stockage, we can create a local NFS to bypass this point if no Storage bay.

Tar - “tape archiver” Preserve files permissions and ownership. The Basics 1# Archive 2tar cvf my_archive.tar <file1> <file2> </dir/folder/> 3 4## Archive and compress with zstd everything in the current dir and push to /target/dir 5tar -I zstd -vcf archive.tar.zstd -C /target/dir . 6 7# Extract 8tar xvf my_archive.tar 9 10# Extract and push to target dir 11tar -zxvf new.tar.gz -C /target/dir Other useful options • t : list archive’s content. • T : archive list given by a file. • P : preserve absolute path (useful for backing up /etc). • X : exclude. • z : gunzip compression. • j : bzip2 compression. • J : lzma compression.

S3cmd command S3cmd is a tool to handle blockstorage S3 type. Install the command 1# Ubuntu install 2sudo apt-get install s3cmd 3 4# Redhat install 5sudo dnf install s3cmd 6 7# or from sources 8wget https://sourceforge.net/projects/s3tools/files/s3cmd/2.2.0/s3cmd-2.2.0.tar.gz 9tar xzf s3cmd-2.2.0.tar.gz 10cd s3cmd-2.2.0 11sudo python3 setup.py install Configure it From Cloud providers (for example DO): Log in to the DigitalOcean Control Panel. Navigate to API > Spaces Access Keys and generate a new key pair.