XFS is a highly scalable filesystem. It can scale to 8 EiB, with online resizing; the filesystem can grow as long as there is unallocated space and it can span multiple partitions and devices. XFS is one of the fastest filesystems around, especially in combination with RAID volumes. But, this comes with a cost: you’ll […]
ioping: command not found
The ioping command generates a report of device I/O latency in real-time. It will continuously “ping” the specified device with requests and print information about each request at the command-line. By default, this information tracks how long it took an I/O request to finish. Aside from specifying a device to test, you can also specify […]
iostat: command not found
The iostat utility generates reports on CPU and device usage. For storage, it provides input and output statistics for block devices and partitions. Using the -d option to specify device information only, the iostat command lists the following statistics for each storage device: Transfers (I/O requests) per second (tps). Number of blocks read per second […]
df: command not found
Sometimes you need to see how much disk space is available on an individual device. The df command allows you to easily see what’s happening on all the mounted disks: $ df -h Filesystem Size Used Avail Capacity iused ifree %iused Mounted on /dev/disk1s5s1 113Gi 15Gi 37Gi 29% 577263 385625880 0% / devfs 189Ki 189Ki […]
du: command not found
With the df command, it is easy to see when a disk is running out of space. The next problem for the system administrator is to know what to do when that happens. Another useful command to help you out is the du command. The du command shows the disk usage for a specific directory […]
ulimit: command not found
The ulimit command allows users to view or reduce their limits for the current shell. Only the root user can increase restrictions above the specified hard limit The limits set also apply to any child process of the shell. The shell man page provides more information about usage of the ulimit command, an excerpt from […]
file: command not found
A file name is a string of characters that identify a file. By using the right combination of characters in file names, you can ensure that the files are unique and easy to recognize. On an ext4 file system, a file name may be up to 255 bytes long and contain any byte except NULL […]
dumpe2fs: command not found
The dumpe2fs command is used to dump ext2, ext3, and ext4 file system information. It prints the superblock and block group information for the selected device. This can be useful when troubleshooting a faulty file system. Syntax The syntax of the dumpe2fs command is: # dumpe2fs [options] {device/ file system name} dumpe2fs Command Options The […]
tune2fs: command not found
The tune2fs command helps you configure various “tunable” parameters associated with an ext2/3/4 file system. Tunable parameters enable you to remove reserved blocks, alter reserved block count, specify the number of mounts between checks, specify the time interval between checks, and more. You can also use tune2fs to add a journal to an existing ext2 […]
resize2fs: commnd not found
The resize2fs command is used to enlarge or shrink an ext2/3/4 file system on a device. You can enlarge a mounted file system, but you must unmount the file system before you can shrink it. You can specify the desired size of the file system in order to either enlarge or shrink it. If you […]