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Showing posts from July, 2018

Basic Concepts: Linux Disks

Disk Interface IDE (ATA): Bandwidth is 133 Mbps. IOPS is ~100. The interface can connect maximum 2 disks. SCSI: IOPS is ~ 150. It can connects 8 or 16 disks Ultrascsi320 - 320 MB/s Ultrascsi640 - 640 MB/s SATA: Bandwidth is 6 Gbps. IOPS is ~150. It can connects to 8 or 16 disks. SAS: Bandwidth is 6 Gbps. IOPS is ~200. It can connects to 8 or 16 disks. USB: Bandwidth is 480 MB/s. IOPS is vary. Linux Disks Disk (Device) Types Block : Can be accessed randomly. Unit is "block". Character : Can be accessed sequentially. Unit is "character". Disk Files (FHS) Files are under ' /dev/' . Every disk (device) is file on Linux environment. Device ID: Major : Primary device ID. To identify device type for proper drivers. Minor : Secondary device ID. It's the entree of specific device of same type of device. Create new device: # mknode [root@centos] mknode /dev/usbtest b 100 231 [root@centos] ll | grep test brw-r--r--. 1 root root 100, 231 Jul 1 11:02 us