从 Red Hat Enterprise Linux 6.4 开始，ext4 和 XFS 文件系统都完全支持 discard。 要在设备上启用 discard 命令，请使用 mount 命令的 discard 选项。 例如：要将 /dev/sda2 挂载到启用了 discard 的 /mnt 中，请使用：

Using the System Security Services Daemon (SSSD) provides multiple benefits regarding user identity retrieval and user authentication. SSSD optionally keeps a cache of user identities and credentials retrieved from remote providers.

Solid-state disks (SSD) are storage devices that use NAND flash chips to persistently store data. This sets them apart from previous generations of disks, which store data in rotating, magnetic platters.

2020年6月23日 · Both drive technologies store the operating system, application programs, and your data so that they can be moved into main memory (RAM) for use. The functional advantages of SSD over HDD are twofold, and both are due to the solid-state nature of the SSD. First, SSDs have no moving parts to wear out or break.

NVMe SSDs have been supported since RHEL 6.5. With the introduction of kernel 3.10 in RHEL 7, support for booting from NVMe was added. RHEL 7.1 becomes even more capable with hot plug features that were added in by Red Hat.

2018年5月22日 · rhel7支持固态硬盘，并能够针对ssd特性做出优化，例如在i/o调度器中使用适合ssd的算法，以及管理固态硬盘的写入放大等问题。 I/O堆栈和限制 输入/输出（I/O）是计算机系统中数据交换的过程，I/O堆栈是指与数据读写 . . .

2020年10月28日 · Recent improvements in SSD firmware have made the need for the applications writing to SSDs less stringent to use DISCARD/TRIM. There are, however, some cases in which you may need to have the filesystem inform the drive of …

2022年1月21日 · 如果之前SSD是没有进行格式化的，就没有文件系统，在进行mount挂载的时候会出现： mount: /dev/nvme2n1 is write-protected, mounting read-only mount: unknown filesystem type '(null)' 所以在没有文件系统的时候需要格式化，当SSD之前做过格式化之后直接mount就行。

Is there TRIM (SCSI or block discard) support for SSD in Red Hat Enterprise Linux? Is TRIM properly transmitted through layers like LVM, MD (software raid), filesystems etc? Is SCSI discard on or off by default for ext4? What is fstrim tool and how can we use discard function to reclaim my unused disk space for filesystems on ssd disk drives?

Which disk scheduler should you use with high performance SSD and NVMe storage on RHEL 8? Which disk scheduler is used by default? Environment. Red Hat Enterprise Linux (RHEL) 8