First, HDD for Server and HDD for PC are of course different. Servers generally use SCSI interface hard disks (now SAS has replaced SCSI), while PCs generally use ATA interface hard disks (now SATA has replaced ATA). The advantages of SCSI hard disks are The system occupation is very small. For example, if you copy dozens of GB of data from disk D to disk E, and copy dozens of GB of data from disk E to disk D at the same time, the disk resources should be basically exhausted. Then run CS at the same time. If it is on a PC, these two copy actions will occupy all CPU resources, and CS cannot run at all, but on the Server, these two copy actions will hardly occupy any CPU resources. After reading the memory, it can run very normally and smoothly.
Compared with hard disks of ordinary PCs, hard disks used in servers have the following four characteristics.
1. Fast speed
The hard disk used by the server has a fast rotation speed, which can reach 7200 or 10000 revolutions per minute, or even higher; it is also configured with a large (generally 2MB or 4MB) write-back cache; the average access time is relatively short; the external transfer rate and internal The transfer rate is higher, using standard SCSI hard drives such as Ultra Wide SCSI, Ultra2 Wide SCSI, Ultra160 SCSI, Ultra320 SCSI, etc., the data transfer rate per second can reach 40MB, 80MB, 160MB, 320MB respectively.
2. High reliability
Because the hard disk of the server is running almost 24 hours a day, and bears a huge workload. It can be said that if there is a problem with the hard disk, the consequences will be disastrous. Therefore, current hard disks all adopt S.M.A.R.T technology (self-monitoring, analysis and reporting technology), and hard disk manufacturers have adopted their own unique advanced technologies to ensure data security. In order to avoid unexpected losses, server hard disks can generally withstand the impact of 300G to 1000G.
3. More use of SCSI interface
Most servers use SCSI hard disks with high data throughput and extremely low CPU occupancy. SCSI hard drives must be used through SCSI interfaces. Some server motherboards integrate SCSI interfaces, and some have dedicated SCSI interface cards. One SCSI interface card can connect to 7 SCSI devices, which is unmatched by IDE interfaces.
4. Support hot swap
Hot swap (Hot Swap) is a hard disk installation method supported by some servers. You can pull out or insert a hard disk without stopping the server, and the operating system will automatically recognize the change of the hard disk. This technology is very necessary for a server that runs 24 hours a day.