SCSI hard drive Data recovery software free download
- Publish Time：2018-09-17 09:27
SCSI hard disk is a hard disk with SCSI interface, which is the abbreviation of Small Computer System Interface. SCSI hard disk has the characteristics of fast interface speed, high performance, large cache capacity and low CPU usage. Therefore, SCSI hard disks are often used in servers and disk array cabinets to store important data. It is because SCSI hard disks are too stable and not as easy to fail as ordinary IDEs and SCSI hard disks. Therefore, many people neglect the importance of data backup. In the event of an unexpected server power outage, the SCSI hard disk may not be recognized, resulting in data loss. So is there a way to recover data from SCSI hard drives?
In fact, as long as the SCSI hard disk is not physically damaged, the hard disk data recovery software can successfully complete the SCSI hard disk data recovery. Because the price of SCSI hard disk is more expensive than ordinary hard disk, it is generally applied to enterprise medium and high-end servers. This type of hard disk data recovery has higher requirements for hard disk data recovery software, and hard disk data recovery software is available for enterprise, professional, and personal versions for different industry needs.
Here, select the enterprise version to experience, download the Professional to get the registration code, install and run. The following page appears, select "Hard Drive".
SCSI hard disk data recovery method
Due to the large size of enterprise data, scanning will take a lot of time. In order to improve the data recovery efficiency of SCSI hard disk, we can enter the "Options" column to pass the scanning conditions of "File Type", "Scan Area" and "Scan Option". Set to speed up scanning.
SCSI hard disk data recovery method 2
After the setup is complete, return to the main page of the wizard and follow the prompts step by step. The data lost by the SCSI hard disk will be recovered soon. Be careful when you save the file in the last step: Always save the data to another disk so that the original disk data is not destroyed.
The scsi hard disk SCSI hard disk is a hard disk with a SCSI interface. SCSI is an abbreviation of Small Computer System Interface. It uses a 50-pin interface and has a similar appearance to a normal hard disk interface. Compared with ordinary IDE hard disks, SCSI hard disks have many advantages: the interface speed is fast, and because it is mainly used for servers, the performance of the hard disk itself is relatively high, the hard disk speed is fast, the cache capacity is large, the CPU usage is low, and the scalability is much better. IDE hard drive and support hot swap.
A SCSI hard disk is a hard disk with a SCSI interface. It is on the server because of its good performance and high stability.
Widely used. At the same time, its price is not cheap, because it is expensive, so it is rarely seen on ordinary PCs.
1. SCSI- began research in 1983. The main features of the SCSI standard developed in 1985 were: support for synchronous and asynchronous SCSI devices; support for seven 8-bit SCSI devices; transfer rate up to 5M/sec; support for WORM (WRITE ONCE READ MANY) )equipment. The SCSI-1 control uses the card ISA bus, which has a maximum connection length of 6 meters and a connector of 50 pins, but is not used because the transmission speed is too slow.
2. The SCSI-2SCSI-2 standard was developed in 1992. It incorporates the following new features into the SCSI-1 standard; supports high-density SCSI connectors; supports CD-ROMs and scanners; SCSI bus with even parity; supports FAST SCSI and WIDE SCSI; supports Tagged Queuing. FAST SCSI is a standard specification for SCSI-2. WIDE SCSI is an enhanced specification that comes with SCSI-2. FAST SCSI enables data transfer speeds of up to 10M/s on SCSI buses, which is twice the speed of SCSI-1 devices. Most SCSI hard drives support the FAST SCSI standard. FAST SCSI devices require synchronous data transfer. When installing a FAST SCSI device, its maximum cable length cannot exceed 3 meters, the connector is 50 pins, and up to 7 devices can be connected. Compared to the FAST SCSI bus, the WIDE SCSI bus can transfer 16 bits of data at the same time, which increases the data transfer rate of WIDE SCSI-enabled devices to 20M/s. And the WIDE SCSI bus can support both 8-bit and 16-bit SCSI devices. When you use the WIDE SCSI controller card, you should note that it can only connect up to 15 SCSI devices. The connector is 68 or 80 pins. The maximum cable length cannot exceed 6 meters.
3. SCSI-3 can support more types of computer hardware than SCSI-2, and the data transfer rate is faster. SCSI-3 supports Ultra SCSI, also known as FAST-20, Doublespeed SCSI, which defines how to transfer 20M of data per second on an 8-bit SCSI bus and 40M of data per second on a 16-bit Wide SCSI bus. When the control card is connected with 50-pin connector and 8-bit data, it can connect 7 SCSI devices in series. The maximum length of the cable is 1.5 meters. When using 68-pin or 80-pin connector, 16-bit data transmission, 15 SCSI devices can be connected in series, the maximum cable length is 1.5 meters; support Fibre Channel, providing transmission rate up to 100M/S; support serial channel, Serially connect 16-32 and SCSI devices. Wide Ultra SCSI (LVD) can also be called Ultra2 SCSI (LVD) LVD stands for Low Voltage Differential Technology. It has a transmission rate of up to 80M/S and uses a 68 or 70-pin interface with a maximum cable length of 12 meters and a maximum of 15 SCSI devices. Most of the SCSI hard drives that began production in 1998 use this standard. For example, Western Digital's Enterprise WDEI8300 and Quantum's Altra3 SCSI Ultrastar support Ultra2 SCSI (LVD) standards. The Ultra3 SCSI Ultra 160MB/S standard, which is the 5th generation SCSI technology, delivers up to four times the performance of Wide Ultra, which has a transfer rate of up to 160MB/s due to Ultra 160 SCSI per clock week. It sends two bits of data instead of one, so it has higher throughput than the Ultra2SCSI standard (up to 80M/S), and it provides a dual-border clocking scheme that allows data and clocks to run at 400Hz. The Ultra 160 SCSI also incorporates Low Voltage Differential Technology (LVD), which features the cost savings of past single-ended technology and the ability to withstand signal noise and low potential drift in high voltage differential technology designs. In November 1999, Quantum launched the Atlas lok and Altas four generations of hard drives that support this standard.
Straight-through SCSI disks provide a way to connect Hyper-V virtual machines to physical storage (as opposed to relying on virtual hard disks). However, it should be noted that the use of straight-through scsi disks has certain limitations.
Straight-through disks were popular before the release of Windows Server 2012. At the time, Hyper-V used a virtual hard disk (VHD) format of up to 2TB, which is not enough for some virtual machines (VMs). Straight-through disks have become popular because they bypass the 2TB storage limit. But in Windows Server 2012, Microsoft introduced the VHDX virtual hard disk format, which is no longer limited to 2TB. 
Compared with the hard disk of a normal PC, the hard disk used on the server has the following four characteristics.
The hard disk used by the server is fast, which can reach 7200 or 10,000 rpm or even higher; it is also configured with a large (usually 2MB or 4MB) write-back cache; the average access time is short; the external transmission rate and internal The transmission rate is higher, and the standard SCSI hard disk 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.
2, high reliability
Because the server hard drive runs almost 24 hours a day, it takes a huge amount of work. It can be said that if the hard disk has a problem, the consequences are unimaginable. Therefore, the hard disk uses S.M.A.R.T technology (self-monitoring, analysis and reporting technology), and the hard disk manufacturers have adopted their own unique advanced technology to ensure data security. In order to avoid accidental losses, server hard drives can generally withstand 300G to 1000G impact.
3, more use of SCSI interface
Most servers use SCSI hard drives with high data throughput and extremely low CPU usage. SCSI hard disks must be used through the SCSI interface. Some server motherboards integrate SCSI interfaces. Some have dedicated SCSI interface cards. One SCSI interface card can connect seven SCSI devices, which is unmatched by the IDE interface.
4, can support hot swap
Hot Swap is a hard disk installation method supported by some servers. It can unplug or insert a hard disk without stopping the server. The operating system automatically recognizes the changes of the hard disk. This technology is necessary for servers that run 24 hours a day.
Scsi hard disk interface
Scsi hard disk interface
The hard disk is divided from the interface. Can be divided into IDE and SATA hard drives and SCSI hard drives (and some products that support PCMCIA interface, IEEE 1394 interface, SATA interface, USB interface and FC-AL (FibreChannel-Arbitrated Loop) Fibre Channel interface, but relatively few) .
One type of IDE is the hard disk we use every day. It is not cheap because of its low price, so it is widely used on PC. However, SATA has gradually replaced the status of IDE hard drives. Become the mainstream of the PC market. Most of the hard disks used on personal computers are SATA interface hard disks.
Another type of hard disk is a SCSI hard disk (SCSI is the Small Computer System Interface). Due to its good performance, such hard disk products are commonly used on servers.
When we measure the performance of a server hard drive, we should mainly refer to the following indicators:
Spindle speed is one of the most compelling performance parameters in addition to capacity in all indicators of the hard disk. It is also the first determining factor in determining the internal transmission speed and sustained transmission speed of the hard disk. Today's hard drives are typically 5400 rpm, 7200 rpm, 10,000 rpm and 15,000 rpm. From the situation, 10000rpm SCSI hard disk has the advantage of cost-effective, is the mainstream of the hard disk, and 7200rpm and below the hard disk is gradually fading out of the hard disk market.
Internal transmission rate
The internal transfer rate is the decisive factor in evaluating the overall performance of a hard disk. The hard disk data transfer rate is divided into internal and external transfer rate and external transfer rate. The external transmission rate is also the burst data transfer rate (Burstdata Transfer Rate) or interface transfer rate, which refers to the speed of outputting data from the cache of the hard disk.
The external transmission rate of Ultra 160 SCSI technology has reached 160MB/s; the internal transmission rate is also called the maximum or minimum sustained transmission rate (Sustained Transfer Rate), which refers to the speed at which the hard disk reads and writes data on the disk. The mainstream hard disk is mostly at 30MB. /s to 60MB/s. Since the internal transfer rate of the hard disk is smaller than the external transfer rate, only the internal transfer rate can be used as a true measure of the performance of the hard disk.
The main manufacturers of SCSI hard drives are: Seagate, Quantum, IBM and WD. SCSI hard drives are more expensive, and SCSI hard drives of the same capacity are more than 80% more expensive than IDE hard drives, so SCSI hard drives are mainly used in medium and high-end servers and high-end workstations.
In order to make the hard disk adapt to the working environment of large data volume and long working time, the server generally adopts.