<div>
If your NAS has the support for RAID 6 you should use it. RAID 6 can protect against 2 drive failing at the same time. The problem with RAID 5 is the stress are rebuilding the raid array can make another drive to fail.
</div>


If your NAS has the support for RAID 6 you should use it. RAID 6 can protect against 2 drive failing at the same time. The problem with RAID 5 is the stress are rebuilding the raid array can make another drive to fail.

<div>
So is mean during terastation process &nbsp;of changing harddisk users &nbsp;can not access &nbsp;to the drive ?
</div>


So is mean during terastation process  of changing harddisk users  can not access  to the drive ?

<div>
Yes that's what it means, &nbsp;these cheap-ish NAS drives don't have the juice to rebuild and allow access
</div>


Yes that's what it means,  these cheap-ish NAS drives don't have the juice to rebuild and allow access

<div>
<div class="content wysiwyg-content">
Recently my company Buffalo Tera-station disk 4 was failure,so that,i plug out the failure HDD and replace with new HDD then press button to rebuild the disk.After i press the button to rebuild ,i can see in the console all the user can not access to this buffalo,but too late because i never inform user,some job they doing already lost.I have few question in below to avoid this make mistake again<br />
<br />
1.All the server like HP Proliant DL 380 during rebuilt the disk will effect user or just buffalo tera-station only can be happen like what i described above.<br />
<br />
2.How we can know the disk rebuilding time consuming ?<br />
<br />
3.I have 4 disk and configure RAID 5 ,IF user accidentally plug out two HDD, we can recover the data ?
</div>
</div>


Recently my company Buffalo Tera-station disk 4 was failure,so that,i plug out the failure HDD and replace with new HDD then press button to rebuild the disk.After i press the button to rebuild ,i can see in the console all the user can not access to this buffalo,but too late because i never inform user,some job they doing already lost.I have few question in below to avoid this make mistake again

1.All the server like HP Proliant DL 380 during rebuilt the disk will effect user or just buffalo tera-station only can be happen like what i described above.

2.How we can know the disk rebuilding time consuming ?

3.I have 4 disk and configure RAID 5 ,IF user accidentally plug out two HDD, we can recover the data ?

Buffalo Terastation NAS Disk Rebuilding

Storage devices include any device used for storing and retrieving digital information. Hard disk drives (HDDs) use one or more rigid ("hard") rapidly rotating disks (platters) coated with magnetic material. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored or retrieved in any order and not only sequentially. The primary competing technology for secondary storage is flash memory in the form of solid-state drives (SSDs), but HDDs remain the dominant medium for secondary storage due to advantages in price per bit and per-device recording capacity. CD-RW (Compact Disc-ReWritable) is a digital optical disc storage format that allows information to be stored outside the mechanical HDD.

Storage Hardware

Computer data storage, often called storage or memory, is a technology consisting of computer components and recording media used to retain digital data. In addition to local storage devices like CD and DVD readers, hard drives and flash drives, solid state drives can hold enormous amounts of data in a very small device. Cloud services and other new forms of remote storage also add to the capacity of devices and their ability to access more data without building additional data storage into a device.

Storage

Servers are computing devices that are similar to desktop computers in that they have the same basic components, but are significantly different in size, configuration and purpose. Servers are usually accessed over a network, and many run unattended, without a computer monitor, input device, audio hardware or USB interfaces. Many servers do not have a graphical user interface (GUI), and are configured and managed remotely. Servers typically include hardware redundancy such as dual power supplies, RAID disk systems, and ECC memory, along with extensive pre-boot memory testing and verification. Critical components might be hot swappable, and to guard against overheating, servers might have more powerful fans or use water cooling.