RAID5 is safe?

[Konfl1kt]

I keep my important data RAID1 now. Want to make RAID5 with one extra HDD. Is anybody here use RAID5? How do you like it? Is it safe?

[jarugut]

The RAID5 is totally safe for the data, this option allow you extend your volume space in more than one disk. You are going to keep 1 fail disk.

The Xpenology itself can change the RAID1 to RAID5 without loss data.

[bearcat]

If you plan to add just 1 extra drive, I would not go for RAID5, as it works much better with a minimum of 5 or 6 drives.

Write (and rebuild) speeds of RAID5 might suffer a bit due to the calculations needed for the parity, but read speed will increase with every drive added.

The downside: for every disk added, the theoretical chance for a failing disk nr. 2 during rebuild will increase.

If you go for RAID6, using 2 disks for parity, it will be safer (but you "loose" another disk in terms of storagespace).

 

 

 

Edit:

when all that is beeing said, my "primary" Documents and Backup NAS, is running RAID5

 

 

 

Edited January 7, 2019 by bearcat

[flyride]

The only RAID mode that doesn't have some level of hardware protection is RAID0 (striping without redundancy).  RAID1/5/6/10 and the SHR1/2 counterparts are all "safe."

 

The thing to consider for RAID5 is when you get to very large drive sizes, that the rebuild time is very long, which means your loss of redundancy is for a long time.  Resist the urge to change something else until your rebuild is complete.

 

All this said, no RAID approach is a substitute for backup.  Don't ever think your data is protected from anything other than a physical disk failure.  You need another copy somewhere else.