RAID (Redundant Array of Inexpensive Disks or Drives, or Redundant Array of Independent Disks) is a data storage virtualization technology that combines multiple physical disk drive components into one or more logical units for the purposes of data redundancy, performance improvement, or both. This was in contrast to the previous concept of highly reliable mainframe disk drives referred to as "single large expensive disk" (SLED).Data is distributed across the drives in one of several ways, referred to as RAID levels, depending on the required level of redundancy and performance. The different schemes, or data distribution layouts, are named by the word "RAID" followed by a number, for example RAID 0 or RAID 1. Each scheme, or RAID level, provides a different balance among the key goals: reliability, availability, performance, and capacity. RAID levels greater than RAID 0 provide protection against unrecoverable sector read errors, as well as against failures of whole physical drives.

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  1. jeyare

    Tutorial Pitfalls of different SSDs used within RAID

    Intro To be more precise about the headline term – different SSDs in this case – means different SSDs based on using different SSD's internal architecture or subsystems like: SSD controllers SSD built-in cache SSD cell technologies and not about the same SSDs with different capacities only...
  2. M

    Changing RAID Type Speed

    Hi There! Just wondering why the speed to change RAID Types is so slow... I'm currently changing from SHR to SHR-2 on my RS2421+ and I have about 29GB of data. My CPU is usually around 1% utilization as per Performance Monitor and my DSM Desktop Read / Write is between 20MB - 30MB in Task...
  3. M

    Changing RAID Type From SHR-1 To SHR-2

    Hi There! Looking at changing my RAID Type from SHR-1 to SHR-2 since I have a 12 Bay NAS and obviously have the option to expand that to 24 Bays with an expansion unit. Figure I should make the change now before I get more & bigger HDD. Hopefully won't take as long. Currently have Drives in...
  4. S

    Bad sectors while repairing RAID 5 volume. Advice needed!

    Hi looks like I am unlucky. I am in the process of replacing all 4 discs. (DS 918+) After each replace I am doing a volume repair. Up to 3 disks have been replaced and no problems with the repair. After inserting the 4th and last disk and repairing the volume. the process is extremely slow and...
  5. Phone Guy

    HyperBackup failing after raid rebuild

    This is going to be a little confusing, but thanks to @Rusty I finally had HB backing up my source nas to a destination nas nightly, working 100% no issues. BUT then I had a raid pool issue the other day on my TARGET nas and the raid pool had to rebuild 1 drive because it reported crashed (long...
  6. C

    BTRFS Volume Smaller Than Raid Calulator

    Hey All, Quick question, I have 4x 4TB Ironwolfs in a ds920+, I noticed that the total SHR size is only 10.5TB. Synology calculator shows it as 12TB. Is this normal? Im pretty sure I built the pool with all 4 4TB drives in it. I am also setting up a ds918+ that had 1x 2TB and 2x 1TB and am...
  7. S

    How to upgrade HDDs? DS218+, 2x12TB -> 2x16TB, no RAID

    Hello, I'm a Synology greenhorn and I would like to ask how to do an upgrade of HDDs in my NAS Synology DS218+. I have 2x 12TB HGST now and I want to change it to 2x 16TB HGST. Each drive has its own volume - no RAID (I backup it from time to time to external drives). So I can not use something...
  8. M

    DSM 6.2 RAID 1 volume crash after power outage. Need advice.

    Hi! After moving my NAS to a different location, it turns out they do have power outages weekly... As a result NAS doesn't work properly after forth power outage. Setup: DS918+ with DSM 6.2 4+4 GB RAM (upgraded with official Synology RAM) No SSD cache 4x Seagate IronWolf 4TB (all formatted...
  9. rajalot

    After a system partition failure and just avoiding major data loss, I'm looking for some advice on the best configuration/RAID setup for my DS218Play!

    Hey everyone - hope you've been keeping safe and well :) I recently experienced a System Partition Failure due to a dislodged drive - therefore reverting the volume to Read only status. I had a single volume configuration, with a JBOD Raid Type. So after spending a good week and a half copying...
  10. J

    Need help figuring this out - DS218+ HDD failure, Plex migration to SSD and different raid configuration

    So, this is a head scratcher for me and need help figuring this out. In an endeavor to ensure that this goes according to plan, I look to you, the Synology geniuses, to guide me. I currently have the Synology DS218+ that I use as a Plex Media Server but also use for backups. One of my hard...
  11. D

    Can I do this with DS920+ Raid 1 and a plain drive

    I want to have 2 drives in a mirrored configuration and one drive as just a plain drive. The plain drive will just host a bunch of pictures, that are already backed up to blu-ray. After a lot of reading on the net, I know it can be done with TrueNAS but I am not sure how this would be done...
  12. animBacker857

    Picking HDDs and Compatibility Advice

    Hello again. Been loving this forum and am learning a lot. I'm nearing my first NAS purchase, a Synology 1821+, and am checking Amazon for drives to get it with (have good experience with them and am unsure of other UK retailers like Scan and Box). The plan was to perhaps get 2 8TB drives to...
  13. P

    Storage pools/volumes and RAID type

    Hi, fairly new to the world of Synology NAS. I am about to take delivery of a DS920+ with 4 times 4TB. My question is about the storage pools/storage volumes. I would like to pair the hard drives as follow: one pair for business and one pair for personal stuff (for each pair there is the main...
  14. M

    New 576TB NAS, pool & RAID planning (SA3600 + 2 exp)

    Hi, This isn't my first NAS rodeo, but first time we're giving Synology a serious chance at our company. The hardware arrives in a few days, and I want to plan the volume makeup ahead of time. SA3600 (128GB RAM) + 2 x RS1222sas expansion chassis, full with 36 x 16TB Toshiba enterprise drives...
  15. RoCaRay

    Selecting a RAID Level - Wikipedia Resource

    In addition to Synology's documentation, there are three Wikipedia articles that might be helpful to some of our members who are in the process of selecting a RAID level that will best meet their requirements. These articles include many references and external links for those wanting a deeper...
  16. I

    Add extra storage to volume

    Hello, I am new to a NAS Synology DS220+ and I can't figure something out. At first I had one Seagate 4TB HDD, but I want to expand my storage with another 4TB (8TB total). (The backup is done on another external HDD, which means I don't need to replicate the data.) I have bought another...
  17. B

    DSM 7.0 ds920+ hotswap, change raid, bigger drives and some questions in general

    Hi guys, got currently raid1 2x1tb drives (black and blue wd, old one) and just bought 4x4tb wd red plus. Now i wonder how i should make changes. End concept is 4x4tb raid5 or 6 maybe. How to start? I am not sure if i can do this: 1. Use 2 new 4tb drives, on one of them copy existing data from...
  18. G

    DSM 7.0 Not seeing an increase in volume after replacing smaller drives with larger drives in an SHR raid

    I have 4 disks in an SHR 1 array on a system using DSM 7. This is my first NAS so I did not upgrade from an older version of DSM. I started with 2x6TB and 2x16 TB disks The storage pool showed I have 25.5 capacity. I replaced one of the 6TB drives with a 12TB drive and the storage pool still...
  19. _vic_

    DS1821+ and two types of RAID on the 8 HDD

    Hello, I have a question on the new DS1821+: is it possible to configure the first 2 HDD with a RAID1 and the last 6 HDD with a RAID6? At the moment I am using a DS713+ with 2x 6TB in RAID1 and a DX513 with 5x 3TB in RAID6. I'd like to keep some data on a mirrored system for a quick and simple...
  20. A

    2x3TB Raid 0 Setup

    I have 2 x 3TB raid 0 from my previous WD Duo Book. The WD Duo Book is damaged and i bought a DS1621xs+ intend to replace it. How can i setup so can read from my previous 3tb raid HDDs without losing the data? Thank you