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Questions tagged [raid-5]

A type of RAID redundancy that includes parity data spread across a number of member disks

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How does parity work on a RAID-5 array?

I'm looking to build a nice little RAID array for dedicated backups. I'd like to have about 2-4TB of space available, as I have this nasty little habit of digitizing everything. Thus, I need a lot of storage and a lot of redundancy in case of drive…
Naftuli Kay
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Can I set up a RAID 5 with a bunch of drives of different sizes?

I currently have 3 1TB drives, a couple 500GB ones and some 750GB ones. Can I put them all in a RAID 5 configuration or do they need to be of same size?
n0pe
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How do I reactivate my MDADM RAID5 array?

I've just moved house which involved dismantling my server and re-connecting it. Since doing so, one of my MDADM RAID5 arrays is appearing as inactive: root@mserver:/tmp# cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] [linear] [multipath]…
Jon Cage
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How to calculate the final RAID size of a RAID 5 array?

What is the formula for working out the final RAID size of a RAID 5 array knowing the number of disk and the size of each disk?
GateKiller
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How to force mdadm to stop RAID5 array?

I have /dev/md127 RAID5 array that consisted of four drives. I managed to hot remove them from the array and currently /dev/md127 does not have any drives: cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4]…
matt
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Should I use "Raid 5 + spare" or "Raid 6"?

What is "Raid 5 + Spare" (excerpt from User Manual, Sect 4.17.2, P.54): RAID5+Spare: RAID 5+Spare is a RAID 5 array in which one disk is used as spare to rebuild the system as soon as a disk fails (Fig. 79). At least four disks are required. If…
Trevor Boyd Smith
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Looking for an actual experience of RAID 5 2 drive failure?

I'm wondering if anyone has any personal experience of RAID 5 2 drive failure with large drives? As I understand it, the theory is that with large 1-2TB drives, if one drive fails in the raid set, it needs to rebuild everything so is thus hitting…
Brian
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RAID5 vs RAID4 purpose of floating parity

I still did not get why is RAID5 better than RAID4. I understand both computes parity bits that are used for recovering if some failure occurs, the only difference is in storing those parity bits. I have borrowed diagrams from here How does parity…
Wakan Tanka
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Data Recovery from RAID5 disk - Promise Pegasus with Apple OSLion and Thunderbolt connection

I have a Promise Pegasus R6 - 12 TB RAID 5 disk for major storage purposes. One of the six 2TB hard disks were dead and the company provided me with a replacement. When the disk was inserted it installed itself as a separate partition and their…
Bedirhan Ustun
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Find files affected by bad blocks with md-raid5 and LVM

I've been doing a lot of research on this topic over the last few weeks - and I think I'm close to completing my recovery, as much as is possible at least. To make a long story short, I'll just describe the problem without filling in every tiny…
Rob
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How does RAID5 work?

In a raid 5 setup, you get 4 TB of usable space out of 3 x 2 TB disks. How is that possible? Simple minded as I am, I would think that you need 4TB to store your things, and use the remaining 2TB for recovery. But how can I recover 4TB out of only…
exolab
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Practical RAID Performance?

I've always thought the following to be a general rule of thumb for RAID: RAID 0: Best performance for READ and WRITE from stripping, greatest risk RAID 1: Redundant, decent for READ (I believe it can read from different parts of a file from…
wag2639
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RAID 5 Array: Probability of Failing to Rebuild Array

I have a Qnap ts463u-rp data storage array, which contains 4x4TB HDD. my question here is, is it safe to configure 3x4TB as RAID 5? because from what I understood, it's not recommend to configure 12TB storage with RAID 5, because of the…
M. Ahmed
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Bad performance with Linux software RAID5 and LUKS encryption

I have set up a Linux software RAID5 on three hard drives and want to encrypt it with cryptsetup/LUKS. My tests showed that the encryption leads to a massive performance decrease that I cannot explain. The RAID5 is able to write 187 MB/s [1] without…
Philipp Wendler
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Ubuntu Server 14.04 - RAID5 created with mdadm disappears after reboot

This is my first question on superuser, so if I forgot to mention something, please ask. I'm trying to set up a home server which will be used as file server and media server. I installed Ubuntu Server 14.04 and now I'm trying to set up a Raid5…
user318354
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