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26 votes
Accepted

Linux - RAM Disk as part of a Mirrored Logical Volume

To note, we would like to avoid merely RAM caching the files with the OS, but if we can get the same performance as a stand-alone RAM disk, that could work. We initially avoided this since often times ...
  • 437
13 votes

Linux - RAM Disk as part of a Mirrored Logical Volume

This could be hacked together, but it is a bad idea and likely has multiple issues with reliability and maintainability. I think a RAID1 of RAMdisk and physical disk would be limited to the ...
8 votes

Linux - RAM Disk as part of a Mirrored Logical Volume

First off, a RAM disk is almost never the correct answer on Linux. Because it is a block device, you end up with any read having to go through the block layer, and the filesystem, and the regular VFS ...
7 votes

Linux - RAM Disk as part of a Mirrored Logical Volume

I have done something like this using AWS ephemeral disks, which are very fast but do not survive a power off/on cycle. We had a "seed-disk" which was a normal cheap EBS volume of GP2 (GP3 ...
  • 2,289
7 votes

Linux - RAM Disk as part of a Mirrored Logical Volume

If you need persistence, a RAMDISK is not the correct solution. I strongly suggest to invest in a pair of fast (read: enterprise-grade, with powerloss protection) NVMe disk to put in a classical RAID1 ...
  • 44.5k
4 votes

Linux - RAM Disk as part of a Mirrored Logical Volume

If you have this much free ram (that can hold most of these files and their metadata) chances are that they mostly reside in the RAM cache and your limiting factor is not reading, but writing them. If ...
  • 614
3 votes

HP Raid Controller p420i 18TB disk support on DL380 Gen8?

Consider yourself lucky you came here at this stage, and that this didn't work. Firstly you're not supposed to run non-HPE disks on HPE disk controllers, I know some work but we've had a lot of people ...
  • 100k
3 votes

Linux - RAM Disk as part of a Mirrored Logical Volume

Memcached, Redis You basically described Memcached, and somewhat Redis. Both are good at caching, Redis has better support for persistence. Note that you can only gain "all" the performance ...
2 votes
Accepted

dell R730xd disk size less then total disk size after raid 0

In "pure" RAID mode, the smallest disk commands the maximum space that can be used for each disk. In other words, by mixing your 25 disks, you have a total of 25*300 GB == 7500 GB == 6985 ...
  • 44.5k
2 votes

Which RAID is best for private use of NAS

Mathematically it is a terrible idea to use RAID 5 on any HDD that is larger than 2 TB - your chance of a read error WHILE reconstructing is too high. RAID 6 is the only answer here. That is the case ...
  • 51k
1 vote

HP Raid Controller p420i 18TB disk support on DL380 Gen8?

Try to work with period-correct equipment. Gen8 HPE hardware is circa 2012-2015... So 10 year-old technology at this point. 18TB disks showed up around 2019/2020. You should focus on using more ...
  • 195k
1 vote

mdcheck hangs when attempting to stop check

It's probably this bug: https://lore.kernel.org/linux-raid/aa9567fd-38e1-7b9c-b3e1-dc2fdc055da5@molgen.mpg.de/ See also AskUbuntu: https://askubuntu.com/q/1428232/336440 If that is indeed your issue,...
1 vote

What is the fastest and safest RAID combination for SATA drives?

The Subject of File Server is deep. However very important aspects are easy to inform about. In the order of importance: For critical data you need server class cpu and ECC ram Against bit rot you ...

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