After spending the last hour or so looking into bcache, I've found it pretty hard to locate any good info on CentOS 7/RHEL 7. Todd, you're suggesting that bcache would come in handy if editing over a network, correct? If so, I can understand why using a caching system with a NAS would be worth the setup. Contrary to my previous post, I'm still on the edge about using a caching system for my workstation. The RAID is fast enough as is, and the media drive isn't really accessed too much to begin with. I'm just trying to find something to use the 120GB SSD, maybe dedicate it for Mari projects but those eat space if I remember correctly. It's performance isn't that great either, but it's better than a regular HDD. Formerly, it was an OS X drive for music creation, but I'm trying to refocus myself and dealing with a hackintosh again will just be an added hassle.

Also, I'm fairly new to the 'mailing list' way of doing things, are you guys responding through email? I'm still trying to figure out how to get past posts appended to mine. Sorry for the novice-ness!

I'm inclined to follow what you said, Bjorn. Looking into LVM cache and bcache and there's a lot of useful information. I noticed a lot more people leaning towards bcache, though. It seems simple enough to setup (relatively speaking), so what kind of configuration or tuning would be needed past that? If it doesn't end up working, I could always just return the drive to its previous state as an OS X drive, but I'd rather not. I'm considering taking the 2 identical HDD's and re-raiding them into a 2TB RAID0 like I have on Windows. I use this as a scratch/cache disk for apps, it especially comes in handy for simulations. In an effot to remain consistent with what I already use, here's the setup I'm looking at: 250GB SSD = / and /home (coding projects or small media projects) 250GB SSD = Main work drive for projects 1TB HDD     = Main Media drive (where I transfer older projects and host things like movies, etc) Projects will likely get compressed before going here. 2TB RAID0  = Cache disk for all apps and simulations. I would look into NVME drives, but their limited capacity don't warrant the swtich yet. 120GB SSD = bcache disk A question about bcache: Can I use bcache for both the RAID array and the media drive? Would I have to create 2 partitions on the SSD, one for each backing device? Or should I exclude the RAID from this completely; I usually get upwards of 300MB read/write on it, and I can't think of why it would be read/written non-sequentially. One of the benefits I saw of bcache was that it ignored sequential reads or something like it, which would be super useful when reading media files and could reduce the wear of the SSD. This will be done on a completely clean system, all data will be dumped into dropbox before installation.

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I'm inclined to follow what you said, Bjorn. Looking into LVM cache and bcache and there's a lot of useful information. I noticed a lot more people leaning towards bcache, though. It seems simple enough to setup (relatively speaking), so what kind of configuration or tuning would be needed past that? If it doesn't end up working, I could always just return the drive to its previous state as an OS X drive, but I'd rather not.

I'm considering taking the 2 identical HDD's and re-raiding them into a 2TB RAID0 like I have on Windows. I use this as a scratch/cache disk for apps, it especially comes in handy for simulations. In an effot to remain consistent with what I already use, here's the setup I'm looking at:

250GB SSD = / and /home (coding projects or small media projects)

250GB SSD = Main work drive for projects

1TB HDD     = Main Media drive (where I transfer older projects and host things like movies, etc) Projects will likely get compressed before going here.

2TB RAID0  = Cache disk for all apps and simulations. I would look into NVME drives, but their limited capacity don't warrant the swtich yet.

120GB SSD = bcache disk

A question about bcache: Can I use bcache for both the RAID array and the media drive? Would I have to create 2 partitions on the SSD, one for each backing device? Or should I exclude the RAID from this completely; I usually get upwards of 300MB read/write on it, and I can't think of why it would be read/written non-sequentially. One of the benefits I saw of bcache was that it ignored sequential reads or something like it, which would be super useful when reading media files and could reduce the wear of the SSD. This will be done on a completely clean system, all data will be dumped into dropbox before installation.

For many years, XFS's performance advantages over other filesystems meant users were willing to tolerate some of the more inconvenient aspects of using it, such as recovering from file system corruption. I am not sure if that is still an issue today. Surprised to learn that its now default on some Linux distros today.

• XFS and Ext4 are both very stable and have been for a while (years). One of them have a more robust test suite, which the other (and most other fs) use as well.
• Looking at public benchmark comparisons, XFS and Ext4 are roughly comparable in performance, if configured for comparable robustness.
• XFS is better for larger (30T+) file systems.

Mike, in your case, I'd say ext4 and xfs are equivalent. I'd probably:

• Use ext4.
• Configure the 1x 120GB SSD as a cache for the larger disks. Bcache works really well, but needs to be tuned for high performance workloads.
  • If you lose the cache disk, then there is no data loss.
  • When you reboot the workstation, the bcache is still hot and active.

XFS being the default was most of the reason why I used it so often. Those changes you speak of in the 4.8 kernel, however  good they may be, are not currently applicable though because RHEL/CentOS 7 run off the 3.10.x kernel. That's good info though! I believe XFS is used more in server space because of it's enlarged drive capacity, which is well over that of Ext 4.

Would you recommend formatting all the drives to Ext 4? I usually mix things up, on Windows I have NFTS for boot, HFS+ on 2 other drives (dual-booting Hackintosh), exFAT on my work SSD, and NFTS for the RAID0 drives. I'm simply not aware enough to think of whether there's a benefit to doing this or not.

- Mike

I use ext4 on all my stuff since it is also readable via windows in a pinch. I've never had any bad experiences with it, so I've never felt the need to look at xfs.

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