Questions tagged [bcache]
Bcache is a Linux kernel block layer cache. It allows one or more fast disk drives such as flash-based solid state drives (SSDs) to act as a cache for one or more slower hard disk drives.
59 questions
2 votes
1 answer
87 views
Spin down HDD on Server
I'm running Debian 13 (fresh install) and want to use specifically Nextcloud and Immich on docker on an SSD and 2 HDDs with 10TB for data (and the second for raid/snapraid or backups or similar). For ...
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5 votes
0 answers
191 views
Can I prevent ZFS writing to HDD by caching write requests during a time period?
Background I have recently built a NAS/homelab, with one fairly large SSD for system and 3 HDDs in ZFS + RAID-Z1 for data. The setup works great, and I expect it to be on 24/7. However, some services ...
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2 votes
1 answer
288 views
Temporarily disable bcache read caching to run a scrub
I use btrfs atop of bcache. It caches small reads and that works great. When running a scrub of the btrfs however, I'd like those reads to go through to the backing devices because their contents are ...
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6 votes
1 answer
1k views
Equivalent of `btrfs send` and `btrfs recv` for bcachefs
I'm using a setup I consider to be rather fragile and prone to failure involving LUKS, LVM, btrfs, and bcache. I have used btrfs for a long time, and have never experienced any significant issues with ...
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0 votes
1 answer
607 views
Bcache is not being utilized, slow raid/transfer rates
I have a 512 GB SSD serving as a cache for a 42 TB RAID using Bcache on Ubuntu Server. To test its performance, I transferred a game containing both large and small files. When transferring files to ...
1 vote
1 answer
727 views
Cannot register bcache backing device: Invalid argument
When I try to register my bcache backing device: echo $backing | sudo tee /sys/fs/bcache/register I get Invalid argument The cache device is already registered.
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2 votes
1 answer
137 views
Using hibernate with bcache
I have writethrough bcache working on Debian Sid with an underlying LUKS + LVM. My swap partition (already present) is lying unused as an LVM volume. I know that I am supposed to stop bcache before ...
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1 vote
1 answer
2k views
How can you check how much of a bcache cache is currently in use?
I've got a setup that includes a bcache cache device serving multiple backing devices. I would like to know how much of it is currently in use because bcache only caches certain kinds of data.
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4 votes
1 answer
980 views
Is it possible to avoid cached data duplication in bcache and Btrfs RAID1?
There is a possibility to attach single bcache cache drive to multiple backing devices. Since bcache is not aware about filesystem which lies on top, this means it is not aware about any software RAID ...
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1 vote
0 answers
503 views
bcache on btrfs - drives won't stay statically mapped - order changes automatically
Just an upfront, I've been in IT professionally for 30 years, yet mostly on the Windows systems side of the house. I've taken quite an interest in Linux as of late to expand my horizons, yet this may ...
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3 votes
0 answers
1k views
Use SSDs as persistent buffer for HDDs to decrease power usage
similar questions have been asked multiple times ... How to use an SSD for caching, so my hard disks can spin down? Caching write changes on SSD to avoid HDD spin-up? ZFS, but (probably) not L2ARC ...
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6 votes
2 answers
2k views
LVMCache: Why use a cachepool instead of a cachevol?
I'm aware of the differences between a cachepool and cachevol. Cachepool separates the cache data and metadata into two separate volumes, whereas a Cachevol uses a single volume for both. My question ...
- 266
9 votes
1 answer
1k views
Using LVMCache or BCache for Hot-Warm-Cold Caching
I've recently reconfigured my current debian machine with three different drives: An SLC SSD, a QLC SSD, and a 4TB HDD. I've been toying around with lvmcache and other utilities, and I wanted to know ...
- 266
2 votes
1 answer
382 views
bcache fails to attach local ssd as caching device in google cloud
I'm trying to setup bcache in an instance in google cloud using a raid of local SSDs as caching device but everything fails in the attach phase of the process. For testing purposes I created a new ...
- 21
3 votes
0 answers
397 views
Troubleshooting slow writeback on bcache
can somebody give me a hint, how to troubleshoot bcache in writeback mode? I'm using a RAID 1 (2x500GB SSD) as caching device for the RAID 1 backing device (2x16TB HDD). Dirty data of bcache is not ...
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