Unix and Linux Stack Exchange
Unix and Linux Stack Exchange

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.

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bcache on md or md on bcache

bcache 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. If I understand correctly, an SSD* could be assigned to cache multiple backing HDDs, and then the…
user12810
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How to use an SSD for caching, so my hard disks can spin down?

I've got a file server with a bunch of disks running together in a BTRFS pool and want to add an SSD for caching. I'm not mainly after speeding up things, but want to catch the regular small accesses to be able to shut down the hard disks most of…
Jens Erat
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How do I remove the cache device from bcache?

I believe, that once I made sure my cache device state is "clean": $ sudo cat /sys/block/bcache0/bcache/state I can just physically remove it from the machine when it is powered off or boot with liveCD and clean the superblock with: $ sudo dd…
Adam Ryczkowski
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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 if it was possible to create a multi-tier caching…
Swivel
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How to restart a 'stopped' bcache device?

I need to upgrade some drive firmware and I'd like to shut down bcache for the duration. The docs show how to stop a bcache device: stop Write to this file to shut down the bcache device and close the backing device. For me that will look like…
user12810
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2 answers

Using multiple SSDs as cache devices with bcache?

If we have three SSDs installed in a system, with a spare partition for the unused space on the SSD (/dev/sda2, /dev/sdb2 and /dev/sdc2). Can bcache be configured to use all three of those partitions to cache a single backing device (such as…
tgharold
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SSD as a read cache for FREQUENTLY read data

I'm looking for ways to make use of an SSD to speed up my system. In “Linux equivalent to ReadyBoost?” (and the research that triggered for me) I've learned about bcache, dm-cache and EnhanceIO. All three of these seem capable of caching read data…
MvG
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Cannot attach cache device to backing device

I have an LVM and I wanted to use bcache to cache one of its LVs. (Yes, I know I could use lvmcache, but I was having issues booting and I gave up using it.) First, I used blocks to convert the LV to a bcache backing device (this seemed to actually…
gen_Eric
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bcache: writeback strategy

I'm using bcache with about 1 TByte of SSD caching for about 40 TByte of data. With writeback and 10% configured for bcache, about 100 GByte of dirty data exist only on the caching devices. I like bcache to keep using the configured percentage of…
C-Otto
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How to remove bcache0 volume?

I've tried echoing to detach and stop. The device will remove itself, but will show up again on reboot. One time on reboot, it restored the mdadm raid I had as a backing device! The other time I disabled the ramdrive that it was paired with, did a…
thistleknot
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Optimizing bcache

I have 3 HDD and 1 SSD, I have successfully mounted all drives to bcache. pavs@VAS:~$ df -h Filesystem Size Used Avail Use% Mounted on /dev/sda1 132G 35G 90G 28% / none 4.0K 0 4.0K 0% /sys/fs/cgroup udev …
bran
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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 is, what is the benefit of using a cachepool…
Swivel
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What is grinding my HDDs and how do I stop it?

Something is grinding my hard disks all the time (a few KBs every second) and I can't seem to figure out what. My configuration: 4 spinning platters (/dev/sd[cdef]) assembled into a raid5 array, then bcache set to cache (hopefully) everything…
velis
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BCache and disk encryption

I recently bought a new laptop with a 16Gb mSATA SSD cache drive. I haven't used that one yet. I have, however, opted for Ubuntu 13.04 with "Full Disk Encryption" for the main partition (is that what's called LUKS?). With bcache making it's way into…
molgaard
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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 configration of those devices to my…
carbolymer
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