Bcache is a Linux block layer cache that uses SSDs to cache other block devices.

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50
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4answers
29k views

How do I install and use flashcache/bcache to cache HDD to SSD?

I want to know if there is anyone who has tried installing and running their kernel built with flashcache or bcache for SSD caching? How did you manage to do it?
22
votes
2answers
9k views

What are the advantages/disadvantages of different SSD to HDD cacheing options (dm-cache, flashcashe…)?

There appear to be various different technologies available to use an SSD to act as a cache for HHDs. The ones I know of: dm-cache (by Redhat - in the 3.9 Kernel, so it should be in ubuntu 13.10) ...
8
votes
2answers
2k views

How to install Ubuntu with both disk encryption AND SSD caching

I'm using Ubuntu in a corporate environment, and our security policy states that we have to use full disk encryption. I've also got a laptop with a 32GB mSATA SSD and 750GB of spinning rust. My ...
6
votes
1answer
122 views

Got a new SSD, don't want to wear it out but I still want to use some of it to store data files together with the old HDD

I've bought a brand new 250GB Samsung 850 EVO for my laptop, that I want to use as primary storage device, together with the old - but still pretty functioning - 250GB 7500 RPM HDD that I put in the ...
5
votes
3answers
5k views

How to setup bcache?

I've tried to set up bcache in Ubuntu 14.04 with a fresh install and an empty /home partition (/dev/sdb2) as a backing device. I have a running system on my SSD and I'd like to use its /dev/sda2 ...
2
votes
3answers
4k views

Does bcache require a fresh installation?

Because my notebook has a SSD and a HDD, I want use the SSD as cache just like Rapid Storage in windows. I find bcache offers this functionality so I decide to try it. I got bcache and bcache-tools ...
2
votes
1answer
5k views

“Device not found or ignored” when creating physical volume with bcache

I'm attempting to create an LVM volume on a bcache device, but getting "device not found or recognized", despite lsblk clearly showing the device, and bcache state showing "clean". OS is Ubuntu 13.10 ...
1
vote
3answers
473 views

Does bcache support use of an LVM logical volume as a cache device?

I've got a 64GB SSD and a 3TB hard drive in my system running Ubuntu 14.04. The SSD has a small root partition with rest of the device allocated to an LVM physical volume. From that LVM physical ...
1
vote
1answer
646 views

error in bcache

I used bcache to cache my 24GB SSD using this tutorial. I tried to back up my HDD with: sudo make-bcache -B /dev/sdb1 But I get this error: Can't open dev /dev/sdb1: Device or resource busy My ...
1
vote
1answer
1k views

What happens in bcache if the cache ssd dies?

I'm creating a NAS and I've been doing a lot of research on the different SSD caches. I have a 120gb ssd which is more than enough for the OS so I want to use most of it as a cache for the md raid5 ...
1
vote
1answer
223 views

bcache is not caching all drives

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 ...
1
vote
1answer
139 views

compressed block device

I wanted to experiment with combining bcache and a compressed block device on a hdd and seeing if this will speedup the boot time. Are there any means of compressing a block device at the block level? ...
1
vote
1answer
113 views

Does using an extended cache improve performance?

Does using a extended cache (readyboost-like) improves the overall performance? I read a lot about it and some says that it's just for old machines with low RAM and also the 480mbit/s of usb2.0 was ...
1
vote
1answer
174 views

Recovering disk with corrupted superblock

I am trying to recover a disk that has corrupted superblock but I cant seem to unmount the disk at all. I used bcache for the three extra drive after a reboot one of the drive stopped working. so I ...
1
vote
0answers
355 views

Bcache hangs on Ubuntu 14.04

I successfully setup my system to use bache in /home partition (200GB SSD partition as cache for 500 GB HDD partition). However, I keep receiving these messages: INFO: task bcache_writebac:222 ...
1
vote
1answer
773 views

Reccomended options for mounting /dev/bcache0 as /home

I have set up /dev/sda3 on my SSD to cache /dev/sdb3 on my HDD as /dev/bcache0 using bcache in Ubuntu 13.10 (kernel 3.11.0-14-generic). I have formatted it as ext4. I currently mount / (on my SSD) ...
0
votes
2answers
1k views

Using btrfs with bcache on /

I am using btrfs with bcache for / on Ubuntu 13.10. It's fast. Unfortunately, during normal boots the step "Scanning for btrfs filesystems" fails. To successfully boot I have to enter recovery mode ...
0
votes
1answer
157 views

If I convert my Ubuntu into Xen hypervizor, will I lose access to the bcache devices?

I'd like to test Xen a little. For obvious reasons I cannot do it under VirtualBox (or can I?) As I understand, Xen works by changing the kernel, thus possibly interfering with the custom kernel ...
0
votes
0answers
25 views

Cache a (non-root) hdd which already has data on it with bcache - possible?

Could not find any recent info on this subject, so here goes! I have a small home server with 2 disks: SSD (120 gb), formatted as /ext4 which has an Ubuntu Server 15.10 install (including /home, ...
0
votes
0answers
59 views

Can't boot to ubuntu after bcache setup

I want to use my small SSD disk (only 8GB) and I found that in Linux I can use bcache. So I want to use cache for my root partition. I installed fresh Ubuntu and from Ubuntu live CD did this: sudo ...
0
votes
0answers
66 views

bcache: permission denied as ROOT on /sys/block/bcache0/bcache/*,

Edit for clarification: I'm doing all this as root, any combination of root or sudo or trying to chmod doesn't seem to work. I was trying to add the UUID to attach, but no go. Permission denied when ...
0
votes
0answers
130 views

Recover bcache backing partition data

I had a bcache setup using a spinning disk and SDD. The SSD cache got busted. Now when I boot from a live CD, I can't mount the backing drive since mount doesn't recognize the bcache filesystem. Is ...