>> On 4/11/2015 at 06:26 AM, in message <u8vlvb-ciu.ln1@xxxxxxxxxxxxxxxxxxx>, Kai Krakow <hurikhan77@xxxxxxxxx> wrote: > Lidong Zhong <lzhong@xxxxxxxx> schrieb: > >>>>> On 4/9/2015 at 02:56 AM, in message >>>>> <98agvb-l7r.ln1@xxxxxxxxxxxxxxxxxxx>, Kai > > Krakow <hurikhan77@xxxxxxxxx> wrote: > >> David Mohr <david@xxxxxxxx> schrieb: > >> > > I am curious about how rootfs and home share the SSD dynamically. Are they > > on the same partition? Sorry for stupid questions since I just touched > > bcache recently. > > Cache and backing device association is not 1:1. You can attach multiple > backing partitions (even from distinct filesystems) to the one and same > caching partition. So, accesses to one of the cached filesystems will go > through the same bcache, thus sharing the cache space through bcache's LRU > implementation (or if you change it from the default, even something else > like LRU). > > Here's my setup (shortened): > > ├─sdb3 8:19 0 79,5G 0 part > │ ├─bcache0 252:0 0 925,5G 0 disk > │ ├─bcache1 252:1 0 925,5G 0 disk > │ └─bcache2 252:2 0 925,5G 0 disk > > with sdb3 being the one and only bcache partition on SSD: > > $ ls -al /sys/fs/bcache/ > insgesamt 0 > drwxr-xr-x 3 root root 0 11. Apr 00:25 . > drwxr-xr-x 11 root root 0 6. Apr 19:07 .. > drwxr-xr-x 7 root root 0 8. Apr 20:33 bf2b67f9-a261-4d27- > a6ef-2961f2ce2cc2 > --w------- 1 root root 4096 8. Apr 20:33 register > --w------- 1 root root 4096 6. Apr 19:08 register_quiet > > $ ls -al /sys/fs/bcache/bf2b67f9-a261-4d27-a6ef-2961f2ce2cc2/ > insgesamt 0 > drwxr-xr-x 7 root root 0 11. Apr 00:25 . > drwxr-xr-x 3 root root 0 11. Apr 00:25 .. > -r--r--r-- 1 root root 4096 8. Apr 20:33 average_key_size > lrwxrwxrwx 1 root root 0 8. Apr 20:33 bdev0 -> > ../../../devices/pci0000:00/0000:00:1f.2/ata3/host2/target2:0:0/2:0:0:0/bloc > k/sdc/sdc2/bcache > lrwxrwxrwx 1 root root 0 8. Apr 20:33 bdev1 -> > ../../../devices/pci0000:00/0000:00:1f.2/ata4/host3/target3:0:0/3:0:0:0/bloc > k/sdd/sdd2/bcache > lrwxrwxrwx 1 root root 0 8. Apr 20:33 bdev2 -> > ../../../devices/pci0000:00/0000:00:1f.2/ata5/host4/target4:0:0/4:0:0:0/bloc > k/sde/sde2/bcache > -r--r--r-- 1 root root 4096 8. Apr 20:33 block_size > -r--r--r-- 1 root root 4096 8. Apr 20:33 btree_cache_size > -r--r--r-- 1 root root 4096 8. Apr 20:33 bucket_size > lrwxrwxrwx 1 root root 0 8. Apr 20:33 cache0 -> > ../../../devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/bloc > k/sdb/sdb3/bcache > [...] > Thank you for your detailed explanation. Regards, Lidong > > -- > Replies to list only preferred. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-bcache" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
