Siduction Forum
Siduction Forum => Installation - Support => Topic started by: mylo on 2013/03/29, 12:24:19
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Hi all,
I want to start experimenting with Btrfs.
Has anypne positive or negative experience on running a partition with Btrfs, while the remaining partitions on the physical drive are ext4?
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Yes, I have done that and it worked very well. In fact, the #1 reason I chose Siduction over several other distros is that Siduction handled my btrfs multi-device root partition without a single problem. The other distros would handle it, but needed various workarounds.
Now, my system is completely on btrfs, on a 1.9 TB 2-drive RAID-0 volume. I have had no trouble with it and it has been running this way for almost seven months.
Good luck. Let me know if I can help with anything.
Tim
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Hi timc,
thanks for your helpful experience. I think the advantages of btrfs are mostly in reduced access times or does btrfs also use the disk space more efficient?
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To me, the great advantage is quick and easy volume and subvolume management, especially with multiple devices. I also have found disk write times to be very fast.
Sorry, but I am not sure about how efficient it may or may not be with disk space utilization. I have 3 TB of internal storage and another 2 of external, so space utilization is not something I really worry about. However, btrfs also has quick and easy compression, which I do use. The lzo compression actually improves overall performance.
Tim
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Btrfs cannot convince me, as 86 GB in gparted mutate to 20 GB in krusader. That seem's strange to me.
Do I have to adapt ../fstab though?
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The only advantage I can think of to run btrfs in a partition would be if there is some reason you want snapshots of the partition. There is no performance advantage over ext4 -- if you check the Phoronix benchmarking articles btrfs is still a bit slower than ext4.
Where btrfs really shines, and where I use it, is to make a multi-device filesystem with RAID 0 and RAID 1 characteristics. So I have 2 WD-1002FAEX SATA 3 drives in a btrfs filesystem, with about 800GB of user data on it:
root@imerabox:/# btrfs fi df /mnt/DATA
Data, RAID0: total=846.00GB, used=795.18GB
Data: total=8.00MB, used=7.62MB
System, RAID1: total=8.00MB, used=64.00KB
System: total=4.00MB, used=0.00
Metadata, RAID1: total=2.00GB, used=1.44GB
Metadata: total=8.00MB, used=0.00
It is pretty fast, and a good way to use these drives.
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Hi dibl,
thanks for your helpful informations. So I wait to using btrfs when my storage comes.
I adapted fstab from ext4 to btrfs, but the 20 GB remain. I have there an other fault, I have to detect..
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The /etc/fstab line to mount 2 drives with a btrfs filesystem already installed is like this:
UUID=66d73a79-8000-498b-9393-c808ca29070e /mnt/DATA btrfs device=/dev/sdd,device=/dev/sde,compress=lzo,space_cache,inode_cache 0 0
You can find the necessary UUIDs with blkid:
root@imerabox:/home/don# blkid -c /dev/null -o list
device fs_type label mount point UUID
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/dev/sda1 ext2 /boot ac7da829-aebb-46f0-806c-04a4d81a945a
/dev/sda2 swap <swap> 0d939b7d-48f1-47dd-aebe-77e7bd8c3503
/dev/sdb1 ext4 / bea3a748-3411-4024-acd0-39f3882ddaf9
/dev/sdb2 ext4 SDA2 /mnt/SDA2 8cfe2acc-7572-4b45-b25f-ed021bb1d78b
/dev/sdc1 ext4 revodata /mnt/REVODATA ec21f5b3-7fd4-4f4b-af8d-cf787b147ae8
/dev/sdd btrfs (in use) 66d73a79-8000-498b-9393-c808ca29070e
/dev/sde btrfs (in use) 66d73a79-8000-498b-9393-c808ca29070e
Note that both /dev/sdd and /dev/sde show the same UUID -- that is the UUID of the btrfs filesystem, which was installed on both drives, according to the btrfs wiki (https://btrfs.wiki.kernel.org/index.php/Using_Btrfs_with_Multiple_Devices).
If you run the simple "blkid" command, then you can see the "sub-UUID" numbers for the drives:
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/dev/sdd: UUID="66d73a79-8000-498b-9393-c808ca29070e" UUID_SUB="81002952-c5a8-4581-9489-eb2b9a4de44f" TYPE="btrfs"
/dev/sde: UUID="66d73a79-8000-498b-9393-c808ca29070e" UUID_SUB="4f82d6d3-498a-4b0f-910f-10a891d64043" TYPE="btrfs"
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Hi dibl,
yes I forgot to adapting the UUID. Now it works fine! Thanks!
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Personally BTRfs didn't work for me
I tried twice the installation
- 1st time was: BTRfs with encryption and hibernation SWAP
- 2nd time was: BTRfs with encryption and swap in a file
both time LUKS (encryption) and MDADM (softraid) gave me a hard time and the filesystem (/) end in read only.
[UPDATE] AhhA! to be sure to not giving false impression on BTRfs, I just installed 2 more times
- 3rd: on the same computer of the 1st and 2nd try but with an encrypted ext4 without Hibernation SWAP and everything works fine.
- 4th: on a different computer with encrypted ext4 and Hibernation SWAP and I ended with the same issue around MDADM and luks with a read only filesystem.