{"id":44,"date":"2010-01-18T16:08:50","date_gmt":"2010-01-18T16:08:50","guid":{"rendered":"http:\/\/poojanwagh.opalstacked.com\/techblog\/?p=44"},"modified":"2011-03-21T18:34:21","modified_gmt":"2011-03-21T18:34:21","slug":"freebsd-samba-with-zfs","status":"publish","type":"post","link":"https:\/\/tech.poojanblog.com\/blog\/unix-linux\/freebsd-samba-with-zfs\/","title":{"rendered":"Freebsd + Samba with ZFS"},"content":{"rendered":"

I’ve just set up my new file server for Windows shares. Unfortunately, OpenSolaris doesn’t run on my PortWell machine, and I’ve decided that trying to run Windows within a VirtualBox VM (hosted by OpenSolaris) is a bit too flaky.<\/p>\n

Here’s the set up:Partitioning<\/h4>\n

First, I had to configure my drives to support a raidz configuration. I have a 1TB hard drive (new) and a 250 GB hard drive (old). This was the tricky part. I want a good raidz configuration eventually<\/em>. However, right now, I don’t have the money to buy 2 extra hard drives. So, I partitioned the 1 TB hard drive into (roughly) 250 GB slices, and set up a raidz configuration with the slices and the separate 250 GB hard drive. This step was a bit tricky. The FreeBSD fdisk<\/code> command wants to partition on cylinder boundaries. Additionally, fdisk<\/code> also thinks the hard drive is built up of 121601 cyls \/ 255 heads \/ 63 sectors. If I need to partition on a cylinder boundary, I want each partition to hold 121601\/4 cylinders = 30\u00a0400 cylinders. Which comes out to 488 <\/span>376 <\/span>000 sectors. That’s all good, except fdisk<\/code> throws a wrench in there by adding an unused partition at the beginning of the first partition–I’m guessing for the partition table. So, I had to set that first partition to be a little larger (to account for the extra partition). I added 255*63=16065 sectors to the first partition, requesting 488392065 sectors. In the end, my partitions looked like this:<\/p>\n

[ccp]<\/p>\n

Disk name:\u00a0\u00a0\u00a0\u00a0\u00a0 da0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 FDISK Partition Editor
\nDISK Geometry:\u00a0 121601 cyls\/255 heads\/63 sectors = 1953520065 sectors (953867MB)<\/p>\n

Offset\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Size(ST)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 End\u00a0\u00a0\u00a0\u00a0 Name\u00a0 PType\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Desc\u00a0 Subtype\u00a0\u00a0\u00a0 Flags<\/p>\n

0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 63\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 62\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 –\u00a0\u00a0\u00a0\u00a0 12\u00a0\u00a0\u00a0\u00a0 unused\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0
\n63\u00a0 488392002\u00a0 488392064\u00a0\u00a0\u00a0 da0s1\u00a0\u00a0\u00a0\u00a0\u00a0 4\u00a0\u00a0\u00a0\u00a0 ext2fs\u00a0\u00a0\u00a0\u00a0\u00a0 131
\n488392065\u00a0 488376000\u00a0 976768064\u00a0\u00a0\u00a0 da0s2\u00a0\u00a0\u00a0\u00a0\u00a0 4\u00a0\u00a0\u00a0\u00a0 ext2fs\u00a0\u00a0\u00a0\u00a0\u00a0 131
\n976768065\u00a0 488376000 1465144064\u00a0\u00a0\u00a0 da0s3\u00a0\u00a0\u00a0\u00a0\u00a0 4\u00a0\u00a0\u00a0\u00a0 ext2fs\u00a0\u00a0\u00a0\u00a0\u00a0 131
\n1465144065\u00a0 488376000 1953520064\u00a0\u00a0\u00a0 da0s4\u00a0\u00a0\u00a0\u00a0\u00a0 4\u00a0\u00a0\u00a0\u00a0 ext2fs\u00a0\u00a0\u00a0\u00a0\u00a0 131
\n1953520065\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 5103 1953525167\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 –\u00a0\u00a0\u00a0\u00a0 12\u00a0\u00a0\u00a0\u00a0 unused\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0<\/p>\n

[\/cc]<\/p>\n

ZFS RaidZ<\/h4>\n

Originally, I did this:<\/p>\nzpool create tank raidz2 da0s1 da0s2 da0s3 da0s4 da1s1<\/code>\n

However, I realized a couple things: I’m creating a raidz-2 configuration. So, I’d need at least 3 hard drives for this to be of any use. Even with 3 separate 1 TB\u00a0 hard drives, I’d only have 1 TB of usable space (the other two hard drives are redundant parity storage). That’s a bit expensive. So, I decided to throttle down to raidz-1. If a hard drive fails, I should have enough time to replace it before a second hard drive fails. So, I did the following:<\/p>\nzpool create tank raidz da0s1 da0s2 da1s1<\/code>\n

Yup: I’m not using da0s3 nor da0s4. So, there’s roughly 500 GB of space going unused. This isn’t that big of a deal, because when I need the space, it’s probably time to buy an extra hard drive. Also, at the rate my family consumes data, it could be a year before we miss the space. (In retrospect, I probably should have bought two 500 GB hard drives rather than the 1 TB hard drive in the first place.)<\/p>\n

User Storage Areas<\/h4>\n

I created a place to house the Windows user directories:<\/p>\n

zfs create \/tank\/Users<\/p>\n

I then used the following script to create user ZFS filesystems under the \/tank directory, for each user, and with compression on for the Documents<\/code> directory:<\/p>\n<\/p>\n

#!\/bin\/sh<\/p>\n

u=”$1″
\nzfs create tank\/Users\/$u
\nchown $u:$u \/tank\/Users\/$u
\nfor d in “Documents” “Music” “Videos” “Pictures”; do
\nzfs create tank\/Users\/$u\/$d
\nchown $u:$u \/tank\/Users\/$u\/$d
\ndone
\nzfs set compression=gzip tank\/Users\/$u\/Documents
\n<\/code>\n

Samba<\/h4>\n

I set up the samba shares to use this \/tank\/Users<\/code> directory rather then the default home directories. I edited the following in \/usr\/local\/etc\/smb.conf<\/code>:<\/p>\n<\/p>\n

[homes]
\ncomment = Home Directories
\nbrowseable = no
\nwritable = yes
\npath = \/tank\/Users\/%u\/<\/p>\n

<\/code>\n

After that, a few adduser<\/code> and smbpasswd -a<\/code> commands and things were all set. I’m now using Allway Sync<\/a> to synchronize my windows machines to the file server.<\/p>\n

Kernel Tuning<\/h4>\n

ZFS requires a lot more memory from the kernel than the default FreeBSD provides. The tuning guide<\/a> says that I need to rebuild the kernel with KVA_PAGES=512<\/code>. Perhaps. However, for right now, I’m going to try and get by with the following additions to loader.conf from http:\/\/www.daemonforums.org\/showthread.php?t=4200:<\/p>\nnewsystem# cat >> \/boot\/loader.conf << __EOF__
\nvfs.zfs.prefetch_disable=0 # enable prefetch
\nvfs.zfs.arc_max=134217728 # 128 MB
\nvm.kmem_size=536870912 # 512 MB
\nvm.kmem_size_max=536870912 # 512 MB
\nvfs.zfs.vdev.cache.size=8388608 # 8 MB
\n__EOF__<\/code>\n