Changes between Version 43 and Version 44 of FAQ

Timestamp:

2011-07-19T03:46:54Z (13 years ago)

Author:

T_X

Comment:

--

FAQ

@@ -31 +31 @@
 '''Q: Can there be more than one storage folder on a storage node? So if a storage server contains 3 drives without RAID, can it use all 3 for storage?'''
 
-A: Not directly. Each storage server has a single "base directory" which we abbreviate as $BASEDIR. The server keeps all of its shares in a subdirectory named $BASEDIR/storage/shares/ . (Note that you can symlink  this to whatever you want: you can run most of the node from one place, and store all the shares somewhere else). Since there's only one such subdirectory, you can only use one filesystem per node.On the other hand, shares are stored in a set of 1024 subdirectories of that one, named $BASEDIR/storage/shares/aa/, $BASEDIR/storage/shares/ab/, etc. If you were to symlink the first third of these to one filesystem, the next third to a second filesystem, etc, (hopefully with a script!), then you'd get about 1/3rd of the shares stored on each disk. The "how much space is available" and space-reservation tools would be confused, but basically everything else should work normally.
+A: Not directly. Each storage server has a single "base directory" which we abbreviate as $BASEDIR. The server keeps all of its shares in a subdirectory named $BASEDIR/storage/shares/ . (Note that you can symlink  this to whatever you want: you can run most of the node from one place, and store all the shares somewhere else). Since there's only one such subdirectory, you can only use one filesystem per node.On the other hand, shares are stored in a set of 1024 subdirectories of that one, named $BASEDIR/storage/shares/aa/, $BASEDIR/storage/shares/ab/, etc. If you were to symlink the first third of these to one filesystem, the next third to a second filesystem, etc, (hopefully with a script!), then you'd get about 1/3rd of the shares stored on each disk. The "how much space is available" and space-reservation tools would be confused (including making the 'reserved_space' parameter unusable), but basically everything else should work normally.
+
+A cleaner solution might be to use LVM instead, which can combine several physical disks (or loop devices consisting of common files) to a single logical volume. This logical volume can then be mounted (not symlinked!) to $BASEDIR/storage. It also is way more flexible solution, new disks can then be added seemlessly to LVM.
 
 '''Q: Would it make sense to not use any RAID and let Tahoe-LAFS deal with the redundancy?'''