[zfs-discuss] One dataset per user?

James C. McPherson
2010-06-21T12:59:25Z

On 21/06/10 10:38 PM, Edward Ned Harvey wrote:
>> From: James C. McPherson [mailto:jmcp at opensolaris.org]
>>
>> On the build systems that I maintain inside the firewall,
>> we mandate one filesystem per user, which is a very great
>> boon for system administration.
>
> What''s the reasoning behind it?

Politeness, basically. Every user on these machines is expected
to make and use their own disk-space sandpit - having their own
dataset makes that work nicely.

>> My management scripts are
>> considerably faster running when I don''t have to traverse
>> whole directory trees (ala ufs).
>
> That''s a good reason.  Why would you have to traverse whole
 > directory structures if you had a single zfs filesystem in
 > a single zpool, instead of many zfs filesystems in a single zpool?

For instance, if I''ve got users a, b and c, who have their own
datasets, and users z, y and x who do not:

df -h /builds/[abczyx]

will show me disk usage of /builds for z, y and x, but

/builds/a
/builds/b
/builds/c

for the ones who do have their own dataset. So when I''m
trying to figure out who I need to yell at because they''re
using more than our acceptable limit (30Gb), I have to run
"du -s /builds/[zyx]". And that takes time. Lots of time.
Especially on these systems which are in huge demand from
people all over Solaris-land.



James C. McPherson
--
Senior Software Engineer, Solaris
Oracle