Hello Chris,

Tuesday, November 25, 2008, 11:19:36 PM, you wrote:

CS>  Suppose that you have a SAN environment with a lot of LUNs. In the
CS> normal course of events this means that 'zpool import' is very slow,
CS> because it has to probe all of the LUNs all of the time.

CS>  In S10U6, the theoretical 'obvious' way to get around this for your
CS> SAN filesystems seems to be to use a non-default cachefile (likely one
CS> cachefile per virtual fileserver, although you could go all the way to
CS> one cachefile per pool) and then copy this cachefile from the master
CS> host to all of your other hosts. When you need to rapidly bring up a
CS> virtual fileserver on a non-default host, you can just run
CS>         zpool import -c /where/ever/<host>.cache -a

CS>  However, the S10U6 zpool documentation doesn't say if zpool cachefiles
CS> can be copied between systems and used like this. Does anyone know if
CS> this is a guaranteed property that is sure to keep working, something
CS> that works right now but there's no guarantees that it will keep working
CS> in future versions of Solaris and patches, or something that doesn't
CS> work reliably in general?

CS> (I have done basic tests with my S10U6 test machine, and it seems to
CS> work ... but I might easily be missing something that makes it not
CS> reliable.)

As long as both systems present disks in the same way (same paths) it
will work as expected. Even if they don't an import should still work
but without the benefit of a cache file.

My understanding is that the the intention behind cachefile property
was to address poor's man clusters and (hopefully) to enhance hastoragplus agent
to make use of it automatically so importing a pool would be quicker
in some environments.

The other problem it addresses is that only pools listed in default
cache file will be automatically imported during os boot.



-- 
Best regards,
 Robert Milkowski                            mailto:[EMAIL PROTECTED]
                                       http://milek.blogspot.com

_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

Reply via email to