sudarshan sridhar wrote: > Hi *bu manzhao,* > ** > * *Thank for you quick response. I have some further queries to your > answer (wirtten with <sridhar> tag). It would be great if you could > provide inputs for them to understand ZFS better. > > ZFS is base in storage pool, and a pool is consist of some vdevs in > tree structure. There is only one root vdev for each pool, and any > number of vdevs as the root's children. > > <sridhar> 1. What exactly a Pool represents?. Let say I have a > workstation with a single hard disk of a size 100Gb. If I create a > zpool and then a zfs how the relation between these tow are shown with > vdev ( the picture provided on ondiskformat pdf).
A storage pool (zpool) describes the relationship of the hardware devices to the pool. A storage pool can contain multiple file systems, by default there is a file system with the same name as the storage pool. > 2. Since ZFS can have multiple pools and each pool is having its own > "root vdev" then how "root vdev"s are interlinked and how ZFS > maintains "root vdev" list and where exctly? There is no "interlink" between storage pools. The configuration of each storage pool is stored inside the storage pool. I hope this is clear in the on-disk format description. -- richard > > > Top-level vdev can be logical vdev or physical vdev. If a top-level > vdev is a logical vdev, it's type can be mirror or raidz and so on, > except disk. And if the top-level vdev is a mirror, then it can be > consist of two or more device. A top-level vdev also can be a physical > vdev and linked to the root vdev directly. > > <sridhar> Thank you for the explanation. Now i have a better > understanding towards Top-levev vdev and physical vdev. > > A pool can be represented as a nvlist in implementation. A nvlist is > a list of a vdev's properties, and each property of vdev organizes as > name/value pair, like (name, value). Two key properties of the tree > structure are vdev_tree and chlidren. Nvlist and nvpair are all data > structure which you can find in soure browser, they define as nvlist_t > and nvpair_t namely. > > <sridhar> If ZFS on a machine is having multiple pools (i.e multiple > root vdevs) how it will be inter related?. > > For more information about vdev and tree structure, you can see the > ZFS On-disk format in > http://www.opensolaris.org/os/community/zfs/docs/ondiskformat0822.pdf > > <sridhar> Thank you for providing the link. I am trying to understand > the layout form the same pdf only. > > Thanks & Regards, > sridhar. > > ------------------------------------------------------------------------ > Never miss a thing. Make Yahoo your homepage. > <http://us.rd.yahoo.com/evt=51438/*http://www.yahoo.com/r/hs> > ------------------------------------------------------------------------ > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
