More comments/questions after having spent more timing examining the
disk layout modelling:)
4.1.1:
The data model assumes that only one VTOC (DiskSlices_t) can exist
on disk. On X86, the DiskSlice_t is associated with a parition. Will the
assumption on X86 that only one partition can contain a VTOC hold true
in the future? Will ZFS make this irrelevant?
--------------------------------------------------------------------------------------
typedef struct {
char *diskName; /* Disk Name
for look up */
PartitionInfo_t pinfo[FD_NUMPART]; /* fdisk
partitions */
} DiskParts_t;
How is the pinfo[FD_NUMPART] array ordered? Is it ordered by partition ID or by
physical partition order on the disk?
--------------------------------------------------------------------------------------
typedef struct {
int partitionId; /* fdisk id (1-4) */
int partitionOrder; /* Order in the disk */
int partitionType; /* Solaris/linux swap/X86boot */
om_content_type_t contentType; /* Solaris/Linux */
long partitionSize; /* Size in GB */
boolean_t active; /* Is the partition active */
} PartitionInfo_t;
There is no indication of of where the partition offset starts or ends on the
disk. It forces us to
assume that partition at order 0 begins at offset 0 and, partition at order 1
begins immediately
after where partition at order 0 ends and so on. This seems like a dangerous
assumption.
We discussed this briefly during the work week and about how the GUI would
handle it. I believe
we said the GUI, due to it's design would not support it (it doesn't convey
start and end points of
partitions to the user) and so it would issue a warning and force a destructive
repartitioning of the disk.
But from the data modelling perspective, partition start and end offsets seem
like important data to capture.
Thanks,
Niall.
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