Storage
Storage Management on Windows XP
Contents
A basic disk is one that is divided into one or more partitions. When a partition or logical drive is formatted and assigned a drive letter it is called a volume. Basic disks contain only basic volumes. Dynamic disks manage volumes that can be simple, spanned (combine unequal partitions into one) or striped (combine equal partitions into one stripe set, improving write speeds). Dynamic disks allow volume management: there is no performance reason to use them. Volumes can be reformatted without rebooting. diskmgmt can also be used to manage disks on remote machines. Definitions:
Active Partition: partition from which system boots
System Partition: contains bootstrap files
Boot Partition: contains Windows system files
FAT16 drives allow a maximum file size of 2 GB and maximum partition size of 4 GB. FAT32 drives allow a maximum partition size of 32GB (although non-XP fdisk utilities can create larger partitions, up to 2TB). NTFS drives can be up to 16TB.
convert d: /fs:ntfs
Master File Table (MFT) is the index of all files and folders on the selected volume. MFT defaults to 12.5% of the partition size. To reserve space for MFT (and avoid defragmentation) during convert:
- defrag drive
- calculate size of MFT
- fsutil command to create contiguous placeholder file equal in size to MFT desired
- (fsutil file createnew c:\testfile.txt 1250000000
- run convert
- (convert c:\ /fs:ntfs /cvtarea:testfile.txt)
The convert utility in XP also applies default permissions to system folders (unlike its Win2000 predecessor)
Dynamic disks
Top BottomDynamic disks are incompatible with pre-Win2000 systems. Dynamic disk database stored in last 1MB of disk. Basic disks store partition table in 64-byte section of MBR. Dynamic disks allow spanned or striped volumes: Mirror and RAID5 options only available on .NET Server. Converting from dynamic disks to basic disks, implies that all data will be lost on the volumes. A simple volume on a Dynamic Disk is equivalent to a primary partition on a basic disk. To create a volume, run the 'New Volume Wizard' from diskmgr and select type required. Combining Volumes:
- you can extend only simple volumes or spanned volumes
- you cannot extend striped volumes
- you can only extend NTFS volumes
- you cannot extend a system or boot volume
- reducing an volume implies losing all data
In addition to assign drive letters, you can assign one or more drive paths to a primary partition, a logical drive or a simple volume on a dynamic disk. Use mounted disk to extend storage space on a volume and provide multiple access paths to folders. If a drive is mounted to a path in the root of a drive, it appears in explorer with a drive icon. If mounted elsewhere, it will appear with a normal folder icon. 'dir' command display mount points as <JUNCTION> instead of <DIR>. Tackle disk problems before tackling volume problems
Disk Status
Top Bottom| Status Message | Error | Solution |
|---|---|---|
| Online | ||
| Online (Errors) | system encountered errors reading or writing to the disk (dynamic disks only) | Right-click and choose re-activate disk. If errors continue check for disk damage |
| Offline | Disk was once available but is no longer accessible. Disk might be damaged or disconnected (dynamic disk only) | Check physical connections. Right-click and choose re-activate. If damage not repaired, delete all volumes and choose remove disk |
| Foreign | The disk was installed on another computer and has not yet been setup for use on this computer | Right-click and choose import foreign disk |
| Unreadable | All or part of the disk may be physically damaged, or dynamic disk database corrupted | Restart computer. Right-click and choose rescan disks. If still unreadable you may require 3rd party data recovery |
| Missing | Disk corrupted, disconnected or not power on | After reconnecting, right-click and choose reactivate |
| Not Initialised | Disk does not contain a signature | If new disk choose Initialise. If disk belongs to another OS (in use) do nothing |
| No Media | removable drive | Insert disk and choose rescan |
Volume Status
Top Bottom| Status Message | Error | Solution |
|---|---|---|
| Healthy | ||
| Healthy (At Risk) | Errors encountered reading or writing to underlying disk. Often caused by bad blocks | Right-click and reactivate disk. Persistent errors indicate a failing disk. Backup all data and run hardware diagnostics |
| Healthy (unknown partition) | Windows does not recognise some partitions (created by other OS or PC manufacturers utility partition) | If you are sure partition is not necessary, delete it |
| Initialising | Disk management cannot determine status because disk is initialising | Wait: drive status should appear eventually |
| Failed | The dynamic disk is damaged or the filesystem is corrupted | To repair a failed dynamic volume, check to see if disk is online. If not reactivate. Then reactivate volume. Check if disk is connected |
| Unknown | boot sector corrupted, no access to data | check for boot sector virus, use fixmbr |
When your system shuts down improperly, windows runs autocheck on all NTFS drives where disk write was in progress. Disk caching can exacerbate this. Turn off all disk caching, until you fix source of abnormal shut downs.
Disk Quotas
Top BottomDisk Quotas: track usage by ownership SIDs. Use Quota tab in the properties dialogue for a volume. Can be used to deny disk space or simply to send warnings to the eventlog. Quota entries button shows current usage. Quota limits cannot be set for members of the administrators group.
Autoplay: right-click a removable drive to access the autoplay tab
