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Questions tagged [disk-utility]

Commonly used to refer to Disk Utility.app, an application included with OS X.

253 questions
166
votes
7 answers

Why is “/dev/rdisk” about 20 times faster than “/dev/disk” in Mac OS X

According to the rasbery pi documentation, You can load your OS to a flash card with either /dev/disk or /dev/rdisk. rdisk stands for raw disk. /dev/disk is a block level device, why would rdisk be 20 times faster? Using Mac OSX Note: In OS X…
spuder
  • 10,135
74
votes
5 answers

How do you format a 2 GB SD card to FAT32 (preferably with Disk Utility)?

I've been looking around for a way to do this for a while, but I haven't been able to find the answer. I need to format my 2 GB SD card to FAT-32, but I don't see the option in Disk Utility. If I select the SD drive (Apple SDXC Reader Media) and go…
Matt Reynolds
  • 880
43
votes
6 answers

Is it possible to check an external USB Drive health (SMART)?

Is it possible to check an external USB Drive health (SMART)?
user3109
24
votes
9 answers

Fix bad blocks on Mac hard disk

I have a hard disk that I scanned with TechTool and it reports one bad block. As far as I can tell, TechTool only scans and reports a failure. It doesn't fix anything. Back in the day, Norton Disk Doctor did the job of scanning and flagging…
Andrew Vit
  • 1,070
23
votes
11 answers

How can I resolve the error "MediaKit reports partition (map) too small"?

I am unable to expand my Mac's hard disk. diskutility reports this error: MediaKit reports partition (map) too small How can I resolve this?
dfd
  • 231
18
votes
5 answers

Equivalent of badblocks on Windows or DOS

Is there a utility in DOS or Windows that is as thorough as badblocks on Linux?
elliot s
  • 181
17
votes
2 answers

Shrink a .sparseimage

I have a .sparseimage that occupies 90GB of space on my hard drive despite only having 30GB of files in it. How can I reclaim the empty space used by the .sparseimage and compact the file?
squircle
  • 6,773
16
votes
3 answers

Difference between ISO, MDS & BIN/CUE disk image formats?

What is the difference between these major disk image formats? Are there any specific advantages / disadvantages for any of them?
Deepak Prakash
  • 342
14
votes
6 answers

Cannot resize OS X partition

I am trying to resize my existing Mac OS Extended partition on my Macbook to install Windows 7 (using steps similar to these), but when ever I go to apply the changes, I get this error: Partition failed Partition failed with the error: The…
Josh Hunt
  • 21,369
13
votes
1 answer

zpool: pool I/O is currently suspended

I'm using ZFS on OSX and I've zpool which is active and online: NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT WD_1TB 931G 280G 651G 30% 1.00x ONLINE - but I can't actually mount it. $ sudo zfs mount WD_1TB cannot open…
kenorb
  • 26,615
12
votes
1 answer

What is the equivalent of windirstat for Android for identifying space hogs

I have a Google Nexus 6 running Android 7.1.1. How can I find what is occupying the device's disk space ? It has a 32 GB disk but most of the time, I see only 300-400 MB free space, getting constant warnings. After deleting bunch of photographs and…
anjanbacchu
  • 1,457
10
votes
1 answer

diskutil rename error: "does not appear to be a valid volume name for its file system"

I'm trying to rename the volume name of a mounted ISO image using the command: diskutil rename /dev/disk15 TEST_DISK_2014_RENAMED I get the error: TEST_DISK_2014_RENAMED does not appear to be a valid volume name for its file system I tried…
hmj6jmh
  • 557
9
votes
1 answer

Create new partition on encrypted volume in OS X Lion

Updated: see below. I encrypted a 500 GB partition on an external 1TB drive on OS X Lion. The other 500 GB was not used yet and I want to create another partition on the external drive now. Disk utility will not let me do this and refers to the…
Tim
  • 1,752
9
votes
2 answers

How to restore from a sealed APFS volume when restore fails "because it has a broken seal"?

I have been researching this for many hours over the last week. A description of my research effort is at the end of this post. Disk Utility will not restore an APFS volume "because it has a broken seal," but the volume appears to be sealed. The…
timeSmith
  • 380
9
votes
1 answer

What is the relationship of await, r_await and w_await in iostat -x command?

I want to know the relationship of the await, r_await and w_await columns in the output from iostat -x. Below is an example output of an iostat I/O statistics. avg-cpu: %user %nice %system %iowait %steal %idle 7.55 0.01 5.70 …
user991704
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