Questions tagged [block-device]
A data storage device that supports reading/writing data in fixed-size blocks, sectors, or clusters.
481 questions
3 votes
0 answers
55 views
Pitfalls of direct IO with block devices?
I'm building a database on top of io_uring and the NVMe API. I need a place to store seldomly used append like records (older parts of message queues, columnar tables that has been already aggregated, ...
- 185
7 votes
4 answers
2k views
Does the content of LUKS disks become encrypted again at unmount or at power-off
It is clear that when a LUKS disk is mounted and the password/key has been provided, anyone with direct access to the computer can access the files in decrypted form. I am wondering if unmounting the ...
- 71
1 vote
0 answers
56 views
How to use dm-mirror, or 'dm-raid raid1', with dmsetup only (no LVM automation)?
The goal is to create a mirror (aka raid1) device from two devices (to be mirrored), and (if needed) a third device that serves as the dirty region log / metadata / whatever. That, without using LVM ...
- 149
0 votes
1 answer
49 views
Listing block devices on unix 7.1.14
I need to access an array with SCSI drives (storage works, modelHC901) and it's attached to a server running Unix 7.1.1.4. How can I list all block devices on this system?
8 votes
2 answers
1k views
No media found on a USB flash drive - chances of reviving?
Context I was in class at my university, and there I needed to fetch some files from my 64GB USB drive to a local computer. When I plugged USB in... nothing happened, the computer did not recognize ...
- 199
5 votes
2 answers
487 views
How to get name of loop device that contains a LUKS-encrypted logical volume
In Ubuntu, I have mounted a raw disk .img file as a loop device that contains a LUKS encrypted LVM with an Ubuntu install on it. It is mounted like so: (output is from lsblk -o NAME,PKNAME,KNAME,...
- 327
0 votes
1 answer
109 views
Determine used space of a block device with no filesystem
How can I determine used space of a block device that has no filesystem on it? If it helps, such device is managed via lvm. I understand that the concept of "used space" on a device without ...
- 101
0 votes
2 answers
440 views
What is `BLKSECDISCARD`?
I've been trying to get a "clean" f2fs format on a WD SSD drive. But there is something that bugs me, and I cannot seem to find any specific details on it. When I format the SSD with f2fs: $ ...
- 3,928
1 vote
1 answer
120 views
Disconnected block device remains in /sys, is not seen as detected when re-connect
System is Linux Mint 21 based. My USBstick was receiving some files and after message "Do not disconnect" had disappeared I unplugged it. This time though waiting whirl remained in Disks GUI ...
- 1,501
3 votes
2 answers
513 views
How can I use lsblk to display all devices except my root/main "sda" device where my root filesystem is "/"?
I use LUKS (so my system is encrypted) and LVM. I don’t want sda displayed because that’s where my root filesystem lives, and it’s my root device. The solution should also work for systems without ...
- 10.2k
1 vote
1 answer
83 views
How to copy partition with trimming?
I want to clopy a partition between SSD devices. Normally I could do it simply with the "dd" or "buffer" commands. However, now that I have SSDs, I also would like to miss the ...
- 10.5k
6 votes
1 answer
2k views
how eMMC boot partitions work (/dev/mmcblk0boot0) and their handling in linux
i would like to fully understand the (special?) handling of eMMC boot partitions (in Linux). As far as i understand, eMMCs offer some kind of low level partitioning. There is a special meaning to (at ...
- 61
0 votes
1 answer
304 views
What is the minimal btrfs sector size?
I am thinking on using btrfs for a data volume with many small files. It is unclear, what the doc states about the minimal possible block size. It looks, they and we are on a very different edges of ...
- 10.5k
0 votes
0 answers
48 views
Does a block device driver's queue_rq handler need synchronization with only a single hardware queue?
Reading through this tutorial and this reference, I see that block device requests go through the hardware queue before being dispatched to the queue_rq handler. When writing a block device driver ...
- 359
1 vote
1 answer
344 views
Is there a way to change the block size of a disk partition without reformatting it?
I tried copying some browser cache files to a separate disk and although the free space was enough the disk run out of space because each small file used took up the minimum disk allocation space. Is ...
- 7,919