how much of a performance impact full disk encryption (say, AES 256-bit) has on disk-related activities? On one particular project I'm involved in I am trying to weigh out security vs performance issues.
View 1 RepliesI have set up a Linux software RAID5 on three hard drives and want to encrypt it with cryptsetup/LUKS. My tests showed that the encryption leads to a massive performance decrease that I cannot explain. The RAID5 is able to write 187 MB/s [1] without encryption. With encryption on top of it, write speed is down to about 40 MB/s.
The RAID has a chunk size of 512K and a write intent bitmap. I used -c aes-xts-plain -s 512 --align-payload=2048 as the parameters for cryptsetup luksFormat, so the payload should be aligned to 2048 blocks of 512 bytes (i.e., 1MB). cryptsetup luksDump shows a payload offset of 4096. So I think the alignment is correct and fits to the RAID chunk size.
The CPU is not the bottleneck, as it has hardware support for AES (aesni_intel). If I write on another drive (an SSD with LVM) that is also encrypted, I do have a write speed of 150 MB/s. top shows that the CPU usage is indeed very low, only the RAID5 xor takes 14%.
I also tried putting a filesystem (ext4) directly on the unencrypted RAID so see if the layering is problem. The filesystem decreases the performance a little bit as expected, but by far not that much (write speed varying, but > 100 MB/s).
Summary:
Disks + RAID5: good
Disks + RAID5 + ext4: good
Disks + RAID5 + encryption: bad
SSD + encryption + LVM + ext4: good
The read performance is not affected by the encryption, it is 207 MB/s without and 205 MB/s with encryption (also showing that CPU power is not the problem). What can I do to improve the write performance of the encrypted RAID?
[1] All speed measurements were done with several runs of dd if=/dev/zero of=DEV bs=100M count=100 (i.e., writing 10G in blocks of 100M).
Edit: If this helps: I'm using Ubuntu 11.04 64bit with Linux 2.6.38. Edit2: The performance stays approximately the same if I pass a block size of 4KB, 1MB or 10MB to dd.
I've been using full disk encryption with luks on two Dell laptops for about 2.5 years. One is 64 bit Fedora (upgraded to 12), another is 32 bit Ubuntu (upgraded to 9.10), both were ext3, until recently.Over time, performance degraded substantially, especially on Fedora, which was put to a heavier use. That laptop has 4 Gb RAM, two 2.5 GHz T9300 CPUs, and 56 Gb of free space.
It was especially unbearable after a reboot. Programs like firefox and thunderbird would take close to a minute to start when ran for the first time after a boot. The login process was painfully slow, and some Gnome applets (e.g. Tomboy notes, keyboard layout switcher) would fail to load on the first login, with an error. I experienced this problem on both laptops with full encryption. I had to log out and relogin to make the applets appear. I tried various boot and mount options and was thinking about switching to ecryptfs (encrypted home).
I also use 3 desktops with no encryption and a netbook with ecryptfs on /home, which all work fine. All are Dell, 2 Ubuntu and 2 Fedora. The Gnome applets problem seems to be due to slowness of the installs with the full disk encryption. The last thing I tried is to migrate ext3 to ext4. I also converted /home, /usr, /opt to extents, following[URL].. That seemed to do the trick. Gnome applets now load fine on both laptops, and startup time is back to tolerable.
Is this a typical experience: ext3 performance degradation with time and a much better performance with full disk encryption once ext3 is migrated to ext4?
Which is the best whole hard disk encryption software for RHEL 4.6. Tried Truecrypt but was not success in making it work. First had issue with fuse version, then with glibc and etc.
View 5 Replies View Relatedi want to deactivate disk encryption. How can i do that?
View 1 Replies View RelatedBitlocker is a harddrive encryption data protection tool which comes with Windows Vista Ultimate and 7. Does anyone know an equivalent for Linux distros like Fedora and Ubuntu?
View 3 Replies View RelatedThe only reason why I don't use Linux (even though I prefer Linux over Windows, and can do everything faster and more efficiently) is because each time I try to learn about dm-crypt I give up.
Can someone point me in the right direction for full OTFE on Linux (like TrueCrypt)?
1. Fedora 14 has a user friendly disk encryption setup.However, there doesn't seem to be an option to change the encryption parameters during setup. Since I can handle the overhead, I would like to change the encryption algorithm and the key length for the default install.
2. I have created an additional encrypted drive (the entire HD) which claims to have its own encryption functionality (Seagate Constellation 1TB). Does Fedora use the built-in encryption mechanism by default? Is there any way to tell?
3. I can't seem to find any utility to tell me what the actual key size is for different HD's I have encrypted. "cryptsetup --help" seems to print out only the information for the default encrypted O/S which is the default 256 bit.
My problem is whether the -s option work when set to a 2,048 bit key length? Or, does it fall back to a 256 bit key length if it fails to do so? Or, does it automatically use the built-in encryption of the hardware? If the -s option doesn't work with a 2,048 bit key setting, can the kernel be recompiled to do so?
Quote: The importance of security should never be underestimated. The consequences of losing data can be disastrous for any organisation. For example, the loss of a single unencrypted laptop may have huge repercussions. This could include breaching data protection legislation with the risk of a significant fine, a loss in the confidence of an organisation, as well as the risk that sensitive data may fall into the hands of a competitor or third party with malicious intent.
View 1 Replies View RelatedI do know about cold boot attacks. But I ran across a couple of posts/websites that had me wonder if it is possible, without the passphrase, to just remove the encryption?
View 4 Replies View RelatedI would like to configure my Debian Jessie system in this way.
Two partitions:
1) /boot on /dev/sda1
2) everything else on /dev/sda2
I want to encrypt the second partition with LUKS. And then install over it a LVM volume. Inside the LVM volume i will create the / (root), /var, /opt and /home virtual partitions. In this way, i'll get asked only once for the password to decrypt all partitions. Because if i don't use LVM, then i'll get asked for the password for each encrypted partition.
I can follow and understand almost everything of this HOW-TO for Archlinux: [URL] ....
Only two passages are unclear to me:
1) Configuring mkinitcpio
I don't understand what i should do here in order to complete this. What should i do in Debian to configure "mkinitcpio"? what is the equivalent thing to do here?
I thought that the kernel would automatically recompile itself with all installed modules on the Debian system, once cryptosetup/LUKS or LVM2 get installed.
2) Configuring the boot loader
I don't understand what should i write in /etc/default/grub. Will GRUB automatically load the LUKS and LVM2 modules? Also, I don't think that i could boot the system in this way:
cryptdevice=/dev/sda2:LVM root=/dev/mapper/LVM-????
Actually the "root=" volume is the whole volume to mount as LVM. It isn't the final root partition.
With all the talk about disk encryption for Apple devices, I wanted to ask about how full disk encryption compares between debian linux and mac OS X. Is the code for debian linux fully available for people to inspect for flaws or backdoors? Apparently although part of the encryption code is available for OS X the full code for Filevault 2 is not public. What are the advantages and disadvantages of each method of encryption for each operating system?
View 8 Replies View RelatedI was trying to install Fedora 9 on my new laptop that came with Win XP. I have selected the option to wipe out all partition and create a default layout with the Encryption option selected. But that installation got stopped on the middle, therefore I have started the installation again. This time it asked for the encryption password as expected but don't know why, its not accepting my password. I am 100% sure that the password is correct but it is not allowing me to enter into the hard disk partition section.
My question is, how do I remove encryption from my hard disk? I don't need to preserve the data, I just need to use my hard disk again. Is there any boot CD that allow us to format encrypted disks without prompting for a password?
I have currently a file server that runs on Fedora 9, and all other PCs (mostly running Windows XP) access the file server via SAMBA. Everything works perfectly! However, lately a home invasion in my neighborhood got me thinking. If they take my file server, my data is not protected. So, I would like to implement the LUKS partition encryption (/home) which sits on a separate disk. However, I don't quite like the decryption process at boot time. In other words, I would like to wake up the file server (WOL) remotely, and when it's done booting, I would like to log-in using the other PCs and enter the passphrase remotely to decrypt /home. Is this possible using LUKS encryption (i.e., cryptsetup)? If not, what would be another alternative to what I am trying to do using a secure encryption (so that the data is safe from thieves)?
View 4 Replies View RelatedIs there any way to remove the whole disk encryption without reinstalling? I'm running Ubuntu 10.04.
View 2 Replies View RelatedIs there a way to change the password for the whole disk encryption?
View 2 Replies View RelatedFor some reason I can't find any documentation re: the algorithm(s) used by Ubuntu to encrypt the filesystem... Anyone know what it is?? AES?
View 2 Replies View RelatedI have a bunch of pictures that I thought I had backed up but as it turns out I didn't, the problem is I formatted the drive they were on.
It is a 1TB hard drive, and it was running Ubuntu 10.10 using full disk encryption from the alternate install CD. After formatting, I installed Ubuntu Server 10.10, also using full disk encryption.
I know the encryption key for both installs (and the keys in fact are the same).
I have turned off the machine, and have stopped writing to the disk. I am hoping because it is a 1TB drive, and I have only written over it with 2GB of data, that there is a chance I can recover the data.
I managed to get a cheap refurbed netbook recently (Samsung N150) and I'm wanting to put Ubuntu on it. As it's also likely to be used when travelling and have things like chat logs, photos, and other such things I'd like to do full disk encryption. Also I've been pointed towards 10.4 as apparently the 10.10 netbook desktop isn't to everyone's taste.
So I tried using unetbootin to make a bootable 10.4.1 i386 Alternate usb stick, which hit the problem of no cd drive. I found an item to add to the boot (cdrom-detect/try-usb=true) which got it a little further, but at a copying stage it threw an error saying it couldn't copy off the disc.
Finally I tried making a unetbootin of the mini iso (does mini even support full disk encryption?) but that seems to hang after selecting a mirror.
EDIT: Well it seems I was just impatient on the mini ISO and after a few minutes it's gone onto time-zone, though of course this could get rather tiresome without a local mirror, especially given this may go through more than one iteration.
Is there a way to install ubuntu 10.04 or 10.10 with full disk encryption? I read how to do it in the 8.0 version, was wondering if it is still possible?
View 4 Replies View Relatedany incompatibility for an encrypted disk (i.e. impossibility of reading the file system) among different versions of the same distro or among different Linux distros.
View 1 Replies View Relatedthis isn't really a security question, per se, so feel free to move. It is related to full disk LVM encryption though. Full disk didn't work for me with grub2 after running dd to a remote server, so I downgraded to grub1. No biggie. However, I have neither grub or grub2 as selected in Synaptic.Let's say I forget which I have installed. How would I determine what version of grub is installed at the moment. I'm assuming it's somehow installed on in the mbr but not on the OS. I didn't mean to do anything funky. Is that the normal setup? I'm deploying these systems to users and want to be able to troubleshoot issues in the future (hopefully that will not be needed!) grub --version does not work because it is not installed.
View 2 Replies View RelatedI encrypted a harddisk via Disk Utiluty. What alogythm is it encrypted by now? Is it safe? What should I be aware about?
View 7 Replies View RelatedI am investigating full disk encryption and have made a DD copy of the hard drive which has been encrypted, this DD file is stored on my computer for analysis.
First question is - Anyone know how i can access data in this DD file even though its been encrypted?
Second question - Is there a DD command where i can image the systems memory? I ask this because when a system is turned on, to get past the pre-boot authentication stage you need a password. From what i understand, this password will be passed in to ram when power is applied to the system. Making a copy of the memory will also copy the password?
I've been wanting to do this for a while and after upgrading some of my pc components I decided I would finally try to dual boot with full disk encryption on both windows 7 and Ubuntu 9.10. I managed to encrypt the windows drive with truecrypt and that worked. I installed Ubuntu 9.10 using the alternate cd and everything but /boot is in an encrypted LVM. Each OS is on a separate SATA drive the windows is on sda1 and ubuntu /boot is sdb1.
To setup the dual boot I started out following the tutorial [url] but its for XP and versions of ubuntu that use grub not grub 2. I ran dd as posted and saved the files it produced from truecrypt. I then ran into some problems with grub reinstallation so I simply reinstalled Ubuntu 9.10 from scratch again. This put grub 2 on the computer. I've managed to get it to add a Windows 7 option.
However, when the option is selected truecrypt comes up and says that the bootloader is corrupted and that I need to use the repair CD I burned before I encrypted the drive. My question is does anyone have any experience dual booting using Truecrypt on Windows 7 and LUKS/dm-crypt on Ubuntu 9.10 with grub 2? And how would I get the boot menu to work? I'd rather not reinstall but if I have to I have images from right before I encrypted so it wouldn't be the end of the world.
I would like to known whether I can configure the server to input the password for the encryption disk automatically during boot up.Is it possible
View 3 Replies View RelatedTo structure the layout of my partitions. I'm installing Windows 7, Backtrack 4 R2 and Ubuntu 10.10 Desktop on my laptop. I've got a 500 GB HDD named sda.
I've already installed Windows 7. It's my opinion that it's easiest to begin with Windows.
The partitions look like this right now:
The Windows installation is unencrypted and I want it to stay that way. It's only there in case my laptop gets stolen, I've installed various nasty things there.
The Backtrack 4 installation will also be given 100 GB space, I want it to be encrypted. The Ubuntu installation should get the rest of all the remaining space and preferably be encrypted but it's not 100% necessary.
How I should partition this? There's a limit on 4 primary partitions? How do I circumvent this? There should be one dedicated GRUB partition which will point to each of the installations own boot loaders?
Ubuntu 10.10 is dual booted but it is my primary OS.
Unfortunately it's on the outer edges of the disk in an extended partition.
This has always bugged me, with regards to read/write performance.
Do my concerns of reduced performance have any foundation? Should i bite the bullet and format the drive installing ubuntu first?
I ran the disk read benchmark and my read speeds were 100MB/Sec at the beginning of the test to just 55MB/Sec at the end. I have no idea if the position of the test has any bearing on the position of the disk or whether the speed recorded is affected by other factors such as the tests function or simulation.
I am running openSuse 11.2 (32-bit), my CPU only supports 32-bits. I have a hardware RAID device. My system has 4GB of RAM. When I configure my system to only use 3GB, 2GB, or even 1GB, using mem=1024M in grub, my RAID performance is much better then when letting my system use the default 4GB available.Can anyone explain to me why this is? Is there anything I can do, i.e. kernel configuration, that will help performance when running with all 4GB enabled?
View 5 Replies View RelatedI've just bought a 6-core Phenom with 16G of RAM. I use it primarily for compiling and video encoding (and occassional web/db). I'm finding all activities get disk-bound and I just can't keep all 6 cores fed. I'm buying an SSD raid to sit between the HDD and tmpfs. I want to setup a "layered" filesystem where reads are cached on tmpfs but writes safely go through to the SSD. I want files (or blocks) that haven't been read lately on the SSD to then be written back to a HDD using a compressed FS or block layer.
So basically reads:
- Check tmpfs
- Check SSD
- Check HD
And writes: - Straight to SSD (for safety), then tmpfs (for speed) And periodically, or when space gets low: - Move least frequently accessed files down one layer. I've seen a few projects of interest. CacheFS, cachefsd, bcache seem pretty close but I'm having trouble determining which are practical. bcache seems a little risky (early adoption), cachefs seems tied to specific network filesystems. There are "union" projects unionfs and aufs that let you mount filesystems over each other (USB device over a DVD usually) but both are distributed as a patch and I get the impression this sort of "transparent" mounting was going to become a kernel feature rather than a FS.
I know the kernel has a built-in disk cache but it doesn't seem to work well with compiling. I see a 20x speed improvement when I move my source files to tmpfs. I think it's because the standard buffers are dedicated to a specific process and compiling creates and destroys thousands of processes during a build (just guessing there). It looks like I really want those files precached.....