installing an OS onto a flash drive

Discuss the security implications of the various flavors of linux and unix

Re: installing an OS onto a flash drive

Post by thetan on Wed Nov 03, 2010 11:06 pm
([msg=48524]see Re: installing an OS onto a flash drive[/msg])

In terms of SSD hardware failure with modern devices, the software (filesystem) is usually to blame just as much as the hardware is. The problem with SSDs up until a couple years ago, was that all the common filesystems weren't "SSD aware".

An SSD is such a dramatic hardware paradigm compared to traditional HDDs, that using older filesystems on them is borderline retarded.

SSD performance benefits from data fragmentation, while data fragmentation could be one of the most detrimental things in terms of HDD performance. So using an FS that optimizes for data defragmentation on an SSD is basically a waste of resources while using an FS that has no data defragmentation algorithms on an HDD could be absolutely crippling.

In older FSs that were tailored to HDDs, in place writes were optimal for performance, while in newer generation FSs versioning (implemented with delta computation and rebasing), snapshotting (implemented with versioning), and mirroring (implemented with snapshotting and COW (copy on write)). All 3 of these algorithms avoid in place updates, using them only minimally and spreads writes over the entire medium far more effeciently. Even if an SSD aware FS doesn't implement these three systems, algorithms can usually be found to optimize the spreading of writes.

If you're using an FS thats designed for and optimized for rotating media on an SSD, then you have no right complaining about SSD life span, becuase the failure isn't SSD lifespan, the failure is your ignorance.

Notable SSD aware FSs:
  • ZFS - you can only get kernel support for it in Open/Solaris and FreeBSD and it's one of my favourite universal FSs (it's more then an FS tbh) was a product of Sun Microsystems, acquired by Oracle
  • BtrFS - This was meant to be the linux competitor to ZFS, it was developed by Oracle to compete with ZFS. This filesystem has never been released as stable and remains experimental, yet fairly stable in all my test cases and included as an install option in archlinux
  • NILFS - A filesystem that depends heavily on COW in an append only matter, check this article out

Less interesting SSD Aware FSs derived or inspired by JFFS2:
  • LogFS
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Re: installing an OS onto a flash drive

Post by fashizzlepop on Sun Nov 07, 2010 11:32 pm
([msg=48714]see Re: installing an OS onto a flash drive[/msg])

Praise all-amazing Thetan!!!

I just want to thank you for your posts... always very well written and incredibly informational.

Also wanted to add:
The glass is neither half-full nor half-empty; it's merely twice as big as it needs to be.
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Re: installing an OS onto a flash drive

Post by astromech_kuhns on Thu Nov 18, 2010 8:41 am
([msg=49072]see Re: installing an OS onto a flash drive[/msg])

i did not know that it would degrade the life of my flash drive. good thing i have not got around to doing it.

Thetan, good post and very informative. i dont think i will install a OS onto it. i made it a multi pass instead. :ugeek:
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