let me be clear:

i lost a ext4 filesystem on a qnap nas.

that’s what i WILL NOT RECOMMEND EXT4 to you!

PLEASE STAY WITH EXT3 for the NEXT 5 YEARS UNTIL EXT4 WILL BECOME STABLE, EVEN IF IT IS SLOWER THAN EXT4… THE BOTTLENECK WILL BE THE LAN ANYWAY.

SAFETY OF YOUR FILES IS MORE IMPORTANT THAN SPEED.

SO I WOULD ALSO RECOMMEND YOU TO DO RAID1 (2x HDs, SAME SIZE) OR RAID6 (where 2x drives can fail with no dataloss but you will need 5HDs)

RAID6 IS NOT „BETTER“ THAN RAID1, IT CAN ONLY STORE MORE STUFF. But it seems like RAID1 is the only Raid-Level that is properly implemented? (!?!?!? http://www.zdnet.com/article/why-raid-6-stops-working-in-2019/ )

I think no matter in business or in private scenarios, RAID1 should be used in combination with a simple, reliable filesystem like ext3 and regular automatic filesystem checks.

In addition to this i would recommend backing your stuff up automatically via internet. But this is a different difficult topic which should be possible with rsync which is capable of transfering deltas even of larger files. (instead of re-transmitting the whole file, it transmits only the bits that have changed).

http://dwaves.de/2016/04/18/linux-automatic-filesystem-check-on-reboot-every-sunday/

MY RECOMMENDATION: WHO CARES IF THE NAS IS DOING A AUTOMATIC REBOOT AT SUNDAY 3 o’CLOCK IN THE MORNING AND CHECKING 2-3TB OF EXT3 FILESYSTEM? NO ONE!

SO WHO CARES ABOUT THE FILESYSTEM CHECK DELAY ON BOOT, IF IN RETURN, YOU WILL HAVE A RELIABLE FILESYSTEM.

RELIABILITY SHOULD BE THE TOP1 PRIORITY OF ANY FILESYSTEM.

MAYBE SPEED CAN BE SECOND, UNLESS YOU DO NOT CARE ABOUT DATA-LOSS. (temporary storage… but believe me… even a temporary storage contains important files that users feel very angry about if lost)

So what you SHOULD do is let your filesystem (no matter what system) be checked automatically and monthly/weekly.

some say:

„Home users can relax though. Home RAID is a bad idea: you are much better off with frequent disk-to-disk backups and an online backup like CrashPlan or Backblaze.“

i say… yes: Windows 7 in-build RAID1 functionality… failed me once (Win 7 Ultimate) but runs well on another machine.

The nasty thing: If it goes out of sync… it will not even notify you about that thing.

If the Win7-Software-Raid1 fails… it might be tricky to get it back working.

http://www.zdnet.com/article/why-raid-6-stops-working-in-2019/

ZFS

still a pretty new filesytem donated by Oracle.

It seems like they are using it on their Solaris OS which again runs on Sun’s SPARC systems.

So from database to hardware to filesystems – Sun and Oracle do it all.

I have no hands-on-experience with ZFS, but it seems to be a new concept, that is aiming at datacenter’s. (you will need at least 2GB of RAM to run it properly… otherwise it might CRASH!? A SSD is recommended as it seems to do „hybrid-drive“ stuff (combining RAM, SSD and SATA to one big drive… using RAM and SSD for caching and SATA for storage…  )

So it seems you should have „real“ professional server hardware if you use ZFS:

„#1 Yes you should be using ECC ram for using ZFS.. It’s in all the literature.. You do risk your whole pool if you have corruption without ECC..

#2 yes.. Motherboard.. CPU and RAM should be ECC..“

https://en.wikipedia.org/wiki/ECC_memory

https://forums.freenas.org/index.php?threads/need-help-to-pick-which-file-system-to-use.16489/

… QNAP NAS have no EEC… are these „prosumer“ devices, but not for critical data?

XFS

XFS was contributed to the Linux kernel by SGI and is one of the best filesystems for working with large volumes and large files.

XFS uses more RAM than other filesystems, but if you need to work with large files its performance there is well worth the penalty in memory usage.

XFS is not particularly ill-suited for desktop or laptop use, but really shines on a server that handles medium to

large size files all day long. Like ext3, XFS is a fully journaled filesystem.

I have heard that using XFS is a good way to f*** up your system if the power goes out while it is doing stuff.

http://arstechnica.com/civis/viewtopic.php?t=1169535

ext2

is the oldest filesystem included in Slackware Linux for storing data on hard disks. Compared to other filesystems, ext2 is simplistic. It is faster than most others for reading and writing data, but does not include any journaling capability. This means that after a hard crash, the filesystem must be exhaustively checked to discover and (hopefully) fix any errors.

ext3 <- recommended

ext3 is the younger cousin of ext2.

It was designed to replace ext2 in most situations and shares much the same code-base, but adds journaling support.

In fact, ext3 and ext2 are so much alike that it is possible to convert one to the other on the fly without lose of data.

ext3 enjoys a lot of popularity for these reasons.

There are many tools available for recovering data from this filesystem in the event of catastrophic hardware failure as well.

ext3 is a good general purpose filesystem with journaling support, but fails to perform as well as other journaling filesystems in specific cases.

One pitfall to ext3 is that the filesystem must still go through this exhaustive check every so often.

This is done when the filesystem is mounted, usually when the computer is booted, and causes an annoying delay.

MY RECOMMENDATION: WHO CARES IF THE NAS IS DOING A AUTOMATIC REBOOT AT SUNDAY 3 o’CLOCK IN THE MORNING AND CHECKING 2-3TB OF EXT3 FILESYSTEM? NO ONE!

SO WHO CARES ABOUT THE FILESYSTEM CHECK DELAY ON BOOT, IF IN RETURN, YOU WILL HAVE A RELIABLE FILESYSTEM.

RELIABILITY SHOULD BE THE TOP1 PRIORITY OF ANY FILESYSTEM.

MAYBE SPEED CAN BE SECOND, UNLESS YOU DO NOT CARE ABOUT DATA-LOSS. (temporary storage… but believe me… even a temporary storage contains important files that users feel very angry about if lost)

So what you SHOULD do is let your filesystem (no matter what system) be checked automatically and monthly/weekly.

or better: every time on boot by

touch /forcefsck

i never had any major issues with ext3. so stick with it 🙂

ext4

ext4 is the latest in the ext series of filesystems.

It was designed to build upon ext3 with new ideas on what filesystems should do.

While Slackware supports ext4, you should remember that this filesystem is still very new (particularly in file system terms) and is under heavy development.

If you require stability over performance, you may wish to use a different filesystem such as ext3.

With that said, ext4 does boast some major improvements over ext3 in the performance arena, but many people don’t yet trust it for stable use.

reiserfs

reiserfs is one of the oldest journaling filesystems for the Linux kernel and has been supported by Slackware for many years.

It is a very fast filesystem particularly well suited for storing, retrieving, and writing lots of small files.

Unfortunately there are few tools for recovering data should you experience a drive failure, and reiserfs partitions experience corruption more often than ext3.

JFS

JFS was contributed to the Linux kernel by IBM and is well known for its responsiveness even under extreme conditions.

It can span colossal volumes making it particularly well-suited for Network Attached Storage (NAS) devices.

JFS’s long history and thorough testing make it one of the most reliable journaling filesystems available for Linux.

vfat

Sometimes you may need to share data between Windows and Linux computers, but can’t transfer the files over a network. Instead you require a shared hard drive partition or a USB flash drive. The humble vfat filesystem is the best choice here since it is supported by the largest variety of operating systems. Unfortuantely, being a Microsoft designed filesystem, it does not store permissions in the same way as traditional Linux filesystems. This means that special options must be used to allow multiple users to access data on this filesystem.

swap

Unlike other filesystems which hold files and directories, swap partitions hold virtual memory. This is very useful as it prevents the system from crashing should all your RAM be consumed. Instead, the kernel copies portions of the RAM into swap and frees them up for other applications to use. Think of it as adding virtual memory to your computer, very slow virtual memory. swap is typically a fail-safe and shouldn’t be relied upon for continual use. Add more RAM to your system if you find yourself using lots of swap.

source: http://slackbook.org/beta/#id320403

should i raid1 my swap as well?

If you are using RAID1 you won’t lose half your swap, only one of the two mirrors. The worst case here is you’ll lose any performance benefit you might otherwise have gained. If you have two separate swap areas on the individual drives the kernel will use both in a fashion similar to RAID0 (if they have the same priority set) or JBOD (if priorities differ, using the top priority area until full then the next) so if one of the drives dies your system is likely to fall over as soon as any access to the swap area(s) is needed. This is why swap spaces usually live on the RAID1 volumes – it is simply safer and that is more important than performance usually.

http://serverfault.com/questions/195839/where-should-my-swap-partition-s-live-when-using-software-raid1-performance-lv

Speed:

ext4 still pretty fast (less seconds is better)

Overall, EXT4 is still performing the best „out of the box“ (with stock mount options) when testing the four leading Linux file-systems on a single SSD drive with the Linux 3.11 kernel. F2FS does have some wins, but in at least some tests it doesn’t appear to be always ensuring the data is syncing to the disk as with the other file-systems, which could potentially put your data at risk in case of a kernel issue or power loss. Coming up next will be tuning benchmarks of Btrfs and F2FS to see what further performance gains can be squeezed.

http://www.phoronix.com/scan.php?page=article&item=linux_311_filesystems&num=3

http://www.linux-magazine.com/Issues/2014/165/Choose-a-Filesystem/(language)/eng-US

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