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55

ZFS will give you advantages beyond software RAID. The command structure is very thoughtfully laid out, and intuitive. It's also got compression, snapshots, cloning, filesystem send/receive, and cache devices (those fancy new SSD drives) to speed up indexing meta-data. Compression: #zfs set compression=on filesystem/home It supports simple to create ...


38

I traced this issue back to a discussion about a commit to the XFS source tree from December 2010. The patch was introduced in Kernel 2.6.38 (and obviously, later backported into some popular Linux distribution kernels). The observed fluctuations in disk usage are a result of a new feature; XFS Dynamic Speculative EOF Preallocation. This is a move to ...


25

I've found XFS more well suited to extremely large filesystems with possibly many large files. I've had a functioning 3.6TB XFS filesystem for over 2 years now with no problems. Definately works better than ext3, etc at that size (especially when dealing with many large files and lots of I/O). What you get with ZFS is device pooling, striping and other ...


14

At what point does it make sense to depart from the OS-provided kernels and packages when the upstream maintainer has broken an important feature? "At the point where the vendor's kernel or packages are so horribly broken that they impact your business" is my general answer (coincidentally this is also about the point where I say it makes sense to start ...


13

using lvm snapshots and xfs on live filesystems is a recipe for disaster especially when using very large filesystems. I've been running exclusively on LVM2 and xfs for the last 6 years on my servers (at home even since zfs-fuse is just plain too slow)... However, I can no longer count the different failure modes I encountered when using snapshots. I've ...


13

No, you don't lose (nor gain) any space via adjusting RAID stripe size. Stripe size is about telling your RAID system how to portion data for I/O operations. How you look on the stripe size depends on RAID level. For parity-calculating RAIDs (4,5,6), a write smaller than a stripe size causes a read-modify-write cycle, because parity is always calculated ...


13

This was fixed (quietly) by Red Hat April 23, 2013 in RHEL kernel-2.6.32-358.6.1.el6 as part of the 6.4 errata updates...


12

You can make a backup, and then create a new smaller file system and restore. XFS cannot be shrunk (ref).


11

xfs_db has an option blocktrash which Trash randomly selected filesystem metadata blocks. Trashing occurs to randomly selected bits in the chosen blocks. This command is available only in debugging versions of xfs_db. It is useful for testing xfs_repair(8) and xfs_check(8). For example xfs_db -x -c blockget -c "blocktrash -s 512109 -n 1000" ...


11

♡ Hey there... I read this question as really being a problem with the FreeBSD NFS stack... ZFS works very well on the supported platforms. So much so, that I've moved most of my ZFS systems running Solaris and NexentaStor to Linux (RHEL/CentOS), thanks to the ZFS on Linux project. If you're using ZFS now, going to anything else is a step backwards. I'm ...


10

A couple additional things to think about. If a drive dies in a hardware RAID array regardless of the filesystem that's on top of it all the blocks on the device have to be rebuilt. Even the ones that didn't hold any data. ZFS on the other hand is the volume manager, the filesystem, and manages data redundancy and striping. So it can intelligently ...


10

XFS is pretty stable on its own. It's a mature filesystem. Mount/formatting options will really only impact performance. I set the allocation group count and the log size. My usual mkfs.xfs command string is: mkfs.xfs -f -L /partitionname -d agcount=64 -l size=128m,version=2 /dev/sdb1 My mount options for a system with a battery-backed RAID controller are: ...


10

Thank you for updating the post with more information. You're running on ProLiant systems, so there's a certain amount of work required to optimize your controller and I/O situation. Also, your XFS mounts are using the default options. Remember that you're using a different driver between these operating systems. The EL5 server has cciss, while the EL6 ...


9

XFS. JFS is basically dead/unmaintained now. Most/all of the XFS developers now work at Redhat and kernel support for XFS is available out of the box in RHEL 5.4.


8

Definitely go with OpenSolaris for your NAS. Lots of options there, and ZFS can't be beat. For virtualization, I can think of two options off the top of my head: Use VirtualBox on OpenSolaris. It's come a long way, and I recall seeing something about a web based management utility for managing headless guests. Ah, found it: VBoxWeb If you must use ...


8

ZFS is absolutely amazing. I am using it as my home file server for a 5 x 1 TB HD file server, and am also using it in production with almost 32 TB of hard drive space. It is fast, easy to use and contains some of the best protection against data corruption. We are using OpenSolaris on this server in particular because we wanted to have access to newer ...


8

Replaying a journal just means that the meta data gets put back to a clean state. It makes no guarantees on the data itself. This is true with any journaled file system, at least any that don't also do other tricks like COW (Copy On Write). So there is a potential for data corruption like this anytime a server gets shutdown uncleanly regardless of which ...


8

That's because Linux will allow you to create an XFS partition with large block-sizes, but can only mount an XFS partition that has a block size at or smaller than the memory page size. The memory block size set in all pre-compiled kernels of common distros is 4KB. Check it with getconf PAGE_SIZE. You can set it higher, but it requires compiling your own ...


7

Personally I use XFS all over the place (and it sound like that's for personal use). On an administrational decision it's not that important regarding size, with a 500GB disk you are nowhere near the limits of any filesystem (except FAT as David Schmitt pointed out). Do not consider NTFS, it may have read support but using NTFS under linux is just plain ...


7

Which OS are you planning on running? Or is that another part of the consideration? If you're running Solaris, XFS isn't even an option as far as I know. If you're not running Solaris, how are you planning on using ZFS? Support is limited on other platforms. If you're talking about a Linux server, I'd stick with Ext3 personally, if only because it receives ...


7

Truthfully there isn't much you can do to monitor the operational health of the filesystem itself. This thread explains the reasons why you can't perform an fsck-style check on a filesystem which is online as read/write. In part, you should trust that as a journalling filesystem, XFS is doing it's best to keep your data in good health. You may also take ...


7

I'd be tempted to stick with the default XFS block size of 4KB as it uses delayed allocation, so you'll see some very real efficiencies by using a smaller size. I certainly wouldn't worry about trying to match maildir file size to blocks anyway, you'll go insane, just let the FS do its job.


7

Use xargs -p or GNU parallel to speed things up considerably.


7

XFS and EL6 have fallen into an ugly state... I've abandoned XFS on EL6 systems for the time being due to several upstream features/changes slipping into the Red Hat kernel... This one was a surprise and caused some panic: Why are my XFS filesystems suddenly consuming more space and full of sparse files? Since November 2012, the XFS version shipping in ...


6

I'd go with ext3, hands down. I've heard that ext4 isn't that stable yet (don't shoot me if I'm wrong) it's got journalling, so unclean disconnects shouldn't be a problem. On ext3, there is always a portion of the disk hidden (5%). This is for when a root drive get's swamped, you can still log in at runlevel 1 to remove some data. On an external hard drive, ...


6

ZFS on linux is unfortunately still not a viable solution, even if you dismiss the issue of being a FUSE module (which can seriously cramp performance on certain workloads). It simply isn't complete enough. Also, I don't think there's a debugfs for ZFS on linux, which is a serious negative. debugfs is the traditional name for low level filesystem repair ...


6

I was able to resolve the issue in the following way: umount [the mountpoint] mount /dev/data_vg/data_lv -o inode64 [the mountpoint] Apparently, the default (32-bit inodes?) xfs will store all inodes in the first 1TB portion of the disk. This means that if the first 1TB is full, then you'll run into no space on disk errors even if it appears you have ...


6

ANY RAID 5 is sub-optimal, a 24-disk R5 array is just beyond stupid, I don't mean to be rude but most hardware array controllers won't let you create a 24 disk R5 array, think of how much data you may be losing without even knowing it. Also if you're doing any amount of any type of writing RAID5 or 6 aren't the way forward, in fact adding more spindles is ...


6

You could reword this as a non-shopping question, "How do I hook up a dozen SATA drives without using port multipliers or multiple PCI cards?" so I'll write an answer to that magical question: Buy a multi-ported SAS card and associated SAS 4x breakout cable (SFF-8087 MiniSAS to 4 SATA). 6gbps SAS2 is like SATA3 (6Gbps). Then use whatever motherboard you ...


5

Not a FS-oriented answer sorry but be aware that a number of disk controllers won't deal with >2TB LUNS/logical-disks - this can limit the way you organise your storage quite a bit. I just wanted you to be aware so you can check your system end-to-end to ensure it'll deal with 16TB throughout.



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