ZFS is a modern filesystem originally developed by Sun Microsystems and licensed under the CDDL. An open-source fork of ZFS can be found at http://open-zfs.org/ , which is supported by ZFSonlinux.org, illumos.org and ZFS developers in the FreeBSD & MacOSX communities.

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3
votes
4answers
11k views

Disabling RAID feature on HP Smart Array P400

I'm planning to use ZFS on my system (HP ML370 G5, Smart Array P400, 8 SAS disk). I want ZFS to manage all disks individually, so it can utilize better scheduling (i.e. I want to use software RAID ...
2
votes
1answer
49 views

Choosing a zpool size?

Is there a rule of thumb when to create a new zpool instead of expanding the current? Right now I have 100TB and can either expand with another 100TB or create an extra.
9
votes
2answers
374 views

Are consumer class hard disks okay for zfs?

I just recently bought a new server an HP DL380 G6. I replaced the stock smart array p410 controller with an LSI 9211-8i. My plan is use ZFS as the underlying storage for XEN which will run on the ...
3
votes
1answer
327 views

ZFS on Linux/Ubuntu: Help importing a zpool after Ubuntu upgrade from 13.04 to 13.10, device IDs have changed

I have updated Ubuntu from version 13.04 to version 13.10, only to discover that the SATA disks IDs have changed, and my ZFS pool now fails. On new Ubuntu 13.10 the disk IDs are now ata-* instead of ...
0
votes
1answer
147 views

Debian KVM and location for vm images different than /var/lib/libvirt/images

I have defined storage pool for VMs on ZFS: virsh # pool-dumpxml zfs <pool type='dir'> <name>zfs</name> <uuid>b2fba550-467f-8133-dee8-44ada7d0a807</uuid> ...
2
votes
1answer
47 views

Is in-memory write-cache and ZIL data both written through TXG commits?

ZFS nowadays has an interval of 5 seconds for doing TXG (Transaction Group Commits) of the in-memory write-cache.. How and after how long is ZIL data committed to the rotational media from say, an SSD ...
2
votes
2answers
129 views

zfs regular read pauses

We have a zfs file system running on openindiana with an almost purely read-only workload. Recently we have found that the io is blocked or pauses every 1 minute for around 2-3 seconds. Does anyone ...
1
vote
2answers
54 views

Can you add a different size RAIDZ1 to an exists zpool?

For example, I have a 4x2TB RaidZ1 set up right now, but I would like to add only a 3X4TB RaidZ1 in addition to it. Is there a way to do this with zdevs/another Zpool? Thanks
1
vote
1answer
68 views

Why is my RAIDZ2 pool larger than the expected size calculation?

I'm building a RAIDZ2 ZFS system, using Ubuntu 13.10 as a base system, and zfsonlinux's packages, having 6 disks dedicated to the pool data and a couple of SSD partitions to do ZIL log and L2ARC ...
2
votes
1answer
690 views

HP MDS 600 compatibility questions

I've bought a used HP MDS 600 to use as JBOD to a ZFS filesystem. Originally I just assumed that it was a pretty 'dumb' box and I'd be able to use a SAS card like the 16-port LSI one, and most any ...
1
vote
1answer
80 views

SAS IT Mode controllers and SAS Expanders

Lots of semi-related posts, but none that address this scenario. I picked up an LSI SAS1064E-IR based HP Controller. I flashed it with an -IT firmware, and things look somewhat ok. Except that I ...
9
votes
6answers
7k views

Is bit rot on hard drives a real problem? What can be done about it?

A friend is talking with me about the problem of bit rot - bits on drives randomly flipping, corrupting data. Incredibly rare, but with enough time it could be a problem, and it's impossible to ...
3
votes
1answer
122 views

FreeBSD 9.2 shows SATA3 drives as SATA2

I'm running FreeBSD 9.2 on an Intel S2600GZ server board with 4 Intel SSDs. Both the server board as well as the disks are SATA3 capable. However, FreeBSD seems to think they are SATA2. Nowhere in ...
1
vote
1answer
30 views

Prevent NexentaStor analytics page from timing out

NexentaStor has a handy profiling interface that serves as a front to certain dtrace scripts. It's handy for monitoring realtime IOPS or I/O throughput of the appliance. Unfortunately, this interface ...
4
votes
1answer
168 views

ZFS: bringing a disk online in an unavailable pool

I have a home server using FreeBSD and ZFS that has worked well for the last 5 years, and on several occasions I have successfully replace faulty disks. However, today a minor disaster has happened, ...
17
votes
1answer
393 views

Why are all the zpools named “tank”?

In practically every example of ZFS usage that I've seen online (including several questions here), the zpool is named "tank". Why? Is there some sort of significance to the name or is it just that ...
8
votes
5answers
501 views

ZFS best practices with hardware RAID

If one happens to have some server-grade hardware at ones disposal, is it ever advisable to run ZFS on top of a hardware-based RAID1 or some such? Should one turn off the hardware-based RAID, and run ...
1
vote
2answers
116 views

SmartOS using ZFS and guest filesystems [closed]

If I do something like RAIDZ2 with 10 or so disks, then on guest operating systems, if I use a filesystem like ext3/4, will the guest filesystem be as safe as if it were also using ZFS? The reason I ...
2
votes
1answer
343 views

Disk replace breaks disk naming convention in zpool

After replacing two broken disks in my RAID-Z2 pool, the output of zpool status looks strange. The disks are addressed with their full path and also seem to contain 'slices', which all other disk ...
1
vote
0answers
67 views

NexentaStor 3.1.5-GA (community ed) won't boot from a CD

I can boot from 3.1.5-GA ISO into a VirtualBox VM. But when I boot from a bootable CD, it stops at "Grub Stage2", and then drops me into a grub rescue shell after a few seconds.. I know very well how ...
4
votes
2answers
1k views

Ubuntu cp -p on mounted ZFS pool

On my Ubuntu server, I have several automounted zfs pools. The problem that I have, is that when I try to copy a file while preserving permissions, I get the following error: cp: preserving ...
2
votes
1answer
223 views

How often should I defrag ZFS pools?

I ZFS scrub once a month which takes ~24 hours for the 72TB. For what I can find about how often I should scrub is: very busy pools, once per week not so busy pools, once per month or run a scrub, ...
1
vote
1answer
113 views

ZFS: SAS v SATA - does it matter?

I understand from NEC's white paper, Silent data corruption in disk arrays, that: some SAS drives should have a "T10-DIF" feature to detect silent data corruption; whereas "There is no standard for ...
5
votes
2answers
720 views

ZFS performance: do I need to keep free space in a pool or a file system?

I know that the performance of ZFS heavily depends on the amount of free space: Keep pool space under 80% utilization to maintain pool performance. Currently, pool performance can degrade when a ...
1
vote
2answers
117 views

size the write cache ZFS

I would like to add a write cache to my Nexenta. I thought about using 2 SSDs in mirror with a third disc in spare. The problem is: How do I calculate the size of my array to maximize the investment ...
0
votes
0answers
102 views

ZFS destroy aborted - how to get rid of snapshot?

I've got a problem with one of my FreeNAS 8 boxes. I was deleting some snapshots with zfs destroy when unfortunatelly my PC crashed and therefore killed the SSH-connection while a snapshot destroyment ...
0
votes
1answer
122 views

zfs: zpool space map thrashing - ever fixed?

For zpools which are rather full and/or very fragmented I use to enable metaslab debugging (echo metaslab_debug/W1 | mdb -kw) to avoid space map thrashing and the resulting severe write performance ...
-1
votes
2answers
101 views

Can I remove a vdev from a ZFS pool by rolling back? [closed]

A curiosity related question: Can a VDEV be removed from a ZFS pool by undoing the last pool transactions (zpool import -F) or rolling back to an earlier snapshot?
1
vote
0answers
262 views

ZFS Recover from Faulted Pool State

I have a six disk ZFS raidz1 pool and had a recent failure requiring a disk replacement. No problem normally, but this time my server hardware died before I could do the replacement (but after and ...
0
votes
1answer
343 views

Netatalk 3.0.1 disconnects with Bad file descriptor on FreeBSD

I am having trouble with my netatalk server 3.0.1 on FreeBSD-9.1 RELEASE. Netatalk was installed from the ports collection and is sharing some directories over the network. Update also netatalk ...
1
vote
3answers
2k views

Converting NTFS to ZFS (or other)

Are there any benefits of converting HDDs that are running NTFS on a Linux machine to ZFS? Is there a way to do such conversion in Linux without losing the data? What about the stability of ZFS on ...
2
votes
2answers
229 views

iSCSI: LUNs per target?

My question relates specifically to ZFS/COMSTAR but I assume is generally applicable to any iSCSI system: Should one prefer to create a target for every LUN that you want to expose? Or is it good ...
13
votes
6answers
2k views

recommendations for efficient offsite remote backup solution of vm's

I am looking for recommendations for backing up my current 6 vm's(and soon to grow to up to 20). Currently I am running a two node proxmox cluster(which is a debian base using kvm for virtualization ...
2
votes
1answer
287 views

Using ZFS or XFS on a Xen guest running Linux

Background: I'm investigating the viability of using a filesystem other than ext3/4, with the ability to run snapshots for backup and rollback purposes. The servers under consideration are mailbox ...
3
votes
1answer
61 views

ZRAID1 pool size bigger than expected

I have 3x 4TB drives for a ZRAID1 config (single parity drive) After running zpool create data zraid1 sdb sdc sdd I have a volume that's 10.9T in size, which is what I would expect from a stripe ...
4
votes
1answer
143 views

Is there a way to limit the network bandwidth / filesystem use per user over NFS on a Solaris 10 file server?

We have a large file server running on Solaris 10 and about 200 computing nodes running on Ubuntu. The nodes access the file server over NFS. The load gets larger and larger over time. Is there a way ...
1
vote
1answer
207 views

How to Set up Amazon EC2 with Nexenta OS?

I want to use Nexenta os for testing purpose and really want to test it out over aws ec2. I couldnot find any Nexenta os ami's. So, i was wondering if there's any way to set up Nexenta os on aws ec2 ...
-4
votes
2answers
189 views

Hardware RAID0: what happens when a drive fails?

With a hardware-based RAID0, what happens when a drive fails? For example, on brand name servers like HP DL120G7 with HP P410, when running FreeBSD on a zfs with a zpool mirror, or DragonFly BSD with ...
4
votes
1answer
2k views

How to NFSv4 share a ZFS file system on FreeBSD?

Using FreeBSD 9, and created a ZFS file system like so zfs create tank/project1 zfs set sharenfs=on tank/project1 There are many howto's on setting up NFSv3 on FreeBSD on the net, but I can't find ...
0
votes
2answers
207 views

ZFS: 3 devices: what's the difference between mirror and raidz2?

It would seem like with 3 devices, it's possible to configure a ZFS pool with either mirror or raidz2 mode. What's the difference in performance and reliability? (In regards to reliability, I'm ...
2
votes
3answers
96 views

zfs on a single device: what happens when a file is corrupted?

It is written everywhere that ZFS is helpful even if you only have one physical device, because it will tell you about data corruption due to bit decay and such. However, can it actually address such ...
0
votes
0answers
29 views

OSX and Windows networking protocol for ZFS NAS?

I am looking to build a NAS that will be accessible by roughly 10 users simultaneously. The users' workstations are a combination of OSX and Windows 7 and are connected via a 1gbE LAN. They will be ...
0
votes
0answers
25 views

Collect statistics about use of iscsi targets

We're using iscsi (open-isci) to access volumes stored on a ZFS server from virtual machines and on high load we'd like to identify which virtual machines is pound away at our file system. We ...
3
votes
2answers
457 views

Can XFS or GlusterFS replace my ZFS needs?

Right now I have a FreeBSD hosts with ZFS and NFSv4. It is replicated to another FreeBSD box for backup purposes. The ZFS features that are important to me are software RAID6 snapshots, or some ...
2
votes
2answers
251 views

recursively mounting ZFS filesystems?

I'm aware this more of a beginners question, but manpages, google and FreeBSD Handbook provided no solution. I'm using ZFS Version 28 on a 8.2 Stable FreeBSD and my problem is the following: When I ...
7
votes
5answers
2k views

Where is the central ZFS website now?

Oracle dumped OpenSolaris in Fall 2010, and it is unclear if Oracle will continue to publicly release updates to ZFS, except maybe after they release their next major version of Solaris. FreeBSD now ...
11
votes
1answer
291 views

Force update checksum on zfs?

I recently changed the checksum property on one of my non-duplicated zfs filesystems to sha256 from on (fletcher4) to better support the sending of duplicated replication steams, as in this command ...
1
vote
1answer
59 views

Replacing a recovered hard disk in a ZFS pool

I have a pool that is in UNAVAL status (" One or more devices could not be opened. There are insufficient replicas for the pool to continue functioning.") due to a recent disk failure. I'm planning ...
2
votes
1answer
144 views

What kind of “volume/storage management” has the largest support/feature set these days? [closed]

(DISCLAIMER: This is "time bound" as probably every other question, I just point it out now instead of implicating it) part of reviewing a few basic decisions for our infrastructure is once again the ...
1
vote
2answers
152 views

Increase space of ZFS pool over iSCSI SAN, online

I have an iSCSI volume of 96GB on SAN, which has ZFS pool implemented on it. i have resized the size of SAN volume from 96 to 120GB, but the zpool list only shows the old space (96GB). how to achieve ...