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.

learn more… | top users | synonyms

2
votes
1answer
2k views

Is it possible to change zfs raid-z1 to raid-z2 or raid-z3 on freenas?

I have a running freenas zfs on raid-z1. For safety i though of increasing parity. Enough spare space is available. Is it possible to upgrade a zfs raid-z1 to raid-z2 or raid-z3? thx for your help
2
votes
2answers
299 views

Why does zfs fail to cache this workload when “normal” filesystems cache it completely?

Update: because recordsize defaults to 128k, the amount of data read by the test program is much larger than the ARC on an 8GB system and still slightly larger than the ARC on a 16GB system. Reducing ...
-1
votes
1answer
578 views

ZFS checksum errors: what files are affected?

Here is a zfs pool with checksum errors: NAME STATE READ WRITE CKSUM pool0 ONLINE 0 0 42 c1t1d0 ONLINE 0 0 30 c1t2d0 ONLINE ...
0
votes
1answer
105 views

Samba intermittently timing out on writes to a ZFS share

I'm experiencing an odd problem on a file server intermittently failing when writing files. The problem occurs when I try to write a number of files from a (Windows 7) client at once. ...
0
votes
0answers
449 views

FreeNAS, ZFS, OS X, can't get write access

I have a OS X. I configured server, based on FreeNAS. Setup sharing trough AFP service. Set all permissions for read-write access for users and groups. I do all the same things for one UFS drive and ...
-1
votes
1answer
791 views

zpool import with missing device

I had two geli-encrypted partitions on separate disk in a zpool as simple disks (no raid*). I didn't want redundancy for all files, only for some selected datasets (for which I set copies=2). Now one ...
1
vote
2answers
520 views

How to check that all ZFS snapshots within a pool are without holds before destroying that pool

Question Already I can check each snapshot of a filesystem individually, manually. I would prefer to check all at once (all with a single command or script). Please: can that be done with a ...
1
vote
4answers
1k views

NFS IO priority on ZFS/Solaris

I've got a Nexenta/ZFS NAS that I'm using as an NFS backing store for a small VMware vSphere farm. At the moment I have 9x1TB disks all mirrored (last disk is configured as a write log device). The ...
4
votes
3answers
3k views

When using thin-provisioning with ZFS, how do you make sure you don't run out of physical disk space?

Forgive me if this seems like a fundamental question, but I couldn't really find anything concrete on Google, and I'm not a system administrator by trade. We are setting up a SAN at our office using ...
6
votes
2answers
514 views

What to call ZFS vdev that won't change?

I've got an Ubuntu (13.04) Desktop with ZFS support thanks to the PPA zfs-native/stable. Everything was working really well. I created a RAID-Z1 pool called inground with the following command: ...
3
votes
1answer
303 views

“zpool create” hangs indefinitely

I have a Solaris 11.1 machine which has some disks attached to it via an expander (LSISAS2X36) through an LSI 1068 controller. The setup used to work quite decently, but as I have added another batch ...
0
votes
0answers
155 views

zfs recovery after hardware failure

My ZFS storage hardware failed including the rpool disks. I installed a new server and tried to import use zfs import -f poolname. I am able to see the pool and the disk utilized. But I am not able to ...
6
votes
1answer
3k views

Clear a permanent ZFS error in a healthy pool

I scrubbed my pool today, and after the scrub finished, I noticed there was an error that corrupted a file. I didn't care about the file, so I deleted it. Unfortunately, the error remains (now ...
0
votes
1answer
2k views

Using SATA III SSDs for ZFS pools

I'm thinking of building a ZFS server optimized for random access (PostgreSQL database). I figured that I have 2 options: Use pools consisting of the Crucial M500 960 GB SATA III SSDs. Enterprise ...
5
votes
2answers
227 views

Is it Possible to Automatically Resilver a ZFS Array On Hotswap

I'm trying to learn about ZFS for a NAS I'm planning on building. I'm trying to understand if the following scenario would be possible to set up. Disclaimer: I know very little about ZFS, so forgive ...
2
votes
1answer
592 views

ZFS, NFS and Nexenta

Is this message familiar to someone ? zfs-clu-01a rpcmod: [ID 851375 kern.warning] WARNING: svc_cots_kdup no slots free zfs-clu-01a last message repeated 75220 times We have a lot of trouble ...
2
votes
0answers
232 views

ZFS on RedHat configuration

I have to set up a ZFS storage appliance (Oracle ZFS Storage ZS3-2) with NFSv4. The NFS is mounted on a Redhat 6.5 cluster, where the linux users are created (they don`t exist on the appliance). ...
5
votes
1answer
75 views

Is “zfs receive” an atomic operation?

Is zfs receive an atomic operation? Can a process read from or write to the receiving file system during the zfs receive operation? Can a process read any of the files in the incoming snapshot ...
4
votes
4answers
2k views

ZFS: Memory issues with dedup even though zdb -DD looks fine

I've been experimenting with ZFS on a machine with Ubuntu 12.10, 32GB RAM (non-ECC, production system will have ECC) and a 2x2TB Linux-managed RAID1 (will be moved to RAIDZ1 for production). I just ...
3
votes
1answer
88 views

Expanding ZFS on MDRaid?

I had a 4-disk mdraid of 8.12TB with zfsonlinux's ZFS: # zpool status pool: tank state: ONLINE scan: none requested config: NAME STATE READ WRITE CKSUM tank ...
-2
votes
2answers
416 views

Why does a failed ZFS disk still seem to work fine?

Two disks just failed in my zpool with read/write errors, so I took them out and inserted them in another host, created a zpool just with them, and filled the file system with dd if=/dev/zero ...
2
votes
1answer
292 views

XenServer Linux guest booting off iSCSI SAN (ZFS storage): Will a non-checksumming guest file system still be at risk?

We are storing files on FreeNAS 9.2 using ZFS. I love the data integrity claims made by ZFS, having randomly lost data in the past on servers using ext3, XFS, and ReiserFS that were not mistreated ...
2
votes
1answer
471 views

ZFS, NFS and user based quotas

I am using a ZFS storage (FreeNAS 9.1) with NFSv3. The NFS is mounted on Debian machine, where the linux users are created (they don`t exists on FreeNAS). How do I enable standard linux user based ...
4
votes
4answers
16k 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
54 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.
10
votes
2answers
952 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 ...
0
votes
1answer
568 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
112 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
182 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
148 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
406 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
959 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
268 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 ...
15
votes
6answers
9k 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
224 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
47 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 ...
5
votes
1answer
1k 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, ...
18
votes
1answer
681 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 ...
12
votes
5answers
4k 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
227 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
584 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
119 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 ...
5
votes
2answers
2k 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
2k 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, ...
6
votes
2answers
2k 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 ...
2
votes
2answers
812 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
1answer
489 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
395 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?
0
votes
1answer
508 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
3k 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 ...