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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534 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
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2answers
109 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
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1answer
340 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 ...
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0answers
165 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
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1answer
68 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 ...
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4answers
559 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
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1answer
63 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 ...
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2answers
248 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
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1answer
183 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
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1answer
195 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 ...
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4answers
13k 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
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1answer
53 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.
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2answers
590 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
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1answer
375 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
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1answer
76 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
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2answers
150 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 ...
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2answers
83 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
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1answer
141 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
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1answer
807 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
153 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 ...
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6answers
8k 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
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1answer
156 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
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1answer
41 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
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1answer
528 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
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1answer
462 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 ...
9
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5answers
1k 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 ...
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2answers
159 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
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1answer
423 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
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0answers
90 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 ...
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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 ...
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1answer
617 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, ...
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1answer
187 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 ...
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2answers
1k 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 ...
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2answers
386 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 ...
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0answers
207 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
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1answer
232 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 ...
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2answers
225 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?
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0answers
635 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
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1answer
426 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 ...
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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
563 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
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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
365 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
78 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
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1answer
213 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 ...
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1answer
250 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 ...
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2answers
246 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
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1answer
3k 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
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2answers
384 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
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3answers
105 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 ...