Sponsored Content
Top Forums UNIX for Beginners Questions & Answers Should I use a CoW filesystem on my PC if I only wanted snapshot capabilities ? Post 303044797 by stomp on Wednesday 4th of March 2020 05:42:58 AM
Old 03-04-2020
Another comment:

A con against zfs is the inability to remove VDEVs. A VDEV is a subpart of a volume.

Example:

Say you have a data volume consisting of a single disk(=vdev, 1 TB). You decide to replace your vdev of a single disk with a raid-1 vdev(1 TB), since you want add redundancy to be safe in case of a disk crash. That's possible. Over the years, you add another 2 vdevs(2x2TB,2x4TB) with raid-1 arrays. So you then have 3 vdevs making up your volume consisting of 2 disks each with an overall capacity of 7 TB.

You now decide you want to increase your storage again and simultaneously reorganize your 3 x raid1(6 disks=>7 TB usable) to 1 x raidz2(5x6 TB =>18 TB usable) to be able to cope with more simulateous disk crashes(2 disk crashes without data loss here) and at the same time reduce the number of active disks(6->5).

With zfs this is only possible by reformatting, since device removal is not fully supported by now. So you have to copy all the data, which must be done offline. ZFS top level device removal is in development at the moment, but i expect some years to pass until even raidz vdevs can be removed.

With LVM you can just add the new underlying disks and remove the old disks. No problem. All is possible to be done online. Btrfs can do that to and is even flexible to do more advanced migrations.

And Here are some experience reports about btrfs and zfs from users:

ZFS Vs BTRFS : linux

Some not to long gone data loss stories about btrfs are also there. I assume the cause may be lacking knowledge about file system operation. But of course that's only a suspicion.

Last edited by stomp; 03-04-2020 at 06:52 AM..
 

9 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Unix Capabilities?

We are looking into buying a new software, billing software that is, and want to know if you can run that on the same UNIX server as another major software? Is there a limit to the different types of software Unix can run, or is it like windows where you can install as many as you like? ... (2 Replies)
Discussion started by: hoz
2 Replies

2. UNIX for Advanced & Expert Users

p570 Capabilities

Hi there. I've been tasked with making a new design for our Unix systems :eek: Now the question I have is; How many LPARs can a p570 hold WITHOUT using a VIO Server. Many Thanks Kees (1 Reply)
Discussion started by: KeesH
1 Replies

3. Red Hat

Adding capabilities to an RPM

Hi. I downloaded a package that could only be installed on RHEL5, and not 4 or 3, so I got the source in order to compile it on RHEL 3 so hopefully it will work on all versions. So I have the source for a working package, but when I build it in RHEL 3 and then try to install it in RHEL 5, it... (6 Replies)
Discussion started by: Boaz
6 Replies

4. Filesystems, Disks and Memory

Wanted: Geographically distributed filesystem solution

I'm looking for a means to ensure that servers in the two or three datacenters, connected in a ring via IP through two ISPs, can distribute load and/or replicate data among at least two SAN-class disk devices. I want to evaluate several solutions, and I'm open to solutions ranging from free,... (6 Replies)
Discussion started by: otheus
6 Replies

5. Solaris

Cannot use filesystem while sending a snapshot

I've got a Solaris 11 Express installed on my machine. I have created a raidz2 zpool named shares and a simple one-disc zpool named backup. I have made a script that would send a daily snapshot of shares to backup. I use these commands zfs snapshot shares@DDMMRRRRHHMM zfs send -i shares@....... (10 Replies)
Discussion started by: RychnD
10 Replies

6. UNIX for Advanced & Expert Users

Use of Capabilities

I wonder if anyone could assist with some problems I'm having with Linux Capabilities and their use when using the commands "nice" and "schedtool". I run a couple of PCs, one is an elderly AMD Sempron 2800+ (32-bit, 2GHz clock and 3GB memory) that is used as a family multimedia system running... (3 Replies)
Discussion started by: MikeGM
3 Replies

7. Linux

Broadcom under Fedora 18 (Spherical Cow)

So I'm having a problem getting a Broadcom BCM4312 wireless controller to work under the broadcom-wl module $uname Linux 3.8.11-200.fc18.x86_64 #1 SMP Wed May 1 19:44:27 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux lspci -v 05:00.0 Network controller: Broadcom Corporation BCM4312 802.11b/g... (2 Replies)
Discussion started by: Skrynesaver
2 Replies

8. UNIX for Advanced & Expert Users

Linux capabilities discussion

Hi I'm trying to compile my linux kernel with CONFIG_SECURITY_CAPABILITIES=y. any idea what this thing does ?? Also another question , If I compile the kernel that I'm currently using , what'll happen ? ~cheers (3 Replies)
Discussion started by: leghorn
3 Replies

9. What is on Your Mind?

Anybody want to talk about Dirty Cow?

Hi All, How worried is everyone about the Dirty Cow Linux exploit? Has anybody experienced attacks yet? From the research I've done it seems that the exploit is "reliable" (that is it works nearly every time on vulverable systems) which is not good news. We all believe that Unix/Linux... (3 Replies)
Discussion started by: hicksd8
3 Replies
vxvmconvert(1M) 														   vxvmconvert(1M)

NAME
vxvmconvert - convert LVM volume groups to VxVM disk groups SYNOPSIS
vxvmconvert DESCRIPTION
vxvmconvert is a menu-driven program to convert an HP Logical Volume Manger (LVM) configuration to a Veritas Volume Manager configuration. This man page is a brief overview of vxvmconvert. Refer to the Veritas Volume Manager Migration Guide for a detailed description before using the conversion procedure. The vxvmconvert script is interactive and prompts you for responses, supplying defaults where appropriate. There is a Help facility at every prompt. Enter a question mark (?) at a prompt to display a context-sensitive help message. With vxvmconvert you can identify LVM volume groups, list disks, analyze volume groups for conversion and complete the conversion of LVM volume groups to VxVM disk groups. LVM configurations are converted at the volume group level. All disks used in a volume group are converted together. You cannot use vxvm- convert to convert unused LVM disks (those not part of an LVM volume group) to VxVM disks. To convert unused LVM disks, use pvremove to take the disk out of LVM control, then initialize the disk for VxVM use by using vxdiskadm (see pvremove(1M) and vxdiskadm(1M) for more information). vxvmconvert changes disks within LVM volume groups to VxVM disks by replacing the areas of the disks used for LVM configuration information and with the equivalent VxVM volume configuration information. Portions of the disks used for user data, such as file systems and data- bases, are not affected by the conversion. The conversion process changes the names by which your system refers to the logical storage, so must be done offline. No applications can access data in the volume groups undergoing conversion. You must unmount file systems using those volumes and shut down any applications, such as databases, that might use the volumes directly. OPERATIONS
Analyze LVM Volume Groups for Conversion Use this operation to analyze one or more LVM volume groups for conversion to use by VxVM. The analysis checks for problems that can prevent the conversion from completing successfully. It calculates the space required to add volume group disks to a Volume Manager disk group. More than one volume group may be entered at the prompt. A grep-like pattern may be used to select multiple volume groups. See the ``Limitations in Conversion'' section in the Volume Manager Migration Guide for more information. Convert LVM Volume Groups to VxVM Converts one or more LVM volume groups to one or more VxVM disk groups. This adds the disks to a VxVM disk group and replaces existing LVM volumes with VxVM volumes. vxvmconvert prompts you to name the VxVM disk group that replaces the LVM volume group being converted. A default is suggested at the prompt. For example, if you are converting a volume group vg08, vxvmconvert renames it as dg08. See to the sections ``Dealing with New Logical Volume Names'' and ``Tailoring your VxVM Configuration'' in the Volume Manager Migration Guide for more information. Rollback from VxVM to LVM Rollback reverts VxVM disk groups to LVM volume groups. vxvmconvert provides a limited snapshot capability for the LVM metadata in a converted volume group. A snapshot is a simple protection method to use during conversion. Caution! Do not use this operation if the VxVM disk group was modified since the conversion. See to the section ``Restoring LVM Volume Groups and Disaster Recovery'' in the Volume Manager Migration Guide for more informa- tion. List Disk Information Displays information about the disks on a system. You can obtain detailed information about a disk by entering a specific disk device address. List LVM Volume Group Information Listvg displays a list of LVM volume groups. You can obtain detailed information about an LVM volume group at a specific disk device address. SEE ALSO
pvremove(1M), vgcfgbackup(1M), vgrestore(1M), vxdisk(1M), vxdiskadd(1M), vxdiskadm(1M), vxintro(1M) Veritas Volume Manager Migration Guide VxVM 5.0.31.1 24 Mar 2008 vxvmconvert(1M)
All times are GMT -4. The time now is 02:23 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy