LVM You can extend a logical volume with "lvextend". You can also extend a filesystem, not sure if this is safe. Don't add a single disk. Create a RAID1 or RAID5, and add that. It may cost more, but can you risk data loss? I think I have read that there is a utility to add a disk to a RAID5. But I think it is not considered safe/stable. I can't find any info about it. -----Original Message----- From: linux-raid-owner@vger.kernel.org [mailto:linux-raid-owner@vger.kernel.org] On Behalf Of Maarten v d Berg Sent: Monday, January 12, 2004 4:21 AM To: linux-raid@vger.kernel.org Subject: Re: Extend raid 5 On Monday 12 January 2004 03:13, Mike Fedyk wrote: > On Mon, Jan 12, 2004 at 01:11:55AM +0100, buliwyf wrote: > > I have the following problem. > > I have set up a Linux Software Raid 5 with 4 160GB Disks. > > This works well. Now i run out of Disk Space and want to add another > > 160 GB Disk on the fly. Is this possible without loosing Data? > > No, the raid format splits the raid stripes sequencially between the drives > available in the array. So adding an extra online disk would really mess > up the formatting of the array, and therefore isn't allowed. > > There really isn't a way to get the redundancy of raid and the size > addition capabilities of LVM when you only want to add one disk. [...] > I'd suggest you add the drive as a seperate filesystem until you can setup > your array with lvm on raid. Hi Mike. I read about LVM some time ago and decided to use that as it seemed to solve my problem of the ever-growing data volume I need to store. However, after the initial setup I quickly dropped the LVM idea again since it only _seemed_ to solve my problem. As I understand it, LVM allows the addition of extra volumes but it does nothing at the level of the filesystem which resides on top. So in order to effectively grow my filesystem, which is the ultimate goal of course, I'd need to delete the current FS and make a new -bigger- one. And last time I checked this definitely kills your data. Otherwise, adding a 40 GB physical volume to a 120 GB raid5 / LVM set just gives me one 120 GB partition and [room for] another 40 GB partition. There is NO gain whatsoever using LVM here compared to when I would just have added a single 40GB disk all by itself without using LVM in the first place, is there ? This has always left me wondering. Did I miss something (except using some alpha FS-resize code...) ? Greetings, Maarten - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
