Re: nested labels
On 2006 Sep 28 , at 01:08, Jeffrey Katz wrote: Adam Martin's discussion of nested partitions was very enlightening and useful. A nice thing about the approach is that it can be used on a dangerously dedicated hard drive. Well, it merely takes advantage of GEOM. You can even nest GPTs, and other things inside of BSD labels, and vice versa. The most important thing to keep in mind is that every time that you create a new device from partitioning a device, GEOM allows you to install partitioning tables on them, and make more devices from those. As can be seen from my absurd case. That said, there are many good reasons to avoid over-partitioning a drive. Data can become more difficult to organize, as various filesystems have limited space, and start filling up at different rates. Also, failures in the sectors that contain the partitioning tables will cause you to have great difficulty in reconstructing data, in the event of disc failures. Don't over abuse nested partitions. I like to keep a paper copy of the actual sizes of all the entities in my partition tables, and their offsets, and mountpoints. At least once, this knowledge has helped me recover from serious disc failure. With the advent of half-terabyte, and larger drives, we're nearing the upper bounds of 32-bit bounded filesystems, and partitioning tables. GPTs are supposedly able to handle larger volumes than 2TB. Keep an eye on the freebsd large disc project: http://www.freebsd.org/projects/bigdisk/index.html Cheers, -- Adam David Alan Martin ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
re: nested labels
Adam Martin's discussion of nested partitions was very enlightening and useful. A nice thing about the approach is that it can be used on a dangerously dedicated hard drive. Jeff ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: nested labels
Jeffery, On 2006 Sep 23 , at 16:15, J65nko wrote: On 9/21/06, Jeffrey Katz [EMAIL PROTECTED] wrote: I have hit the limit of 8 disklabels per slice. Supposedly, one can create lables within a label, thus overcoming this limit. I googled everything but could only find references to gpt-- nothing about nested labels or partitions. Can anyone detail the steps involved in setting up nested labels or partitions? There was some previous discussion in this thread about the merits of multiple partitions, and why one would need so many. I will not delve into a long discussion on this; suffice it to say that there are many valid reasons to create more than 8 partitions on one disc, and that these reasons are usually unique to the site in question. If a system administrator feels that he needs more division of storage, he likely has a good reason. A slice can have 8 labels, a disk can have 4 slices, so 4 x 8 labels = 32 labels Deduct from those 32 the reserved c and possibly b and you still have a lot to spare ;) Although, the above, using PC partitions with nested BSD labels within, is a viable solution, and can be used safely with sysinstall, to give you a nice GUI (well, not gui, but menu at least) to work with the partitions; the biggest problem here, and the reason I stopped doing this, is that you have to know in advance how many meta-partitions you want, and what sizes they are. For example, my old 160 GB disc was divided into a 32 GB and a remainder PC partition. Those each had 7 major partitions therein. (You can use partitions a and b for filesystems. It's just convention that we use a and b for root and swap.) As this can be done safely, and straightforward from the sysinstall program, I won't go into details here. What you can also do is use the bsdlabel(8) program on any slice. In FreeBSD, geom labels devices very simply, and sensibly. E.G.: /dev/ad0s1hs2def is a valid device name. Granted it is a very absurd case, but it illustrates how one can use it. In geom, any PC partitions are appended as sN where N is 1 thru 4 for primary partitions, and 5 thru (unknown?) for logical partitions. In the case of bsdlabel (disklabel) partitions, they receive letters a thru h. In the above example, the primary master disc's first primary partition has a bsdlabel, which the last partition of it has a PC partition table within, which has a primary partition in slot two. That nested PC partition has a BSD partition, with a partition in slot d, which has more BSD sub-labels. (Need I go on, with this pathological example?) In summary, you can make bsdlabels, inside of a partition (PC or BSD). This is done by just running bsdlabel -w on the partition in which you wish to create the sub-partitions. (bsdlabel -w /dev/ad0s1h, for example) You can then create unlimited levels of partitions. Remember that after running bsdlabel -w, you must run bsdlabel -e, to edit the partition. Do not forget to create filesystems in the partitions (newfs -UO2 for UFS 2 with softupdates.) As far as conventions, I prefer to put the extended partition into slot a, and set its type to unknown. In cases where slot a is taken by a root partition, I use slot h. I find that sticking to this convention helps keep me organized when employing this technique. Regards, -- Adam David Alan Martin ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: nested labels
On 9/23/06, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: On 9/21/06, Andrew Pantyukhin [EMAIL PROTECTED] wrote: On 9/21/06, Jeffrey Katz [EMAIL PROTECTED] wrote: I have hit the limit of 8 disklabels per slice. Supposedly, one can create lables within a label, thus overcoming this limit. I googled everything but could only find references to gpt-- nothing about nested labels or partitions. Can anyone detail the steps involved in setting up nested labels or partitions? You might want to have a look at glabel(8), or maybe gnop(8), or even http://wiki.freebsd.org/gvirstor And with file backed memory disks feeding from qemu nfs servers . . . Come on, geom is not that bad. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: nested labels
On 9/21/06, Jeffrey Katz [EMAIL PROTECTED] wrote: I have hit the limit of 8 disklabels per slice. Supposedly, one can create lables within a label, thus overcoming this limit. I googled everything but could only find references to gpt-- nothing about nested labels or partitions. Can anyone detail the steps involved in setting up nested labels or partitions? A slice can have 8 labels, a disk can have 4 slices, so 4 x 8 labels = 32 labels Deduct from those 32 the reserved c and possibly b and you still have a lot to spare ;) ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: nested labels
On 9/21/06, Andrew Pantyukhin [EMAIL PROTECTED] wrote: On 9/21/06, Jeffrey Katz [EMAIL PROTECTED] wrote: I have hit the limit of 8 disklabels per slice. Supposedly, one can create lables within a label, thus overcoming this limit. I googled everything but could only find references to gpt-- nothing about nested labels or partitions. Can anyone detail the steps involved in setting up nested labels or partitions? You might want to have a look at glabel(8), or maybe gnop(8), or even http://wiki.freebsd.org/gvirstor And with file backed memory disks feeding from qemu nfs servers . . . -- -- ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: nested labels
On 9/21/06, Jeffrey Katz [EMAIL PROTECTED] wrote: I have hit the limit of 8 disklabels per slice. Supposedly, one can create lables within a label, thus overcoming this limit. I googled everything but could only find references to gpt-- nothing about nested labels or partitions. Can anyone detail the steps involved in setting up nested labels or partitions? You might want to have a look at glabel(8), or maybe gnop(8), or even http://wiki.freebsd.org/gvirstor ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: nested labels
On 9/21/06, Jeffrey Katz [EMAIL PROTECTED] wrote: I have hit the limit of 8 disklabels per slice. Supposedly, one can create lables within a label, thus overcoming this limit. I googled everything but could only find references to gpt-- nothing about nested labels or partitions. Can anyone detail the steps involved in setting up nested labels or partitions? There was a discussion on hackers@ recently which mentioned nested labels. Have a search of the archives. Personally I wouldn't touch that solution with a 10ft pole. You explain far too little about *why* you have run out of partitions and what your current disk setup is like. Another option to consider is logical/extended slices (DOS partitions). Inside one of those you can create more FreeBSD slices. The only caveat is that I believe sysinstall will not recognise them so you are down to bsdlabelling them by hand (but you are with nested labels as well); or you can forget labelling them and just use each slice as a partition. Another solution: buy another disk. Slightly wasteful, but by far the easiest. --Alex ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
