Partition troubles on a GIANT storage server
in [Linux Hardware]
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From: Ignoramus11153 on 23 Jan 2008 13:22 We have a storage server with a 3ware RAID drive. It has a bunch of disks that together form a 5TB storage array. Linux sees that array as /dev/sdb. The capacity is 5 TB (as I said). fdisk sees it as follows: ### Disk /dev/sdb: 5249.9 GB, 5249921187840 bytes ### 255 heads, 63 sectors/track, 638266 cylinders ### Units = cylinders of 16065 * 512 = 8225280 bytes ### Disk identifier: 0xcf00cb1c ### ### Device Boot Start End Blocks Id System ### /dev/sdb1 1 267349 2147480811 5 Extended ### /dev/sdb5 1 267349 2147480779+ 83 Linux Which is the way I want. I formatted this disk with fdisk a while ago. There is one giant extended partition, and a almost the same size logical partition inside, holding Linux data. The device /dev/sdb5 is mounted on /data. However, df -k /data says: Filesystem 1K-blocks Used Available Use% Mounted on /dev/sdb5 2113784952 239323764 1767087152 12% /data The above is wrong (or at least is not the way I expect), as I expect 1K-blocks count to say 5 million instead of 2 million. This got worse as I continued looking. If I start gparted /dev/sdb, it tells me that the only partition is /dev/sdb1 (ignoring /dev/sdb5), which according to it occupies the whole array and is in use. Somehow gparted does not see /dev/sdb5 at all, I think. The same exact thing happens to QTParted. The server works fine. I am very worried that 1) I am using less than half of what is available and 2) that something wrong could heppen. Some clarification will be appreciated. i
From: Ignoramus11153 on 23 Jan 2008 13:25 Also fdisk says on top: WARNING: GPT (GUID Partition Table) detected on '/dev/sdb'! The util fdisk doesn't support GPT. Use GNU Parted.
From: stan on 23 Jan 2008 14:36 In comp.os.linux.misc Ignoramus11153 <ignoramus11153(a)nospam.11153.invalid> wrote: > We have a storage server with a 3ware RAID drive. > > Filesystem 1K-blocks Used Available Use% Mounted on > /dev/sdb5 2113784952 239323764 1767087152 12% /data > > The above is wrong (or at least is not the way I expect), as I expect > 1K-blocks count to say 5 million instead of 2 million. > > This got worse as I continued looking. If I start gparted /dev/sdb, it > tells me that the only partition is /dev/sdb1 (ignoring /dev/sdb5), > which according to it occupies the whole array and is in use. > Well- that's "billion" not "million", right? 2,113,784,952 In which case it looks suspiciously like 32-bit integer issues. It may well be that the "df" you are using is simply unable to report a value greater than 32-bits allows. Or maybe something totally different. Stan -- Stan Bischof ("stan" at the below domain) www.worldbadminton.com
From: Bill Marcum on 23 Jan 2008 14:28 ["Followup-To:" header set to comp.os.linux.misc.] On 2008-01-23, Ignoramus11153 <ignoramus11153(a)NOSPAM.11153.invalid> wrote: > > > We have a storage server with a 3ware RAID drive. > > It has a bunch of disks that together form a 5TB storage array. > > Linux sees that array as /dev/sdb. The capacity is 5 TB (as I said). > fdisk sees it as follows: > > ### Disk /dev/sdb: 5249.9 GB, 5249921187840 bytes > ### 255 heads, 63 sectors/track, 638266 cylinders > ### Units = cylinders of 16065 * 512 = 8225280 bytes > ### Disk identifier: 0xcf00cb1c > ### > ### Device Boot Start End Blocks Id System > ### /dev/sdb1 1 267349 2147480811 5 Extended > ### /dev/sdb5 1 267349 2147480779+ 83 Linux > > Which is the way I want. I formatted this disk with fdisk a while > ago. There is one giant extended partition, and a almost the same size > logical partition inside, holding Linux data. > > The device /dev/sdb5 is mounted on /data. However, df -k /data says: > > Filesystem 1K-blocks Used Available Use% Mounted on > /dev/sdb5 2113784952 239323764 1767087152 12% /data > > The above is wrong (or at least is not the way I expect), as I expect > 1K-blocks count to say 5 million instead of 2 million. > > This got worse as I continued looking. If I start gparted /dev/sdb, it > tells me that the only partition is /dev/sdb1 (ignoring /dev/sdb5), > which according to it occupies the whole array and is in use. > Does it show sdb1 as an extended partition? Perhaps you should back up your data, just in case, and create a logical partition with gparted. You might need to resize the filesystem to use the entire partition. > Somehow gparted does not see /dev/sdb5 at all, I think. > > The same exact thing happens to QTParted. > > The server works fine. > > I am very worried that 1) I am using less than half of what is > available and 2) that something wrong could heppen. > > Some clarification will be appreciated. > > i
From: Joshua Baker-LePain on 23 Jan 2008 18:42
On 2008-01-23, Ignoramus11153 <ignoramus11153(a)NOSPAM.11153.invalid> wrote: > > Linux sees that array as /dev/sdb. The capacity is 5 TB (as I said). > fdisk sees it as follows: > > ### Disk /dev/sdb: 5249.9 GB, 5249921187840 bytes > ### 255 heads, 63 sectors/track, 638266 cylinders > ### Units = cylinders of 16065 * 512 = 8225280 bytes > ### Disk identifier: 0xcf00cb1c > ### > ### Device Boot Start End Blocks Id System > ### /dev/sdb1 1 267349 2147480811 5 Extended > ### /dev/sdb5 1 267349 2147480779+ 83 Linux > > Which is the way I want. I formatted this disk with fdisk a while > ago. There is one giant extended partition, and a almost the same size > logical partition inside, holding Linux data. fdisk does not support a device that big. You must use parted. I also rather hope that you're using a GPT disklabel, as standard (msdos) ones also don't work on a device that large. > The device /dev/sdb5 is mounted on /data. However, df -k /data says: > > Filesystem 1K-blocks Used Available Use% Mounted on > /dev/sdb5 2113784952 239323764 1767087152 12% /data > > The above is wrong (or at least is not the way I expect), as I expect > 1K-blocks count to say 5 million instead of 2 million. Yep, it's wrong. The safest thing to do is backup the data somwhere else, recreate the partition (with parted), reformat, and *verify* before putting data on the system that everything is working correctly. As an aside, there's really no need to use an extended partition on a device you'll only have one partition on anyway. Just create one primary partition and format that. -- Joshua Baker-LePain Department of Biomedical Engineering Duke University |