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Linux yang dipakai adalah Slackware 13.1. Namun demikian semua linux standar-pun bisa digunakan, asalkan sudah diinstal dengan base-package lengkap.
OS : Slackware 13.1 (base package console)
PC/Router : DELL Optiplex Pentium III 450 Mhz, 512MB SDRAM
Saya memiliki sebuah hardisk ATA kapasitas 120GB. Cuma ada 1 partisi di dalamnya (sdb1) yang diformat full dengan filesystem reiserfs.
root@arc:~# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/root 6353464 3212884 3140580 51% / tmpfs 188196 0 188196 0% /dev/shm /dev/sdb1 117214656 67196272 50018384 58% /mnt/hd root@arc:~# df -h Filesystem Size Used Avail Use% Mounted on /dev/root 6.1G 3.1G 3.0G 51% / tmpfs 184M 0 184M 0% /dev/shm /dev/sdb1 112G 65G 48G 58% /mnt/hd
Rencananya, disk ini akan di-split menjadi 2 partisi. Partisi kedua besarnya 30GB. Jadi, pertama akan di-ambil space-nya sebesar 30GB.
Skenario yang akan dilakukan ada 3 tahap:
1. check filesystem dengan reiserfsck
2. Me-resize filesystem dengan resize_reiserfs
3. Me-resize partisi dengan fdisk / cfdisk.
4. Membuat dan memformat partisi baru (sdb2)
STEP 1. Check Filesystem
1. Pastikan partisi yang akan diproses dalam posisi tidak di-mount.
root@arc:~# umount /mnt/hd/
2. eksekusi command reiserfsck
root@arc:~# reiserfsck /dev/sdb1 reiserfsck 3.6.21 (2009 www.namesys.com) ************************************************************* ** If you are using the latest reiserfsprogs and it fails ** ** please email bug reports to reiserfs-list@namesys.com, ** ** providing as much information as possible -- your ** ** hardware, kernel, patches, settings, all reiserfsck ** ** messages (including version), the reiserfsck logfile, ** ** check the syslog file for any related information. ** ** If you would like advice on using this program, support ** ** is available for $25 at www.namesys.com/support.html. ** ************************************************************* Will read-only check consistency of the filesystem on /dev/sdb1 Will put log info to 'stdout' Do you want to run this program?[N/Yes] (note need to type Yes if you do):Yes ########### reiserfsck --check started at Mon Dec 20 00:43:51 2010 ########### Replaying journal: Done. Reiserfs journal '/dev/sdb1' in blocks [18..8211]: 0 transactions replayed Checking internal tree.. finished Comparing bitmaps..finished Checking Semantic tree: finished No corruptions found There are on the filesystem: Leaves 21848 Internal nodes 150 Directories 26963 Other files 49887 Data block pointers 16798005 (29144 of them are zero) Safe links 0 ########### reiserfsck finished at Mon Dec 20 00:46:24 2010 ###########
3. Jika tidak ada errors, lanjut ke step berikutnya.
STEP 2. Resize Filesystem
Ekseskusi command resize_reiserfs, dengan parameter “-v” untuk verbose, “-s” untuk set resize, dan “-30G” untuk mengurangi besar partisi sebesar 30GB.
root@arc:~# resize_reiserfs -v -s -30G /dev/sdb1 resize_reiserfs 3.6.21 (2009 www.namesys.com) You are running BETA version of reiserfs shrinker. This version is only for testing or VERY CAREFUL use. Backup of you data is recommended. Do you want to continue? [y/N]:y Processing the tree: 0%....20%....40%....60%....80%....100% left 0, 6465 /sec nodes processed (moved): int 150 (30), leaves 21848 (4836), unfm 16768861 (4610953), total 16790859 (4615819). check for used blocks in truncated region ReiserFS report: blocksize 4096 block count 21440240 (29304560) free blocks 4640516 (12504596) bitmap block count 655 (895) Syncing..done resize_reiserfs: Resizing finished successfully. root@arc:~#
Proses ini akan memakan waktu lebih kurang 30 Menit, sesuai ukuran hardisk dan partisinya.
Jadi PASTIKAN LISTRIK anda JANGAN DAN TIDAK BOLEH MATI selama proses ini. Interupsi apapun beresiko membuat DATA HILANG.
Jika tidak ada error, sekarang coba mount kembali partisi sdb1 untuk melihat ukurannya:
root@arc:~# mount /dev/sdb1 /mnt/hd/ root@arc:~# df -h Filesystem Size Used Avail Use% Mounted on /dev/root 6.1G 3.1G 3.0G 51% / tmpfs 184M 0 184M 0% /dev/shm /dev/sdb1 82G 65G 18G 79% /mnt/hd root@arc:~# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/root 6353464 3212896 3140568 51% / tmpfs 188196 0 188196 0% /dev/shm /dev/sdb1 85758336 67196272 18562064 79% /mnt/hd root@arc:~# umount /mnt/hd/
Perhatikan, ukuran partisi nya sudah berubah dari 112G menjadi 82G.
lanjutkan ke tahap berikutnya:
STEP 3. Resize Partisi dengan fdisk
Sebenarnya, selain fdisk bisa juga menggunakan aplikasi linux lainnya untuk mengubah partisi, seperti cfdisk.
Disini penulis akan mendemokan menggunakan fdisk.
Pertanyaannya adalah, berapakah besar ukuran partisi (dalam satuan hardisk sectors) yang harus dialokasikan untuk ukuran filesystem sebesar “85758336″ ?
NB : Angka 85758336 adalah besar 1K-blocks /dev/sdb1 pada step sebelumnya.
Pengetahuan dasar untuk hardisk:
1 Sector adalah 2 Blocks
Akhir sectors untuk suatu blocks unit = ( blocks unit * 2 ) + StartSectors – 1
Bagaimana dengan hardisk kita:
root@arc:~# fdisk /dev/sdb WARNING: DOS-compatible mode is deprecated. It's strongly recommended to switch off the mode (command 'c') and change display units to sectors (command 'u'). Command (m for help): u Changing display/entry units to sectors Command (m for help): p Disk /dev/sdb: 120.0 GB, 120034123776 bytes 255 heads, 63 sectors/track, 14593 cylinders, total 234441648 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0c690c68 Device Boot Start End Blocks Id System /dev/sdb1 63 234436544 117218241 83 Linux Command (m for help): q
Perhatikan, Start sector di atas adalah 63.
Kemudian, untuk amannya, saya akan menambahkan 100MB lebih besar pada ukuran partisi dibandingkan ukuran filesystem.
INGAT: Lebih baik melebihkan ukuran Partisi daripada kekurangan. Kekurangan jumlah size partisi = DATA CORRUPT!
Jadi, sekarang kita memiliki variabel :
Start Sector : 63
Blocks yang diinginkan : 85758336
Tambahan size : 100MB
Solusi :
Akhir sectors untuk suatu blocks unit = ( blocks unit * 2 ) + StartSectors – 1
Akhir sectors untuk 85758336 = (85758336 * 2) + 63 – 1
Akhir sectors untuk 85758336 = 171516734
Tambahan size dikonversi ke sectors :
100MB = 100 * 1024 * 1024 = 104857600 bytes
sectors = 104857600 bytes / 512 bytes = 204800 sectors
blocks = 1/2 * sectors
blocks = 204800 = 102400 blocks
Karena ada tambahan 100MB ini, maka perhitungan berubah:
Total Blocks yang dibutuhkan = 85758336 + 102400 = 85860736
Akhir sectors dari block 85860736 = (85860736 * 2) + 63 – 1 = 171721534
Selanjutnya, mengubah partisi menggunakan fdisk dengan cara delete partisi lama, dan recreate partisi baru dengan start sectors yang sama dan menggunakan end sectors sesuai perhitungan.
INGAT : START SECTORS harus SAMA dengan Partisi Lama.
root@arc:~# fdisk /dev/sdb
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): u
Changing display/entry units to sectors
Command (m for help): p
Disk /dev/sdb: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders, total 234441648 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0c690c68
Device Boot Start End Blocks Id System
/dev/sdb1 63 234436544 117218241 83 Linux
Command (m for help): d
Selected partition 1
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First sector (63-234441647, default 63):
Using default value 63
Last sector, +sectors or +size{K,M,G} (63-234441647, default 234441647): 171721534
Command (m for help): p
Disk /dev/sdb: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders, total 234441648 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0c690c68
Device Boot Start End Blocks Id System
/dev/sdb1 63 171721534 85860736 83 Linux
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
Pastikan dengan pengecekan reiserfsck bahwa TIDAK ADA DATA CORRUPT :
root@arc:~# reiserfsck /dev/sdb1 reiserfsck 3.6.21 (2009 www.namesys.com) ************************************************************* ** If you are using the latest reiserfsprogs and it fails ** ** please email bug reports to reiserfs-list@namesys.com, ** ** providing as much information as possible -- your ** ** hardware, kernel, patches, settings, all reiserfsck ** ** messages (including version), the reiserfsck logfile, ** ** check the syslog file for any related information. ** ** If you would like advice on using this program, support ** ** is available for $25 at www.namesys.com/support.html. ** ************************************************************* Will read-only check consistency of the filesystem on /dev/sdb1 Will put log info to 'stdout' Do you want to run this program?[N/Yes] (note need to type Yes if you do):Yes ########### reiserfsck --check started at Mon Dec 20 02:08:31 2010 ########### Replaying journal: Done. Reiserfs journal '/dev/sdb1' in blocks [18..8211]: 0 transactions replayed Checking internal tree.. finished Comparing bitmaps..finished Checking Semantic tree: finished No corruptions found There are on the filesystem: Leaves 21848 Internal nodes 150 Directories 26963 Other files 49887 Data block pointers 16798005 (29144 of them are zero) Safe links 0 ########### reiserfsck finished at Mon Dec 20 02:11:03 2010 ########### root@arc:~#
Selamat! Anda sudah berhasil me-resize filesystem dan partisi Reiserfs. 
OPTIONAL
Anda bisa me-resize agar filesystem di sdb1 menggunakan seluruh partisi sdb1 (termasuk alokasi 100MB) yang kita persiapkan di awal:
root@arc:~# resize_reiserfs /dev/sdb1 resize_reiserfs 3.6.21 (2009 www.namesys.com) ReiserFS report: blocksize 4096 block count 21465184 (21440240) free blocks 4665459 (4640516) bitmap block count 656 (655) Syncing..done resize_reiserfs: Resizing finished successfully. root@arc:~# root@arc:~# mount /dev/sdb1 /mnt/hd/ root@arc:~# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/root 6353464 3212912 3140552 51% / tmpfs 188196 0 188196 0% /dev/shm /dev/sdb1 85858108 67196272 18661836 79% /mnt/hd root@arc:~# umount /mnt/hd/
Sekarang, seluruh partisi sdb1 sudah dipergunakan dengan format filesystem reiserfs.
STEP 4. Membuat partisi baru sdb2
Tetap menggunakan aplikasi fdisk, kita akan membuat partisi baru dengan starting sectornya adalah ending sector partisi sdb1 dan endingnya adalah sampai sector terakhir.
root@arc:~# fdisk /dev/sdb
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): u
Changing display/entry units to sectors
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 2
First sector (171721535-234441647, default 171721535):
Using default value 171721535
Last sector, +sectors or +size{K,M,G} (171721535-234441647, default 234441647):
Using default value 234441647
Command (m for help): p
Disk /dev/sdb: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders, total 234441648 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0c690c68
Device Boot Start End Blocks Id System
/dev/sdb1 63 171721534 85860736 83 Linux
/dev/sdb2 171721535 234441647 31360056+ 83 Linux
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
root@arc:~#
Disini, partisi sudah sukses dibuat. Tetapi system Linux/Kernel belum bisa mengenali dan memproses partisi ini. Pada beberapa hardware PC dibutuhkan restart mesin agar system bisa membaca perubahan baru.
Namun, pada beberapa mesin server kelas terbaru, restart tidak lagi dibutuhkan. Linux bisa mengenali perubahan ini langsung.
Ok, sekarang kita lanjut dengan restart system.
root@arc:~# reboot
setelah reboot, kita lanjutkan dengan memformat sdb2 yang telah kita buat:
root@arc:~# mkreiserfs /dev/sdb2 mkreiserfs 3.6.21 (2009 www.namesys.com) A pair of credits: Jeremy Fitzhardinge wrote the teahash.c code for V3. Colin Plumb also contributed to that. Chris Mason wrote the journaling code for V3, which was enormously more useful to users than just waiting until we could create a wandering log filesystem as Hans would have unwisely done without him. Jeff Mahoney optimized the bitmap scanning code for V3, and performed the big endian cleanups. Guessing about desired format.. Kernel 2.6.33.4 is running. Format 3.6 with standard journal Count of blocks on the device: 7840000 Number of blocks consumed by mkreiserfs formatting process: 8451 Blocksize: 4096 Hash function used to sort names: "r5" Journal Size 8193 blocks (first block 18) Journal Max transaction length 1024 inode generation number: 0 UUID: b76c8370-6769-4720-b340-efdfe539a1b8 ATTENTION: YOU SHOULD REBOOT AFTER FDISK! ALL DATA WILL BE LOST ON '/dev/sdb2'! Continue (y/n):y Initializing journal - 0%....20%....40%....60%....80%....100% Syncing..ok ReiserFS is successfully created on /dev/sdb2. root@arc:~# mount /dev/sdb2 /mnt/hd/ root@arc:~# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/root 6353464 3212968 3140496 51% / tmpfs 188196 0 188196 0% /dev/shm /dev/sdb2 31359036 32840 31326196 1% /mnt/hd root@arc:~# umount /mnt/hd/
DONE.
Selamat mencoba.
REF : – http://en.wikipedia.org/wiki/Cylinder-head-sector
- http://linux.about.com/library/cmd/blcmdl8_resize_reiserfs.htm
- Pengalaman Penulis.
filesystem, partition, reiserfs, reiserfschk, resize partition, resize_reiserfs
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